焊接制造
Overview
The HAYNES® and HASTELLOY® alloys fall into two main categories:
Corrosion-resistant Alloys (CRA), which are generally used at temperatures below 1000°F, and are able to withstand corrosive liquids.
High-temperature Alloys (HTA), which are generally used above 1000°F, at which temperatures they possess considerable strength and resistance to hot air and/or other hot gases.
The high-temperature alloys can also be sub-categorized according to the mechanism used to provide their strength. Many of the alloys contain significant quantities of atomically-large elements; these provide strength through a mechanism known as solid-solution strengthening. Other HTA materials use a mechanism known as age-hardening (also known as precipitation-hardening) to attain the required strength levels. There is also one age-hardenable, corrosion-resistant alloy.
The heat treatments required to strengthen the age-hardenable materials are normally performed after welding and hot/cold-working, and prior to these heat treatments, there is much in common with the fabrication techniques/parameters employed with the solid-solution strengthened alloys, as long as they are supplied in the annealed condition.
As with the stainless steels and other alloy systems, it is advantageous to have a rudimentary understanding of the metallurgical changes that might occur in the HAYNES® and HASTELLOY® alloys, if exposed to the heat of welding, the high temperatures involved with hot-working, or the effects of annealing after cold-working. If brazing is to be attempted, it is very important to understand how the temperatures involved with brazing might affect the HAYNES® and HASTELLOY® materials, or conversely how subsequent age-hardening (in the case of the age-hardenable alloys) or annealing treatments (in the case of any of the alloys) might affect the brazed joint.
In addition to the general purpose alloys manufactured by Haynes International, there are several special purpose alloys, requiring different fabrication approaches. One is a titanium alloy made only in the form of tubulars, and for which fabrication references are given. One is a high-temperature, nickel-based alloy that requires a nitrogen diffusion treatment to impart strength to the material, and for which there are some specific fabrication issues. The other two are cobalt-based, wear-resistant alloys, one of which is not normally welded or formed; the other is easily welded, but somewhat resistant to cold-working due to a high work-hardening rate.
Haynes International Alloys
High-temperature Alloys (HTA)
High-temperature Alloys (HTA) | ||
---|---|---|
Base | Solid-Solution | Age-Hardenable |
Nickel |
N, S, W, X 75 214®, 230® 617®, 625, 625SQ® HR-120®, HR-160®, HR-224®, HR-235® |
242®, 244®, 263, 282® 718 R-41 Waspaloy X-750 |
Cobalt |
25, 188 |
- |
Iron |
556®, MULTIMET® |
- |
Corrosion-resistant Alloys (CRA) | ||
---|---|---|
Base | Solid-Solution | Age-Hardenable |
Nickel |
B-3® C-4, C-22®, C-276, C-2000® G-30®, G-35® HYBRID-BC1® |
C-22HS® |
Lightweight Alloy (LA) | ||
---|---|---|
Base | Age-Hardenable | |
Titanium | Ti-3Al-2.5V |
High-temperature Alloy (HTA-NS) | ||
---|---|---|
Base | Nitrogen-Strengthenable | |
Cobalt |
NS-163® |
Wear-resistant Alloy (WRA) | ||
---|---|---|
Base | - | |
Cobalt | 6B |
Wear & Corrosion-resistant Alloy (WCRA) | |
---|---|
Base | - |
Cobalt |
ULTIMET® |
Wire and Welding Product Forms
Standard product size range for wire and welding consumables:
- Loose Coils: 0.030 – 0.187” (0.76 – 4.70mm) diameters
- Precision Layer Wound Wire: 0.030 – 0.093” (0.76 – 2.40mm) diameters
- Cut-length Wire: 0.030 – 0.187” (0.76 – 4.70mm) diameters
- Wire Rod for Redraw: 0.218 – 0.275” (5.50 – 7.00mm) diameters
- Coated Electrodes: 0.093 – 0.187” (0.187 – 4.70mm) diameters
- Drum Packs: 0.035 – 0.125″ (0.88 – 3.17mm) diameters. We offer 250 LB – 500 LB drums.
If you require a non-standard size, please contact one of our sales representatives.
Our Wire Products Manufacturing Facility , located in Mountain Home, North Carolina, manufactures finished high-performance alloy wire and welding consumables. The Mountain Home plant is located on approximately 29 acres of land, and includes approximately 100,000 square feet of building space. Finished wire products are also warehoused at this facility.
The Wire Facility receives HASTELLOY® and HAYNES® alloy rod coil from the main manufacturing facility in Kokomo, Indiana. The product is melted in Kokomo, rolled into rod coil, and then shipped to the Wire Products Manufacturing Facility. The majority of the rod coil is 0.218” (5.50mm). The Wire Facility also produces many other nickel alloys and stainless steel grades rod coils from various suppliers throughout the world. The products produced include:
- Round wire only in MIG, TIG, loose coils, coated electrodes, and spools
- Sizes from 0.030” to 0.156” for welding products and, as small as, 0.008” in fine wire
Common medical applications include stents, bone drill bits, cerclage cables, guide rods, orthopedic cables and heart valves.
Other wire products for the medical industry:
- 304V (ASTM F899)
- 316LVM (ASTM A580, ASTM F138)
- 420DVM (ASTM A580, ASTM F899)
- Nickel 200/201/205 (ASTM B160-05)
- NiCr 80 (ASTM-B-344)
High-speed, in-line cleaner for finished wire
Manufacturing Equipment
- 4 Morgan Draw Benches
- 6 Barcro Intermediate Draw Benches
- 12 Bull Blocks
- 32 Fine Wire Drawing Machines
- 5 Heavy Wire Strand Annealing Lines
- 5 Fine Wire Strand Annealing Lines
- 2 Ultrasonic Cleaners
- 2 Precision Level Winders
- 6 Straighten and Cut Machines
- 1 Flag Tag Machine
The GIMAX Precision Winder produces high-quality layer wound welding spools.
Rigorous positive material identifications are built into every product.
Certifications and Approvals
- ISO 9001 CERTIFIED
- AS9100 CERTIFIED
- Approved for GE Aviation S-1000
- Approved for Pratt & Whitney LCS
- Approved for Rolls Royce RR9000: SABRE
Wire is available in loose coil form in standard diameters.
Hot-working
The HAYNES® and HASTELLOY® alloys can be hot-worked into various shapes; however, they can be more sensitive to the amounts and rates of hot-reduction than the austenitic stainless steels. In addition, the hot-working temperature ranges for the HAYNES® and HASTELLOY® alloys are quite narrow, and careful attention to hot-working parameters is necessary
In developing suitable hot-working practices, particular attention should be paid to the solidus of the alloy in question (the temperature at which the alloy begins to melt), the high strengths of the HAYNES® and HASTELLOY® alloys at elevated temperatures, their high work-hardening rates, and their low-thermal conductivities. Furthermore, their resistance to deformation increases markedly as the temperature falls to the low end of the hot-working range.
Accordingly, hot-working practices that incorporate high (heavy) initial reductions, followed by moderate final reductions, coupled with frequent re-heating, generally yield the best results. In addition, slow deformation rates tend to minimize adiabatic heating and applied force requirements.
*Following any hot-working operation, the HAYNES® and HASTELLOY® alloys should be annealed, to return them to their optimal condition for service, age-hardening (in the case of the age-hardenable alloys), or for further fabrication. Annealing temperatures and techniques are detailed in the heat treatment section.
Melting Temperature Ranges
Melting Temperature Range | ||||
---|---|---|---|---|
Alloy | Solidus* | Liquidus** | ||
- | °F | °C | °F | °C |
B-3® | 2500 | 1370 | 2585 | 1418 |
C-4 | - | - | ||
C-22® | 2475 | 1357 | 2550 | 1399 |
C-22HS® | 2380 | 1304 | 2495 | 1368 |
C-276 | 2415 | 1323 | 2500 | 1371 |
C-2000® | 2422 | 328 | 2476 | 1358 |
G-30® | - | - | ||
G-35® | 2430 | 1332 | 2482 | 1361 |
HYBRID-BC1® | 2448 | 1342 | 2509 | 1376 |
N | 2375 | 1302 | 2550 | 1399 |
ULTIMET® | 2430 | 1332 | 2470 | 1354 |
25 | 2425 | 1329 | 2570 | 1410 |
75 | 2445 | 1341 | 2515 | 1379 |
188 | 2400 | 1316 | 2570 | 1410 |
214® | 2475 | 1357 | 2550 | 1399 |
230® | 2375 | 1302 | 2500 | 1371 |
242® | 2350 | 1288 | 2510 | 1377 |
244® | 2480 | 1360 | 2550 | 1399 |
263 | 2370 | 1299 | 2470 | 1354 |
282® | 2370 | 1299 | 2510 | 1377 |
556® | 2425 | 1329 | 2480 | 1360 |
617 | 2430 | 1332 | 2510 | 1377 |
625 | 2350 | 1288 | 2460 | 1349 |
625SQ® | 2350 | 1288 | 2460 | 1349 |
718 | 2300 | 1260 | 2435 | 1335 |
HR-120® | 2478 | 1359 | 2542 | 1395 |
HR-160® | 2360 | 1293 | 2500 | 1371 |
HR-224® | 2449 | 1343 | 2510 | 1377 |
HR-235® | 2401 | 1316 | 2473 | 1356 |
MULTIMET® | 2350 | 1288 | 2470 | 1354 |
R-41 | 2385 | 1307 | 2450 | 1343 |
S | 2435 | 1335 | 2516 | 1380 |
W | 2350 | 1288 | 2510 | 1377 |
Waspaloy | 2425 | 132 | 2475 | 1357 |
X | 2300 | 1260 | 2470 | 1354 |
X-750 | 2540 | 1393 | 2600 | 1427 |
*Temperature at which alloy starts to melt
**Temperature at which alloy is fully molten
Forging
Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
The following procedures are recommended for forging of the HAYNES® and HASTELLOY® alloys:
- Soak billets or ingots at the forging start temperature for at least 30 minutes per inch of thickness. The use of a calibrated optical pyrometer is essential.
- The stock should be turned frequently to make sure that it is heated evenly. Direct flame impingement on the alloy must be avoided.
- Forging should begin immediately after withdrawal from the furnace. A short time lapse may allow surface temperatures to drop as much as 100-200°F (55-110°C). Do not raise the forging temperature to compensate for heat loss, as this may cause incipient melting.
- Moderately heavy reductions (25-40%) are beneficial, to maintain as much internal heat as possible, thus minimizing grain coarsening and the number of re-heatings. Reductions greater than 40% per pass should be avoided.
- Care must be taken to impart sufficient hot-work during forging to ensure that the appropriate structure and properties are achieved in the final part. For parts with large cross-sections, it is advisable to include a number of forging upsets in the hot-working schedule, to allow for adequate forging reductions. Upset L/D ratios of 3:1 are generally acceptable.
- Light-reduction finish sizing sessions should generally be avoided. If required, they should be performed at the lower end of the forging temperature range.
- Do not make radical changes in the cross-sectional shape, such as going directly from a square to a round, during initial forming stages. Instead, go from a square to a “round cornered square”, then to an octagon, then to a round.
- Remove (condition) any cracks or tears developed during forging. This can be done at intermediate stages, between forging sessions.
Forging/Hot-working Temperature Ranges
Forging/Hot-Working Temperature | ||||
---|---|---|---|---|
Alloy | Start Temperature* | Finish Temperature** | ||
- | °F | °C | °F | °C |
B-3® | 2275 | 1246 | 1750 | 954 |
C-4 | 2200 | 1204 | 1750 | 954 |
C-22® | 2250 | 1232 | 1750 | 954 |
C-22HS® | 2250 | 1232 | 1750 | 954 |
C-276 | 2250 | 1232 | 1750 | 954 |
C-2000® | 2250 | 1232 | 1750 | 954 |
G-30® | 2200 | 1204 | 1800 | 982 |
G-35® | 2200 | 1204 | 1750 | 954 |
HYBRID-BC1® | 2250 | 1232 | - | |
N | 2200 | 1204 | 1750 | 954 |
ULTIMET® | 2200 | 1204 | 1750 | 954 |
25 | 2200 | 1204 | 1750 | 954 |
75 | 2200 | 1204 | 1700 | 927 |
188 | 2150 | 1177 | 1700 | 927 |
214® | 2150 | 1177 | 1800 | 982 |
230® | 2200 | 1204 | 1700 | 927 |
242® | 2125 | 1163 | 1750 | 954 |
244® | - | - | ||
263 | 2150 | 1177 | 1750 | 954 |
282® | 2125 | 1163 | 1850 | 1010 |
556® | 2150 | 1177 | 1750 | 954 |
617 | 2125 | 1163 | 1600 | 871 |
625 | 2150 | 1177 | 1600 | 871 |
625SQ® | - | - | ||
718 | 2050 | 1121 | 1650 | 899 |
HR-120® | 2150 | 1177 | 1700 | 927 |
HR-160® | 2050 | 1121 | 1600 | 871 |
HR-224® | - | - | ||
HR-235® | 2250 | 1232 | 1750 | 954 |
MULTIMET® | 2150 | 1177 | 1700 | 927 |
R-41 | 2150 | 1177 | 1850 | 1010 |
S | 2100 | 1149 | 1700 | 927 |
W | 2240 | 1227 | 1800 | 982 |
Waspaloy | 2150 | 1177 | 1850 | 1010 |
X | 2100 | 1149 | 1750 | 954 |
X-750 | 2150 | 1177 | 1750 | 954 |
*Maximum
**Dependent upon the nature and degree of working
Hot-rolling
Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
Hot rolling of the HAYNES® and HASTELLOY® alloys can be performed to produce conventional rolled forms, such as bars, rings, and flats. The hot rolling temperature range is the same as that listed above (in the Forging section, under Forging/Hot-working Temperature Ranges).
Moderate reductions per pass (15 to 20 percent reduction in area), and rolling speeds of 200 to 300 surface feet per minute tend to provide good results, without overloading the mill. The total reduction per session should be at least 20 to 30 percent. It is usual to finish at the low end of the hot-working temperature range, since this generally provides the optimum structure and properties.
Care should be taken to ensure that the work piece is thoroughly soaked at the hot working start temperature before rolling. Frequent re-heating may be required during hot-rolling, to keep the temperature of the work piece in the hot working range.
Hot-forming
Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
The hot-forming of plates into components, such as dished heads is normally performed by cold-pressing or spinning, with intermediate anneals. However, sometimes the size and thickness of the material is such that hot-forming is necessary.
When hot-forming is required, the start temperature (to which the furnace is heated) is approximately mid-way between the annealing temperature (of the alloy in question) and its lower (finish) forging temperature. During hot-forming, the temperature of the piece should not fall below the lower (finish) forging temperature. Re-heating may be necessary to maintain the correct hot forming temperature, and dies should be warmed to avoid excessive chilling of the surfaces.
Other Hot-Working Processes
Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
The HAYNES® and HASTELLOY® alloys are amenable to several other hot-working processes, such as hot-extrusion and hot-spinning. Impact extrusion should be performed at the solution annealing temperature of the alloy involved. Uniform and accurate temperatures throughout the work-piece are necessary during impact extrusion, and re-strikes should be avoided. The parameters for hot extrusion and hot spinning are specific to the exact nature of the intended work and material. For more information, please contact our technical support team.
Cold-working
The HAYNES® and HASTELLOY® alloys can be readily formed into various configurations by cold-working. Since they are generally stronger, and work harden more rapidly, than the austenitic stainless steels, the application of greater force is normally required to achieve the same amount of cold deformation. The higher yield strengths of the HAYNES® and HASTELLOY® alloys may also result in greater spring-back after cold forming, relative to the austenitic stainless steels. Furthermore, rapid work hardening may necessitate more frequent annealing treatments between forming steps, to attain the final shape. Graphs illustrating the effects of cold-work upon the hardness, yield strength, and ductility of some of the HAYNES® and HASTELLOY® alloys are shown below.
Effect of Cold-work on Hardness Applicable to:
Effect of Cold-Work on Yield Strength:
Effect of Cold-work on Elongation Applicable to:
Generally, as-supplied materials (annealed at the Haynes International mills) have sufficient ductility for mild forming. However, for higher levels of cold deformation, where cracking is a possibility due to a reduction in ductility, a series of successive forming operations is recommended, each followed by an intermediate annealing treatment. Under most circumstances, this should be a solution anneal (the temperatures for which are given in the Heat Treatment section). A final (solution) anneal is recommended after the completion of such successive forming/annealing operations, to restore the material to its optimum condition and properties. This is particularly important for restoring resistance to stress corrosion cracking, in the case of the corrosion-resistant alloys.
However, the annealing of material subjected to low levels of cold-work (less than about 7 to 10% outer fiber elongation) is generally not suggested since it can result in abnormal grain growth, leading to a surface condition known as “orange peel” or “alligator hide”, and significantly affect properties. Please refer to any additional ‘Fabrication and Welding’ information for the specific alloy or contact Haynes International for further guidance.
As discussed below, it is very important that any lubricants, or other foreign matter, be carefully removed from the surfaces of the workpiece prior to any intermediate (or final) annealing treatment, to prevent the diffusion of detrimental elements into the alloy.
It is highly recommended that any scales (i.e. surface films) caused by intermediate annealing treatments be removed prior to the next forming operation by pickling or mechanical means.
Lubrication is a significant consideration for successfully cold-working the HAYNES® and HASTELLOY® alloys. Although lubrication is not normally required for simple bending operations, the use of lubricants may be essential for other forming operations, such as cold-drawing. Mild forming operations can be successfully completed using lard oil or castor oil, which are easily removed. More severe forming operations require metallic soaps or chlorinated/sulfo-chlorinated oils. When sulfo-chlorinated oils are used, the work-piece must be carefully cleaned in a de-greaser or alkaline cleaner, after each step (to prevent sulfur diffusion into the alloy during subsequent annealing).
Lubricants that contain white lead, zinc compounds, or molybdenum disulfide are not recommended because they are difficult to remove and can cause lead, zinc, or sulfur to diffuse into the alloy during subsequent annealing, resulting in severe embrittlement. For the same reason, any die materials, lubricants, or foreign matter should be carefully removed from the work-piece before any intermediate or final annealing treatments.
Bending, Roll-Forming, Roll-Bending, and Press-Braking
Recommended Procedures Applicable to:
HAYNES® and HASTELLOY® sheets and plates are amenable to simple bending, roll-forming, roll-bending, and press-braking operations. Lubrication is not generally required for such operations. Minimum bend radius guidelines are given in the table below, but may vary from alloy to alloy.
Material Thickness | Suggested Minimum Bend Radius* | ||
---|---|---|---|
in | mm | - | |
<0.050 | <1.27 | 1T | |
0.050-0.187 | 1.27-4.75 | 1.5T | |
0.188-0.500 | 4.76-12.70 | 2T | |
0.501-0.750 | 12.71-19.05 | 3T | |
0.751-1.000 | 19.06-25.40 | 4T |
*T = Material thickness
Thick sections may require multiple steps, with intermediate annealing treatments to restore ductility. These treatments should be performed in accordance with the recommendations given in the Heat Treatment section, and again care must be taken to clean the surfaces of the work-piece prior to annealing.
Deep Drawing, Stretch Forming, and Hydroforming
Recommended Procedures Applicable to:
The HAYNES® and HASTELLOY® alloys are amenable to deep drawing, stretch forming, hydro-forming, and such like. Lubrication is generally required for these processes. In the case of the high temperature alloys, fine-grained starting material possessing superior forming characteristics may be available. As with bending operations, thick sections may require multiple steps, with intermediate annealing treatments to restore ductility. These treatments should be performed in accordance with the recommendations given in the Heat Treatment section, and again care must be taken to clean the surfaces of the work-piece prior to annealing.
As a guide to the formability of the high-temperature alloys, Olsen Cup (lubricated) test results are provided below for some of the alloys, along with 310 stainless steel for comparison.
Alloy | Average Olsen Cup Depth* | ||
---|---|---|---|
- | in | mm | |
25 | 0.443 | 11.3 | |
188 | 0.490 | 12.4 | |
230® | 0.460 | 11.7 | |
556® | 0.480 | 12.2 | |
625 | 0.440 | 11.2 | |
S | 0.513 | 13.0 | |
X | 0.484 | 12.3 | |
310 Stainless Steel | 0.505 | 12.8 |
*Average of 3 to 12 measurements on 0.040-0.070 in (1.0-1.75 mm) thick sheet
Spinning and Shear Spinning
Recommended Procedures Applicable to:
Spinning is a deformation process for forming sheet metal or tubing into seamless hollow cylinders, cone hemispheres, or other symmetrical circular shapes, by a combination of rotation and force. There are two basic forms, known as manual spinning and power (or shear) spinning. In the former method, no appreciable thinning of the metal occurs, whereas in the latter, metal is thinned as a result of shear forces.
Nearly all HAYNES® and HASTELLOY® alloys can be spin formed, generally at room temperature. The control of quality, including freedom from wrinkles and scratches, in addition to dimensional accuracy, is largely dependent upon operator skill. The primary parameters that should be considered when spinning these alloys are:
- Speed
- Feed Rate
- Lubrication
- Material
- Strain Hardening Characteristics
- Tool Material, Design, and Surface Finish
- Power of the Machine
Optimum combinations of speed, feed, and pressure are normally determined experimentally when a “new job” is set up. During continuous operation, changes in the temperature of the mandrel and spinning tool may necessitate the adjustment of pressure, speed, and feed to obtain uniform results.
Lubrication should be used in all spinning operations. The usual practice is to apply lubricant to the blank prior to loading of the machine. It may be necessary to add lubricants during operation. During spinning, the work-piece and tools should be flooded with a coolant, such as an emulsion of soluble oil in water.
Sulfurized or chlorinated lubricants should not be used, since the spinning operation might burnish the lubricant into the surface, resulting in detrimental surface effects (due to diffusion of sulfur and/or chlorine) during any subsequent annealing treatments. If these types of lubricant are used accidentally, they should be thoroughly removed (by grinding, polishing, or pickling) prior to any intermediate or final anneal.
The tool material, work-piece design, and surface finish are all very important in achieving trouble-free operation. Mandrels used in spinning must be hard, wear-resistant, and resistant to the fatigue resulting from normal eccentric loading.
As is the case for other cold-forming operations, parts produced by cold spinning should be intermediate and final annealed in accordance with the recommendations in the Heat-Treatment section of this guide.
Tube-forming
Recommended Procedures Applicable to:
The HAYNES® and HASTELLOY® alloys can be cold formed in standard pipe and tube bending equipment. The minimum recommended bending radius, from the radius point to the centerline of the tube, is three times the tube diameter, for most bending operations. When measured from centerline to centerline of the “hairpin” straight legs, it is six times the tube diameter. On the other hand, there are some combinations of tube diameter and wall thickness where a bending radius of twice the tube diameter is possible (from the radius point to the centerline of the tube).
As the ratio of tube diameter to wall thickness increases, the need for internal and external support becomes increasingly important, in order to prevent distortion. If too small a bending radius is used, then wrinkles, poor ovality, and buckling can occur (in addition to wall thinning).
Punching
Recommended Procedures Applicable to:
Punching of the HAYNES® and HASTELLOY® alloys is usually performed at room temperature. Perforation should be limited to a minimum diameter of twice the gage thickness. The center-to-center dimension should be approximately three to four times the diameter of the hole.
Punch to Die Clearances per Side | |
---|---|
Annealed Sheet up to 0.125 in (3.2 mm) | 3-5% of Thickness |
Annealed Sheet or Plate over 0.125 in (3.2 mm) | 5-10% of Thickness |
Cutting and Shearing
Recommended Procedures Applicable to:
In view of the high strengths and high work-hardening rates of the HAYNES® and HASTELLOY® alloys (relative to many austenitic stainless steels), band saw cutting is generally ineffective. For flat products, shearing can be successful on “scissor-type” shears rated for carbon steel thicknesses at least 50% above the alloy thickness involved.
Generally, alloy thicknesses up to 0.4375 in (11.1 mm) are shear-able, while thicker material is normally cut by abrasive saw or plasma arc. Abrasive water-jet cutting is not normally recommended, but may be practical in some cases. Bar and tubular products are normally cut using abrasive saws.
Resin-bonded, aluminum oxide wheels are used to successfully cut the HAYNES® and HASTELLOY® alloys. A typical grain and grade designation is 86A361-LB25W EXC-E.
The HAYNES® and HASTELLOY® alloys can be plasma arc cut using any conventional system. The best arc quality is achieved using a mixture of argon and hydrogen gases. Nitrogen gas can be substituted for hydrogen; however, this will result in a cut of reduced quality. Shop air and oxygen-containing gases are unsuitable and should be avoided when plasma cutting these alloys.
Oxy-acetylene cutting of these alloys is not recommended. Air carbon arc cutting is feasible, but subsequent grinding, to remove any carbon contamination, is likely to be required.
Heat Treatment
Recommended Procedures and Temperatures Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
The heat treatment of the HAYNES® and HASTELLOY® alloys is a very important topic. In the production of these wrought materials, there are many hot- and cold-reduction steps, between which intermediate heat treatments are necessary, to restore the optimum properties, in particular ductility. In the case of the corrosion-resistant alloys, these intermediate heat treatments are generally solution-annealing treatments. In the case of the high-temperature alloys, this is not necessarily so.
Once the materials have reached their final sizes, they are given a final anneal. This is usually a solution-anneal; however, a few high-temperature alloys (HTA) are final annealed at an adjusted temperature, to control grain size, or some other microstructural feature.
Subsequent fabrication of these as-supplied materials can again involve hot- or cold-working, as discussed in the Hot-working and Cold-working sections of this guide. Again, working often involves steps, with intermediate annealing (normally solution-annealing for the CRA materials) treatments to restore ductility. Beyond that, fabricated components will require a final anneal (normally a solution-anneal for the CRA materials), to restore optimum properties prior to use, or (in the case of the age-hardenable alloys) to prepare them for age-hardening.
Applicable to:
Corrosion-resistant Alloys
The compositions of the corrosion-resistant alloys (CRA) comprise a nickel base, substantial additions of chromium and/or molybdenum (in some cases partially replaced by tungsten), small additions such as copper (to enhance resistance to certain media) and iron (to allow the use of less expensive raw materials), and minor additions such as aluminum and manganese, which help remove deleterious elements such as oxygen and sulfur, during melting. As-supplied, they generally exhibit single phase (face-centered cubic, or gamma) wrought microstructures.
In most cases, the presence of a single phase microstructure in as-supplied (CRA) materials is due to a high temperature, solution-annealing treatment, followed by quenching (rapid cooling), to “lock-in” the high-temperature structure. Left to cool slowly, most of these alloys would contain second phases (albeit in small amounts), commonly within the structural grain boundaries, as a result of the fact that the combined contents of the alloying additions exceed their solubility limits.
This is exacerbated by the fact that, despite sophisticated melting techniques and procedures, traces of unwanted elements (with very low solubility), such as carbon and silicon, can be present. Fortunately, solution-annealing, followed by quenching (by water or cold gas), solves this problem also.
The corrosion-resistant alloys are usually supplied in the solution-annealed condition, and their normal solution-annealing temperatures are given in the table below. They represent temperatures at which phases other than gamma (and, in rare cases, primary carbides and/or nitrides) dissolve, yet provide grain sizes within the range known to impart good mechanical properties. Primary carbides and/or nitrides are seen in C-4 alloy, due to the presence of titanium.
In the case of the corrosion-resistant alloys (CRA), the terms solution-annealed and mill-annealed (MA) are generally synonymous; however, the temperatures used in continuous hydrogen-annealing furnaces (in sheet production) are adjusted to compensate for the line speeds (hence time at temperature).
Solution-annealing Temperatures of the Corrosion-resistant Alloys (CRA)
Alloy | Solution-annealing Temperature* | Type of Quench | |
---|---|---|---|
- | °F | °C | - |
B-3® | 1950 | 1066 | WQ or RAC |
C-4 | 1950 | 1066 | WQ or RAC |
C-22® | 2050 | 1121 | WQ or RAC |
C-22HS® | 1975 | 1079 | WQ or RAC |
C-276 | 2050 | 1121 | WQ or RAC |
C-2000® | 2100 | 1149 | WQ or RAC |
G-30® | 2150 | 1177 | WQ or RAC |
G-35® | 2050 | 1121 | WQ or RAC |
HYBRID-BC1® | 2100 | 1149 | WQ or RAC |
*Plus or Minus 25°F (14°C)
WQ = Water Quench (Preferred); RAC = Rapid Air Cool
There are no specific rules regarding the times required to heat up, then anneal, the corrosion-resistant alloys (CRA), since there are many types of furnace, involving different modes of loading, unloading, and operation. There are only general guidelines.
The temperature of the work-piece being annealed should be measured with an attached thermocouple, and recording of the annealing time should begin only when the entire section of the work-piece has reached the recommended annealing temperature. It should be remembered that the center of the section takes longer to reach the annealing temperature than the surface.
The general guidelines regarding time are:
- Normally, once the whole of the workpiece is at the annealing temperature, the annealing time should be between 10 and 30 minutes, depending upon the section thickness.
- The shorter times within this range should be used for thin sheet components.
- The longer times should be used for thick (heavier) sections.
Rapid cooling is essential after annealing, to prevent the nucleation and growth of deleterious second phase precipitates in the microstructure, particularly at the grain boundaries. Water quenching is preferred, and highly recommended for materials thicker than 3/8 in (9.5 mm). Rapid air cooling has been used for thin sections. The time between removal from the furnace and the start of quenching must be as short as possible (and certainly less than three minutes).
Special precautions are necessary with B-3® alloy. Although more stable than other nickel-molybdenum alloys (particularly its predecessor, B-2® alloy), it is still prone to significant, deleterious, microstructural changes in the temperature range 1100-1500°F (593-816°C), especially after being cold-worked. Thus, care must be taken to avoid exposing B-3® alloy to temperatures within this range for any length of time. B-3®alloy should be annealed in furnaces pre-heated to the annealing temperature (1950°F/1066°C), and with sufficient thermal capacity to ensure rapid recovery of the temperature after loading of the furnace with the B-3® work-piece.
One of the potential problems associated with these microstructural changes (which can occur during heating to the annealing temperature) in the nickel-molybdenum (B-type) alloys is cracking due to residual stresses, in cold-worked material. Shot peening of the knuckle radius and straight flange regions of cold-formed heads, to lower residual tensile stress patterns, has been found to be very beneficial in avoidance of such problems. Cold or hot formed heads should always be annealed after forming, regardless of forming strain level. This is especially important if the material is to be subsequently welded.
Applicable To:
High-temperature Alloys
The high-temperature alloys (HTA), whether based on nickel, cobalt, or a mixture of nickel, cobalt, and iron, are compositionally much more complicated. However, as in the CRA alloys, chromium is an important alloying element, enabling the formation of protective, surface films (particularly oxides) in hot gases.
Large atoms such as molybdenum and tungsten are used to provide solid-solution strength to many of the high-temperature alloys. Those relying on age-hardening for strength include significant quantities of elements such as aluminum, titanium, and niobium (columbium), which can form extremely fine precipitates of second phases (“gamma prime” and “gamma double prime”) known to be very effective strengtheners.
Aluminum can play another role in the high temperature alloys, and that is to modify the protective films (oxides, in particular) that form on the surfaces of these materials at high-temperatures, in the presence of oxygen, etc. Indeed, aluminum oxide is very adherent, stable, and protective.
Unlike the CRA materials, in which carbon is generally a negative actor, the high-temperature HAYNES® and HASTELLOY® (HTA) alloys rely upon deliberate carbon additions, or rather the carbides they induce in the microstructures, to provide the necessary levels of strength (particularly creep strength) for high-temperature service. In some cases, these carbides form during solidification of the materials (primary carbides). In other cases, they form during high-temperature exposure, in the solid state (secondary carbides).
As a consequence of the need for specific carbide types and morphologies in the HTA materials, annealing is a much more complicated subject, especially between steps in the manufacturing and fabrication processes.
The high-temperature HAYNES® and HASTELLOY® alloys are normally supplied in the solution-annealed condition, which is attained by heat treatment at the following temperatures (or within the specified ranges):
Solution-annealing Temperatures of the High-temperature Alloys (HTA)
Alloy | Solution-annealing Temperature/Range | Type of Quench | |
---|---|---|---|
- | °F | °C | - |
25 | 2150-2250 | 1177-1232 | WQ or RAC |
75 | 1925* | 1052* | WQ or RAC |
188 | 2125-2175 | 1163-1191 | WQ or RAC |
214® | 2000 | 1093 | WQ or RAC |
230® | 2125-2275 | 1163-1246 | WQ or RAC |
242® | 1900-2050 | 1038-1121 | WQ or RAC |
244® | 2000-2100 | 1093-1149 | WQ or RAC |
263 | 2100 + 25 | 1149 + 14 | WQ or RAC |
282® | 2050-2100 | 1121-1149 | WQ or RAC |
556® | 2125-2175 | 1163-1191 | WQ or RAC |
625 | 2000-2200 | 1093-1204 | WQ or RAC |
718 | 1700-1850** | 927-1010** | WQ or RAC |
HR-120® | 2150-2250 | 1177-1232 | WQ or RAC |
HR-160® | 2025-2075 | 1107-1135 | WQ or RAC |
HR-224® | WQ or RAC | ||
HR-235® | 2075-2125 | 1135-1163 | WQ or RAC |
MULTIMET® | 2150 | 1177 | WQ or RAC |
N | 2150 | 1177 | WQ or RAC |
R-41 | 2050 | 1121 | WQ or RAC |
S | 1925-2075 | 1052-1135 | WQ or RAC |
W | 2165 | 1185 | WQ or RAC |
WASPALOY | 1975 | 1079 | WQ or RAC |
X | 2125-2175 | 1163-1191 | WQ or RAC |
X-750 | 1900* | 1038* | WQ or RAC |
WQ = Water Quench (Preferred); RAC = Rapid Air Cool
*Bright (Hydrogen) Annealing Temperature
**Not Strictly a Solution-annealing Temperature Range (More a Preparatory Annealing Temperature Range)
In the solution-annealed condition, the microstructures of the high-temperature alloys (HTA) generally consist of primary carbides dispersed in a gamma phase (face-centered cubic) matrix, with essentially clean (precipitate-free) grain boundaries. For the solid-solution strengthened alloys, this is usually the optimum condition for both high-temperature service, and for room temperature fabricability.
Although the HAYNES® and HASTELLOY® alloys should not be subjected to stress relief treatments at the sort of temperatures used for the steels and stainless steels, for fear of causing the precipitation of undesirable second phases (particularly in the alloy grain boundaries), some lower annealing temperatures have been used for the high-temperature alloys (HTA) between processing steps, to restore the ductility of partially-fabricated workpieces. These so-called intermediate annealing temperatures should be used with caution, since they too are likely to result in the aforementioned grain boundary precipitation. Some minimum, intermediate annealing temperatures are given in the following table (for selected solid-solution strengthened HTA materials):
Minimum Intermediate Annealing Temperatures (HTA)
Alloy | Minimum Intermediate Annealing Temperature | |
---|---|---|
- | °F | °C |
25 | 2050 | 1121 |
188 | 2050 | 1121 |
230® | 2050 | 1121 |
556® | 1900 | 1038 |
625 | 1700 | 927 |
HR-120® | 1950 | 1066 |
HR-160® | 1950 | 1066 |
S | 1750 | 954 |
X | 1850 | 1010 |
Whether an intermediate annealing temperature (rather than a solution-annealing temperature) is appropriate between processing steps will depend upon the alloy and the effects of the lower temperature upon microstructure, and upon the nature of the subsequent operation. These issues must be studied carefully, and advice sought.
Annealing During Cold (or Warm) Forming
Applicable To:
High-temperature Alloys
The response of the HAYNES® and HASTELLOY® high-temperature alloys (HTA) to heat treatment is very dependent upon the condition of the material prior to the treatment. When the material is not in a cold- or warm-worked condition, the principal response is usually a change in the amount and morphology of the secondary carbide phases. Other minor effects might occur, but the grain structure normally remains the same (in the absence of prior cold or warm work).
When these alloys have been subjected to cold- or warm-work, the application of a solution or intermediate anneal will almost always alter the grain structure. Moreover, the amount of prior cold- or warm-work will significantly affect the grain structure, and consequently the mechanical properties of the material.
The following table indicates the effects of heat-treatments (of 5 minutes duration) at various temperatures upon the grain sizes of sheets of several high temperature alloys, subjected to different levels of cold-work.
Effects of Cold-work and Heat Treatment Temperature on Grain Size
Cold-work | Heat TreatmentTemperature | Cold-work | ||||
---|---|---|---|---|---|---|
% | °F | °C | 25 | 230® | 556® | X |
0 | None | 3.5-4 | 3.5-4 | 3.5-4 | 3.5-4 | |
10 | 1850 | 3.5-4 | 3.5-4 | 3.5-4 | NR | 3.5-4 |
1950 | 3.5-4 | 3.5-4 | 3.5-4 | NR | 3.5-4 | |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | 5-5.5 | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | 5-5.5 | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
15 | 1950 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
20 | 1850 | 3.5-4 | 3.5-4 | 3.5-4 | NR | 3.5-4 |
1950 | 3.5-4 | 3.5-4 | 3.5-4 | NR | 3.5-4 | |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | 7.5-8.5 | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | 6-6.5 | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
25 | 1950 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
30 | 1850 | 3.5-4 | 3.5-4 | 3.5-4 | NFR | 3.5-4 |
1950 | 3.5-4 | 3.5-4 | 3.5-4 | 7.5-9.5 | 3.5-4 | |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | 7-7.5 | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | 4.5-6.5 | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
40 | 1850 | 3.5-4 | 3.5-4 | 3.5-4 | 7.5-9.5 | 3.5-4 |
1950 | 3.5-4 | 3.5-4 | 3.5-4 | 8-9.5 | 3.5-4 | |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | 7-9 | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | 4.5-6.5 | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 | |
50 | 1850 | 3.5-4 | 3.5-4 | 3.5-4 | 9-10 | 3.5-4 |
1950 | 3.5-4 | 3.5-4 | 3.5-4 | 8.5-10 | 3.5-4 | |
2050 | 3.5-4 | 3.5-4 | 3.5-4 | 8-9.5 | 3.5-4 | |
2150 | 3.5-4 | 3.5-4 | 3.5-4 | 5.5-6 | 3.5-4 | |
2250 | 3.5-4 | 3.5-4 | 3.5-4 | NA | 3.5-4 |
NA=Not Available
NR= No Recrystallization Observed
NFR=Not Fully Recrystallized
The effects of cold-work plus heat treatment at various temperatures upon the mechanical properties of several solid solution strengthened, high temperature HAYNES® and HASTELLOY® alloys are shown in the following tables and figures.
Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 25 Sheet
Cold-work | Heat Treatment* Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | Hardness | |||
---|---|---|---|---|---|---|---|---|
% | °F | °C | ksi | MPa | ksi | MPa | % | HRC |
No Cold-work | No Heat Treatment | 68 | 469 | 144 | 993 | 58 | 24 | |
10 | No Heat Treatment | 124 | 855 | 182 | 1255 | 37 | 36 | |
15 | No Heat Treatment | 149 | 1027 | 178 | 1227 | 28 | 40 | |
20 | No Heat Treatment | 151 | 1041 | 193 | 1331 | 18 | 42 | |
25 | No Heat Treatment | 184 | 1269 | 232 | 1600 | 15 | 44 | |
10 | 1950 | 1066 | 98 | 676 | 163 | 1124 | 39 | 32 |
15 | 1950 | 1066 | 91 | 627 | 167 | 1151 | 44 | 30 |
20 | 1950 | 1066 | 96 | 662 | 171 | 1179 | 41 | 32 |
25 | 1950 | 1066 | 89 | 614 | 169 | 1165 | 44 | 32 |
10 | 2050 | 1121 | 74 | 510 | 157 | 1082 | 53 | 27 |
15 | 2050 | 1121 | 79 | 545 | 161 | 1110 | 52 | 28 |
20 | 2050 | 1121 | 82 | 565 | 165 | 1138 | 48 | 31 |
25 | 2050 | 1121 | 83 | 572 | 166 | 1145 | 48 | 30 |
10 | 2150 | 1177 | 67 | 462 | 148 | 1020 | 63 | 21 |
15 | 2150 | 1177 | 74 | 510 | 156 | 1076 | 55 | 26 |
20 | 2150 | 1177 | 72 | 496 | 154 | 1062 | 59 | 26 |
25 | 2150 | 1177 | 69 | 476 | 149 | 1027 | 62 | 25 |
10 | 2250 | 1232 | 69 | 476 | 144 | 993 | 64 | 95 |
15 | 2250 | 1232 | 64 | 441 | 142 | 979 | 68 | 97 |
20 | 2250 | 1232 | 62 | 427 | 135 | 931 | 69 | 97 |
25 | 2250 | 1232 | 61 | 421 | 138 | 951 | 70 | 96 |
*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRC= Hardness Rockwell “C”
Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 188 Sheet
Cold-work | Heat Treatment* Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | Hardness | |||
---|---|---|---|---|---|---|---|---|
% | °F | °C | ksi | MPa | ksi | MPa | % | HR BW/C |
No Cold-work | No Heat Treatment | 67 | 462 | 137 | 945 | 54 | 98 HRBW | |
10 | No Heat Treatment | 106 | 731 | 151 | 1041 | 45 | 32 HRC | |
20 | No Heat Treatment | 133 | 917 | 166 | 1145 | 28 | 37 HRC | |
30 | No Heat Treatment | 167 | 1151 | 195 | 1344 | 13 | 41 HRC | |
40 | No Heat Treatment | 177 | 1220 | 215 | 1482 | 10 | 44 HRC | |
10 | 1950 | 1066 | 91 | 627 | 149 | 1027 | 41 | 30 HRC |
20 | 1950 | 1066 | 88 | 607 | 153 | 1055 | 41 | 28 HRC |
30 | 1950 | 1066 | 84 | 579 | 158 | 1089 | 41 | 30 HRC |
40 | 1950 | 1066 | 91 | 627 | 163 | 1124 | 40 | 31 HRC |
10 | 2050 | 1121 | 65 | 448 | 143 | 986 | 50 | 22 HRC |
20 | 2050 | 1121 | 71 | 490 | 149 | 1027 | 47 | 25 HRC |
30 | 2050 | 1121 | 80 | 552 | 155 | 1069 | 44 | 28 HRC |
40 | 2050 | 1121 | 87 | 600 | 159 | 1096 | 43 | 30 HRC |
10 | 2150 | 1177 | 62 | 427 | 140 | 965 | 55 | 96 HRBW |
20 | 2150 | 1177 | 65 | 448 | 141 | 972 | 53 | 97 HRBW |
30 | 2150 | 1177 | 67 | 462 | 143 | 986 | 52 | 99 HRBW |
40 | 2150 | 1177 | 64 | 441 | 141 | 972 | 56 | 97 HRBW |
10 | 2250 | 1232 | 59 | 407 | 132 | 910 | 59 | 95 HRBW |
20 | 2250 | 1232 | 58 | 400 | 130 | 896 | 63 | 94 HRBW |
30 | 2250 | 1232 | 58 | 400 | 131 | 903 | 63 | 93 HRBW |
40 | 2250 | 1232 | 58 | >400 | 132 | 910 | 62 | 93 HRBW |
*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”
Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 230® Sheet
Cold-work | Heat Treatment* Temperature | 0.2% OffsetYield Strength | Ultimate Tensile Strength | Elongation | Hardness | |||
---|---|---|---|---|---|---|---|---|
% | °F | °C | ksi | MPa | ksi | MPa | % | HR BW/C |
No Cold-work | No Heat Treatment | 62 | 427 | 128 | 883 | 47 | 95 HRBW | |
10 | No Heat Treatment | 104 | 717 | 145 | 1000 | 32 | 28 HRC | |
20 | No Heat Treatment | 133 | 917 | 164 | 1131 | 17 | 35 HRC | |
30 | No Heat Treatment | 160 | 1103 | 188 | 1296 | 10 | 39 HRC | |
40 | No Heat Treatment | 172 | 1186 | 202 | 1393 | 8 | 40 HRC | |
50 | No Heat Treatment | 185 | 1276 | 215 | 1482 | 6 | 42 HRC | |
10 | 1950 | 1066 | 92 | 634 | 144 | 993 | 33 | 24 HRC |
20 | 1950 | 1066 | 81 | 558 | 142 | 979 | 36 | 26 HRC |
30 | 1950 | 1066 | 76 | 524 | 142 | 979 | 36 | 99 HRBW |
40 | 1950 | 1066 | 81 | 558 | 146 | 1007 | 32 | 23 HRC |
50 | 1950 | 1066 | 86 | 593 | 148 | 1020 | 35 | 24 HRC |
10 | 2050 | 1121 | 81 | 558 | 139 | 958 | 37 | 98 HRBW |
20 | 2050 | 1121 | 65 | 448 | 136 | 938 | 39 | 97 HRBW |
30 | 2050 | 1121 | 72 | 496 | 140 | 965 | 38 | 99 HRBW |
40 | 2050 | 1121 | 76 | 524 | 142 | 979 | 36 | 99 HRBW |
50 | 2050 | 1121 | 81 | 558 | 144 | 993 | 36 | 23 HRC |
10 | 2150 | 1177 | 56 | 386 | 130 | 896 | 44 | 92 HRBW |
20 | 2150 | 1177 | 64 | 441 | 134 | 924 | 40 | 96 HRBW |
30 | 2150 | 1177 | 70 | 483 | 138 | 951 | 39 | 98 HRBW |
40 | 2150 | 1177 | 73 | 503 | 139 | 958 | 38 | 98 HRBW |
50 | 2150 | 1177 | 72 | 496 | 138 | 951 | 39 | 98 HRBW |
10 | 2250 | 1232 | 52 | 359 | 125 | 862 | 47 | 92 HRBW |
20 | 2250 | 1232 | 57 | 393 | 128 | 883 | 45 | 92 HRBW |
30 | 2250 | 1232 | 54 | 372 | 126 | 869 | 48 | 92 HRBW |
40 | 2250 | 1232 | 53 | 365 | 126 | 869 | 47 | 91 HRBW |
50 | 2250 | 1232 | 55 | 379 | 128 | 883 | 46 | 89 HRBW |
*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”
Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES® 625 Sheet
Cold-work | Heat Treatment* Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | Hardness | |||
---|---|---|---|---|---|---|---|---|
% | °F | °C | ksi | MPa | ksi | MPa | % | HR BW/C |
No Cold-work | No Heat Treatment | 70 | 483 | 133 | 917 | 46 | 97 HRBW | |
10 | No Heat Treatment | 113 | 779 | 151 | 1041 | 30 | 32 HRC | |
20 | No Heat Treatment | 140 | 965 | 169 | 1165 | 16 | 37 HRC | |
30 | No Heat Treatment | 162 | 1117 | 191 | 1317 | 11 | 40 HRC | |
40 | No Heat Treatment | 178 | 1227 | 209 | 1441 | 8 | 42 HRC | |
50 | No Heat Treatment | 184 | 1269 | 223 | 1538 | 5 | 45 HRC | |
10 | 1850 | 1010 | 63 | 434 | 134 | 924 | 46 | NA |
20 | 1850 | 1010 | 71 | 490 | 138 | 951 | 44 | NA |
30 | 1850 | 1010 | 78 | 538 | 141 | 972 | 44 | NA |
40 | 1850 | 1010 | 82 | 565 | 141 | 972 | 42 | NA |
50 | 1850 | 1010 | 82 | 565 | 141 | 972 | 42 | NA |
10 | 1950 | 1066 | 61 | 421 | 133 | 917 | 46 | NA |
20 | 1950 | 1066 | 71 | 490 | 137 | 945 | 45 | NA |
30 | 1950 | 1066 | 77 | 531 | 140 | 965 | 44 | NA |
40 | 1950 | 1066 | 83 | 572 | 142 | 979 | 42 | NA |
50 | 1950 | 1066 | 82 | 565 | 141 | 972 | 42 | NA |
10 | 2050 | 1121 | 58 | 400 | 128 | 883 | 50 | NA |
20 | 2050 | 1121 | 67 | 462 | 135 | 931 | 46 | NA |
30 | 2050 | 1121 | 58 | 400 | 127 | 876 | 52 | NA |
40 | 2050 | 1121 | 72 | 496 | 137 | 945 | 44 | NA |
50 | 2050 | 1121 | 61 | 421 | 130 | 896 | 50 | NA |
10 | 2150 | 1177 | 52 | 359 | 122 | 841 | 55 | NA |
20 | 2150 | 1177 | 54 | 372 | 124 | 855 | 55 | NA |
30 | 2150 | 1177 | 53 | 365 | 122 | 841 | 56 | NA |
40 | 2150 | 1177 | 52 | 359 | 122 | 841 | 55 | NA |
50 | 2150 | 1177 | 51 | 352 | 119 | 820 | 58 | NA |
*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
NA=Not Available
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardess Rockwell “C”
Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HAYNES HR-120® Sheet
Cold-work | Heat-treatment* Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | Hardness | |||
---|---|---|---|---|---|---|---|---|
% | °F | °C | ksi | MPa | ksi | MPa | % | HR BW/C |
No Cold-work | No Heat Treatment | 60 | 414 | 113 | 779 | 39 | 93 HRBW | |
10 | No Heat Treatment | 103 | 710 | 126 | 869 | 26 | 27 HRC | |
20 | No Heat Treatment | 129 | 889 | 144 | 993 | 11 | 32 HRC | |
30 | No Heat Treatment | 143 | 986 | 157 | 1082 | 6 | 34 HRC | |
40 | No Heat Treatment | 159 | 1096 | 179 | 1234 | 6 | 35 HRC | |
50 | No Heat Treatment | 166 | 1145 | 186 | 1282 | 5 | 36 HRC | |
10 | 1950 | 1066 | 52 | 359 | 109 | 752 | 38 | 89 HRBW |
20 | 1950 | 1066 | 55 | 379 | 111 | 765 | 38 | 92 HRBW |
30 | 1950 | 1066 | 60 | 414 | 115 | 793 | 38 | 93 HRBW |
40 | 1950 | 1066 | 65 | 448 | 117 | 807 | 37 | 93 HRBW |
50 | 1950 | 1066 | 67 | 462 | 118 | 814 | 34 | 93 HRBW |
10 | 2050 | 1121 | 49 | 338 | 108 | 745 | 47 | 88 HRBW |
20 | 2050 | 1121 | 53 | 365 | 117 | 807 | 41 | 90 HRBW |
30 | 2050 | 1121 | 55 | 379 | 112 | 772 | 40 | 91 HRBW |
40 | 2050 | 1121 | 58 | 400 | 114 | 786 | 37 | 91 HRBW |
50 | 2050 | 1121 | 59 | 407 | 114 | 786 | 37 | 89 HRBW |
10 | 2150 | 1177 | 49 | 338 | 109 | 752 | 43 | 86 HRBW |
20 | 2150 | 1177 | 50 | 345 | 109 | 752 | 42 | 87 HRBW |
30 | 2150 | 1177 | 51 | 352 | 110 | 758 | 43 | 88 HRBW |
40 | 2150 | 1177 | 50 | 345 | 111 | 765 | 38 | 86 HRBW |
50 | 2150 | 1177 | 50 | 345 | 110 | 758 | 39 | 82 HRBW |
10 | 2250 | 1232 | 46 | 317 | 106 | 731 | 46 | 84 HRBW |
20 | 2250 | 1232 | 44 | 303 | 104 | 717 | 47 | 80 HRBW |
30 | 2250 | 1232 | 44 | 303 | 103 | 710 | 48 | 80 HRBW |
40 | 2250 | 1232 | 44 | 303 | 104 | 717 | 45 | 81 HRBW |
50 | 2250 | 1232 | 44 | 303 | 104 | 717 | 43 | 83 HRBW |
*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”
Effects of Cold-work and Heat Treatment Temperature on the Room Temperature Mechanical Properties of HASTELLOY® X Sheet
Cold-work | Heat Treatment* Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | Hardness | |||
---|---|---|---|---|---|---|---|---|
% | °F | °C | ksi | MPa | ksi | MPa | % | HR BW/C |
No Cold-work | No Heat Treatment | 57 | 393 | 114 | 786 | 46 | 89 HRBW | |
10 | No Heat Treatment | 96 | 662 | 129 | 889 | 29 | 25 HRC | |
20 | No Heat Treatment | 122 | 841 | 147 | 1014 | 15 | 31 HRC | |
30 | No Heat Treatment | 142 | 979 | 169 | 1165 | 10 | 35 HRC | |
40 | No Heat Treatment | 159 | 1096 | 186 | 1282 | 8 | 37 HRC | |
50 | No Heat Treatment | 171 | 1179 | 200 | 1379 | 7 | 39 HRC | |
10 | 1850 | 1010 | 76 | 524 | 125 | 862 | 32 | 98 HRBW |
20 | 1850 | 1010 | 91 | 627 | 132 | 910 | 27 | 23 HRC |
30 | 1850 | 1010 | 87 | 600 | 135 | 931 | 28 | 99 HRBW |
40 | 1850 | 1010 | 77 | 531 | 133 | 917 | 32 | 98 HRBW |
50 | 1850 | 1010 | 81 | 558 | 135 | 931 | 33 | 99 HRBW |
10 | 1950 | 1066 | 74 | 510 | 122 | 841 | 34 | 93 HRBW |
20 | 1950 | 1066 | 66 | 455 | 124 | 855 | 35 | 96 HRBW |
30 | 1950 | 1066 | 63 | 434 | 126 | 869 | 36 | 96 HRBW |
40 | 1950 | 1066 | 70 | 483 | 129 | 889 | 35 | 96 HRBW |
50 | 1950 | 1066 | 74 | 510 | 129 | 889 | 34 | 97 HRBW |
10 | 2050 | 1121 | 53 | 365 | 119 | 820 | 42 | 89 HRBW |
20 | 2050 | 1121 | 56 | 386 | 121 | 834 | 40 | 91 HRBW |
30 | 2050 | 1121 | 61 | 421 | 123 | 848 | 39 | 94 HRBW |
40 | 2050 | 1121 | 65 | 448 | 125 | 862 | 37 | 94 HRBW |
50 | 2050 | 1121 | 67 | 462 | 125 | 862 | 38 | 94 HRBW |
10 | 2150 | 1177 | 45 | 310 | 109 | 752 | 49 | 94 HRBW |
20 | 2150 | 1177 | 47 | 324 | 111 | 765 | 47 | 87 HRBW |
30 | 2150 | 1177 | 49 | 338 | 113 | 779 | 46 | 86 HRBW |
40 | 2150 | 1177 | 46 | 317 | 110 | 758 | 48 | 85 HRBW |
50 | 2150 | 1177 | 46 | 317 | 110 | 758 | 48 | 84 HRBW |
*5 Minutes Duration + Rapid Air Cool
Tensile Results are Averages of 2 or More Tests
HRBW = Hardness Rockwell “B”, Tungsten Indentor
HRC = Hardness Rockwell “C”
Age-hardening Treatments for Age-hardenable Alloys
Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Alloy | No. of Steps | Treatment |
---|---|---|
C-22HS® | 2 | 16 hours at 1300°F (704°C), furnace cool to 1125°F (607°C),hold at 1125°F for 32 hours, air cool |
242® | 1 | 48 hours* at 1200°F (649°C), air cool |
244® | 2 | 16 hours at 1400°F (760°C), furnace cool to 1200°F (649°C),hold at 1200°F for 32 hours, air cool |
263 | 1 | 8 hours at 1472°F (800°C), air cool |
282® | 2 | 2 hours at 1850°F (1010°C), rapid air cool or air cool,followed by 8 hours at 1450°F (788°C), air cool |
718 | 2 | 8 hours at 1325°F (718°C), furnace cool to 1150°F (621°C),hold at 1150°F for 8 hours, air cool |
R-41 | 1 | 16 hours at 1400°F (760°C), air cool |
WASPALOY | 3 | 2 hours at 1825°F (996°C), air cool,followed by 4 hours at 1550°F (843°C), air cool,followed by 16 hours at 1400°F (760°C), air cool |
X-750 | 2 | 8 hours at 1350°F (732°C), furnace cool to 1150°F (621°C),hold at 1150°F for 8 hours, air cool |
*Minimum
To harden/strengthen those materials capable of age hardening, the following treatments are usually applied, assuming the starting material is in the solution-annealed condition. Alternate hardening/strengthening treatments are possible for some of these alloys, depending upon the intended applications and the required strength levels. Please contact Haynes International for details.
Heating and Cooling Rates
Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
Heating and cooling of the HAYNES® and HASTELLOY® alloys should generally be as rapid as possible. This is to minimize the precipitation of second phase particles (notably carbides, in the case of the high-temperature alloys) in their microstructures at intermediate temperatures. Rapid heating also preserves stored energy from cold- or warm-work, which can be important to re-crystallization and/or grain growth at the annealing temperature. Indeed, slow heating can result in a finer than desirable grain size, particularly in thin-section components, given limited time at the annealing temperature.
Rapid cooling after solution-annealing is critical, again to prevent the precipitation of second phases, particularly in the microstructural grain boundaries in the approximate temperature range 1000°F to 1800°F (538°C to 982°C). Where practical, and where it is unlikely to cause distortion, a water quench is preferred. It will be noted that cooling from age-hardening treatments (in the case of the age-hardenable, high-temperature alloy components) usually involves air cooling.
The sensitivity of individual alloys to slow cooling varies, but as an example of the effect of cooling rate upon properties, the following table shows the creep life of HAYNES® 188 alloy as a function of the cooling process.
Effect of Cooling Rate upon the Creep Life of HAYNES® 188 Sheet
Cooling Process after Solution-annealing at 2150°F (1177°C) | Time to 0.5% Creep for1600°F/7 ksi (871°C/48 MPa) Test |
---|---|
Water Quench | 148 h |
Air Cool | 97 h |
Furnace Cool to 1200°F (649°C), then Air Cool | 48 h |
Holding Time
The times at temperature required for annealing are governed by the need to ensure that all metallurgical reactions are complete, uniformly and throughout the component. As mentioned earlier, the general rules for holding time are at least 30 minutes per inch of thickness in the case of massive workpieces and components, and 10 to 30 minutes (once the entire piece is uniformly at the required annealing temperature) for less massive workpieces and components, depending upon section thickness. Extremely long holding times (such as overnight) are not recommended, since they can be harmful to alloy microstructures and properties.
For continuous annealing of strip or wire, several minutes at temperature will usually suffice.
Time in the furnace will depend on the furnace type and capacity, and the work-piece/component thickness and geometry. To determine when the entire work-piece has reached the required annealing temperature, measurements should be taken using thermocouples attached to the work-piece, where possible.
Use of a Protective Atmosphere
Most of the HAYNES® and HASTELLOY® alloys can be annealed in oxidizing environments, but will form adherent oxide scales which should normally be removed prior to further processing. For details on scale removal, please refer to the the section on Descaling and Pickling.
Some HAYNES® and HASTELLOY® alloys contain low chromium contents, and require annealing in neutral or slightly reducing atmospheres.
When a bright finish (free from oxide scales) is required, a protective atmosphere, such as low dew point hydrogen, is necessary. Atmospheres of argon and helium have been used, although pronounced tinting is possible with these alternate gases, due to oxygen or water vapor contamination. Annealing in nitrogen or cracked ammonia is not usually recommended, but may be acceptable in certain cases.
Vacuum annealing is generally acceptable, but again some tinting is possible, depending on the vacuum pressure and temperature. Selection of the gas used for forced gas cooling is important: Helium is normally preferred, followed by argon and nitrogen (for some alloys).
Selection of Heat-Treating Equipment
Most types of industrial furnace are suitable for heat treating the HAYNES® and HASTELLOY® alloys. However, induction heating is not normally recommended, due to inadequate control of the temperature and lack of uniform heating. Heating by torches, welding equipment, and the like is unacceptable. Flame impingement of any type during heat treatment should be avoided.
Machining
Recommended Tools and Machining Parameters Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Be aware that the cobalt-base alloys in these categories (25 and 188) can require different feeds and speeds (as noted in the table) than the nickel- and iron-based alloys.
Operations | Tool Types | Tool Geometryand Set-Up | Speed | Feed | Depth of Cut | Lubricant |
---|---|---|---|---|---|---|
- | - | - | surface ft./min* | in** | in** | - |
Roughing with severe interruptions; Turning or Facing | Carbide: C-2 or C-3grade |
Negative rake square or trigon insert, 45° SCEA1, 1/16 in nose radius Tool holder: 5° negative back rake, 5° negative side rake |
30-50 | 0.004-0.008per revolution | 0.15 |
Dry2, oil3, or water-based4,5 |
Normal roughing; Turning or Facing | As above | As above |
90 (80 for cobalt alloys)6 |
0.010per revolution | <0.15 | Dry, oil, or water-based |
Finishing; Turning or Facing | As above |
Positive rake square or trigon insert, if possible, 45° SCEA1, 1/32 in nose radius Tool holder: 5° positive back rake, 5° positive side rake |
95-110 (90 for cobalt alloys) | 0.005-0.007 per revolution | 0.04 | Dry or water-based |
Rough Boring | As Above | If insert-type boring bar, use standard positive rake tools with largest possible SCEA and 1/16 in nose radius. If brazed tool bar, grind 0° back rake, 10° positive side rake, 1/32 in nose radius and largest possible SCEA | 70 (60 for cobalt alloys) | 0.005-0.008 per revolution | 0.125 | Dry, oil, or water-based |
Finish Boring | As Above | Use standard positive rake tools on insert-type bars. Grind brazed bars as for finish turning, except back rake may be best at 0° | 95-110 (90 for cobalt alloys) | 0.002-0.004 per revolution | 0.04 | Water-based |
High Speed Steel: M-2, M-7, or M-40 series7 |
Radial and axial rake0° to 10° positive, 45° corner angle, 10° relief angle | 20-30 (20-25 for cobalt alloys) | 0.003-0.005 per tooth | - | Oil or water-based | |
Carbide: C-2 grade (marginal performance) | Use positive axial and radial rake, 45° corner angle, 10° relief angle | 50-60 (35-40 for cobalt alloys) | 0.005-0.008per tooth (0.005 per tooth for cobalt alloys) | - | Oil or water-based | |
End Milling | High Speed Steel: M-40 series or T-15 | If possible, use short mills with four or more flutes for rigidity | 20-25 (15-20 for cobalt alloys) | Feed per tooth: ¼ in dia. 0.002 ½ in dia. 0.002 ¾ in dia. 0.0031 in dia. 0.004(cobalt alloys: ¼ in dia. 0.001 ½ in dia. 0.0015 ¾ in dia. 0.0021 in dia. 0.003) | - | Oil or water-based |
Carbide: C-2 grade | Use sharp tools with 4 or more flutes and variable lead, if possible | Carbide: C-2 grade (marginal performance) | Use positive axial and radial rake, 45° corner angle, 10° relief angle | - | Oil or water-based | |
Drilling | High Speed Steel: M-33, M-40 series, or T-15 | Use short, heavy-web drills with 135° crank shaft point; thinning of web at point may reduce thrust and aid chip control | 10-15 (7-10 for cobalt alloys) Maximum of 200 rpm for¼ in dia. drills or smaller | Feed per rev.: ⅛ in dia. 0.001 ¼ in dia. 0.002 ½ in dia. 0.003 ¾ in dia. 0.0051 in dia. 0.007(same for cobalt alloys) | - | Oil or water-based Use coolant feed drills if possible |
Carbide :C-2 grade | Not recommended, but tipped drills may be successful on rigid set-ups if depth is not great. The web must be thinned to reduce thrust; use 135° included angle on point Gun drill can be used. | 50 (40 for cobalt alloys) | As above | - | Oil or water-based Coolant-fed, carbide-tipped drills may be economical in some set-ups | |
Reaming | High Speed Steel: M-33, M-40 series, or T-15 | Use 45° corner angle, narrow primary land, and 10° relief angle | 10-15 (8 for cobalt alloys) | Feed per rev.: ½ in dia. 0.0032 in dia. 0.008 (same for cobalt alloys) | - | Oil or water-based |
Carbide: C-2 or C-3grade | Tipped reamers recommended; solid reamers require very good set-up. Tool geometry same as above. | 40 (20 for cobalt alloys) | As above | - | Oil or water-based | |
Tapping | High Speed Steel: M-1, M-7, or M-10 | Use two flute, spiral point, plug tap 0° to 10° hook angles. Nitrided surface may be helpful by increasing wear resistance, but may result in chipping orbreakage Tap drill for 60-65% thread if possible, to increase tool life. | 7 (same for cobalt alloys) | - | - | Use best possible tapping compound; sulfo-chlorinated oil-base preferred |
Carbide: not recommended | - | - | - | - | - | |
Electrical Discharge Machining | HAYNES® and HASTELLOY® alloys can be readily cut using any conventional Electrical discharge machining (EDM) system, or by wire EDM |
General note: Use high pressure coolant systems and through the tool coolant, when possible.
*To convert to surface m/min, multiply by 0.305
**To convert from in to mm, multiply by 25.4
1SCEA = side cutting edge angle, or lead angle of the tool
2At any point where dry cutting is recommended, an air jet directed at the tool may provide a substantial increase in tool life
3Oil coolants should be premium quality, sulfo-chlorinated oils, with extreme pressure additives; a viscosity of 50 to 125 SSU at 100°F (38°C) is standard
4Water-based coolants should consist of a 15:1 mixture of water and either a premium quality, sulfo-chlorinated, water-soluble oil or a chemical emulsion, with extreme pressure additives
5Water-based coolants may cause chipping or rapid failure of carbide tools in interrupted cuts
6Depending upon the rigidity of the set-up
7M-40 series high speed steels include M-41 through M-46 at time of writing; others may be added and should be equally suitable
Applicable to:
Wear & Corrosion-resistant Alloy
ULTIMET® alloy can be successfully turned, drilled, and milled if appropriate tooling and parameters are employed. However, the alloy possesses high strength and work hardens rapidly. Machining guidelines specific to ULTIMET® alloy are as follows:
Turning (ULTIMET® alloy)
Carbide (not high speed steel) tools are recommended.
Surface speed: 60-70 surface ft./min (0.30-0.35 m/s).
Feed rate: 0.005-0.010 in (0.13-0.25 mm).
Depth of cut for roughing: 0.05-0.10 in (1.3-2.5 mm).
Depth of cut for finishing: 0.010-0.015 in (0.25-0.38 mm).
Drilling (ULTIMET® alloy)
Carbide tipped or high speed steel drills are recommended.
Surface speed: 30-35 surface ft./min (0.15-0.18 m/s) for carbide tipped drills; 8-10 surface ft/min (0.04-0.05 m/s) for high speed steel drills.
Feed rate: 0.004 in (0.1 mm) per revolution for 0.25 in (6.4 mm) diameter and greater.
135° included angle on point.
Milling (ULTIMET® alloy)
Carbide (not high speed steel) end mills are recommended.
Surface speed: 25-30 surface ft/min (0.13-0.15 m/s).
Feed per tooth: 0.002 in (0.05 mm) for cutter diameters below 0.75 in (19 mm); 0.003 in (0.08 mm) for cutter diameters above 0.75 in (19 mm).
Grinding
Recommended Wheels and Coolants Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Type of Grinding | Wheels* | Manufacturer | Type of Work | Coolant |
---|---|---|---|---|
Cylinder Grinding | ||||
Straight or tapered O.D. | 53A80-J8V127 | Norton | Sharp corners andfine finish | Heavy-duty soluble coolant25: 1 mix CASTROL 653 |
Form work, single wheel section method | 38A60-J8-VBE | Norton | Removing stock, sharp corner work, straight radius work | Dry |
Form work, crush-roll method | 53A220-L9VB | Norton | Precision forms, radius | Straight oil |
Centerless | 53A80-J8VCN | Norton | Thin-walled material, solid or heavy-walled material | Heavy-duty soluble coolant 25:1 mix CASTROL 653 |
Internal Grinding | ||||
Straight or tapered | 23A54-L8VBE | Norton | Small holes, medium-sized holes, large holes, small counter-bores | Heavy-duty soluble coolant 25:1 mix > CASTROL 709 |
Surface Grinding | ||||
Straight wheel | 32A46-H8VBE38A46-I-V | Norton | - | Dry or any heavy-dutysoluble coolant 25:1 mix CASTROL 653 |
Double-opposed disk type | 87A46-G12-BV87A46-J11-BW | Gardner | Through-feed work, Ferris wheel work, thin work | Heavy-duty soluble coolant 10:1 mix CASTROL 653 |
Cylinder or segmental-type | 32A46-F12VBE | Norton | Thin work, bevels, and close-tolerance work | Sal-soda in water CASTROL 653 |
Single wheel section method | 32A46-F12VBEP | Norton | Profile work | Dry |
Thread Grinding | ||||
External threads | A100-T9BH | Norton | - | VANTOL 5299-Mor equivalent |
Honing | ||||
Internal | C120-E12-V32C220-K4VEJ45-J57 | Bay State Carborundum Sunnen | - | VANTOL 5299-Cor equivalent |
Rough Grinding | ||||
Cut-off (wet) | 86A461-LB25W | Norton | - | CASTROL 653 |
Cut-off (dry) | 4NZA24-TB65N | Norton | - | Dry |
Snagging | 4ZF1634-Q5B38 | Norton | - | Dry |
*The wheels indicated have been optimized for speeds between 6000 and 6500 surface ft./min
Descaling and Pickling
Applicable to:
Corrosion-resistant Alloys
High-temperature Alloys
Wear & Corrosion-resistant Alloy
As a result of their inherent resistance to corrosion, the HAYNES® and HASTELLOY® alloys are generally inert to cold acid pickling solutions. Also, the oxide films that form on these alloys during heat treatment are more adherent than those that form on the stainless steels.
The most effective descaling methods for the HAYNES® and HASTELLOY® alloys are immersion in molten caustic baths, followed by acid pickling at elevated temperatures.
Three descaling methods have been used successfully with the HAYNES® and HASTELLOY® alloys, namely:
- The VIRGO descaling salt bath process.
- The sodium hydride reducing salt bath process.
- The DGS oxidizing salt bath process.
The procedures associated with these methods are shown in the table below.
Descaling and Pickling Procedures
- | VIRGO Descaling Salt Bath | Sodium Hydride Reducing Salt Bath | DGS Oxidizing Salt Bath |
---|---|---|---|
Descaling Bath | VIRGO Salt | Sodium Hydride | DGS Salt |
Bath Temperature | 970°F (521°C) | 750°F-800°F (399°C-427°C) | 850°F-950°F (454°C-510°C) |
Descaling Time | 1 to 3 minutes | 15 minutes | 2 to 10 minutes |
Water Rinse Time | 1 to 2 minutes | 1 to 2 minutes | 1 to 5 minutes |
Pickling Step 1 | 15-17% Sulfuric Acid+ 0.5-1% Hydrochloric Acid at 165°F (74°C) for 3 minutes* | 4-6% Potassium Permanganate+ 1-2% Sodium Hydroxide at 135°F-155°F (57°C-68°C) for 15 minutes* | 15-25% Nitric Acid+ 3-5% Hydrofluoric Acid at 130°F-150°F (54°C-66°C) for 10 to 20 minutes |
Pickling Step 2 | 7-8% Nitric Acid+ 3-4% Hydrofluoric Acid at 125°F-160°F (52°C-71°C) for 25 minutes | 8-12% Nitric Acid+ 2-3% Hydrofluoric Acid at 125°F-160°F (52°C-71°C) for 15 minutes | No Second Step |
Final Water Rinse | 3 minutes or Steam Spray | Dip | Dip and Steam Spray |
Descaling Bath | VIRGO Salt | Sodium Hydride | DGS Salt |
Bath Temperature | 970°F (521°C) | 750°F-800°F (399°C-427°C) | 850°F-950°F (454°C-510°C) |
*Followed by a water rinse
Sand, shot, or vapor blasting are acceptable for removing scales, under certain conditions. The blasting materials should be such that they provide a rapid cutting action, rather than smearing the surface. Also, sand should not be re-used, especially if contaminated with iron. After blasting, it is desirable to pickle the work-piece in acid, to remove any embedded iron or other impurities.
Extreme care should be taken when blasting thin-sectioned components with sand, because of the dangers of distortion and/or embedding sand or scale in the metal surface. Sand blasting also tends to work harden the surfaces, which may cause subsequent forming problems for certain alloys.