High-temperature Alloys for Incineration Applications

 

Heat-Resistant Alloys for Incinerator Components

Haynes International dates back to 1912 in Kokomo, Indiana where Elwood Haynes developed the first cobalt-chromium-tungsten metal-cutting tools. These remained the premium tool material for many years. They provided Haynes a natural entry into the high-temperature alloy field at mid-century with the advent of the jet aircraft engine. With the successive development of MULTIMET® alloy, HASTELLOY® X alloy, HAYNES® 188 alloy, HAYNES® 230® alloy and the even newer alloys described in this booklet, Haynes has remained at the forefront of heat-resistant alloy technology for nearly half a century. Most recently, Haynes has focused on special high-temperature alloys for non-aerospace applications. A primary research area is the development of high-temperature alloys to meet the needs of the growing waste incineration industry.

Nominal Composition

HR-160®

Iron 2
Cobalt 29
Chromium 28
Molybdenum
Tungsten
Nitrogen Balance
Tantalum
Titanium 0.45
Nitrogen
Silicon 2.75
Manganese 0.5
Aluminum
Carbon 0.05
Niobium*
Boron
Lanthanum
Zirconium

*Also known as Columbium

556®

Iron Balance
Cobalt 18
Chromium 22
Molybdenum 3
Tungsten 2.5
Nitrogen 20
Tantalum 0.6
Titanium
Nitrogen 0.2
Silicon 0.4
Manganese 1.0
Aluminum 0.2
Carbon 0.10
Niobium*
Boron
Lanthanum 0.02
Zirconium 0.02

HR-120®

Iron Balance
Cobalt 3 max.
Chromium 25
Molybdenum 2.5 max.
Tungsten 2.5 max.
Nitrogen 37
Tantalum
Titanium 0.1
Nitrogen 0.2
Silicon 0.6
Manganese 0.7
Aluminum 0.1
Carbon 0.05
Niobium* 0.7
Boron 0.004
Lanthanum
Zirconium

HR-160® alloy

The premier alloy for waste-incineration service is the recently developed HR-160® alloy. This Ni-Co-Cr-Si alloy was developed to offer outstanding resistance to severely sulfidizing environments and many others including tl10se wl1icl1 contain chlorine or chlorides. It offers a cost-effective alternative to lower-cost/ lower grade alloys by increasing component life and decreasing operating costs.

556® alloy

This versatile Fe-Ni-Co-Cr alloy serves well in a number of high-temperature corrosive environments that are sulfidizing, oxidizing, carburizing or chlorine-bearing. This, plus the alloy’s outstanding high strength make it particularly well suited for service in incinerator environments.

HR-120® alloy

HR-120® alloy is another of Haynes’ newest non-aerospace alloys. It is a nitrogen-strengthened Fe-Ni-Cr alloy with better mechanical properties, oxidation resistance and hot workability than 800 series and 330 alloys. Tile carefully controlled nitrogen content and control of tile nitrogen-niobium(columbium)-carbon ratio results in the improved properties. A chromium level of 25 percent contributes to good oxidation and environmental resistance and stabilizes the nitrogen.

Physical Properties

Physical Property HR-160®
British Units Metric Units
Density 70°F
0.292 lb/in3
20°C
8.08 g/cm3
Melting Point 2360°F 1295°C
Electrical Resistivity 70°F 43.8 µohm-in 20°C 111.2 µohm-cm
1200°F 48.3 µohm-in 650°C 122.7 µohm-cm
2000°F 49.6 µohm-in 1095°C 126.0 µohm-cm
Thermal Conductivity 800°F
125 Btu-in/ft2-h-°F
425°C 18.3 W/m°C
1600°F
185 Btu-in/ft2-h-°F
870°C 26.8 W/m°C
Mean Coefficient of Thermal Expansion 1200°F 8.6 µin/in. °F 650°C 15.5 μm/m.°C
1400°F 8.9 µin/in.°F 760°C 16.0 μm/m.°C
1600°F 9.2 µin/in.°F 870°C 16.6 μm/m.°C
1800°F 9.5 µin/in.°F 980°C 17.1 μm/m.°C
Dynamic Modulus of Elasticity 70°F
30.6 x 106 psi
20°C 211 GPa

 

Physical Property 556®
British Units Metric Units
Density 70°F
0.297 lb/in3
20°C
8.23 g/cm3
Melting Point 2425°F 1330°C
Electrical Resistivity 70°F 37.5 µohm-in 20°C 95.2 µohm-cm
1200°F 45.7 µohm-in 650°C 116.1 µohm-cm
2000°F 48.6 µohm-in 1095°C 123.4 µohm-cm
Thermal Conductivity 800°F
135 Btu-in/ft2-h-°F
425°C 19.6 W/m°C
1600°F
185 Btu-in/ft2-h-°F
870°C 26.8 W/m°C
Mean Coefficient of Thermal Expansion 1200°F 9.0 µin/in.°F 650°C 16.2 μm/m.°C
1400°F 9.2 µin/in.°F 760°C 16.6 μm/m.°C
1600°F 9.4 µin/in.°F 870°C 16.9 μm/m.°C
1800°F 9.5 µin/in.°F 980°C 17.1 μm/m.°C
Dynamic Modulus of Elasticity 70°F
29.7 x 106 psi
20°C 205 GPa

 

Physical Property HR-120®
British Units Metric Units
Density 70°F
0.291 lb/in3
20°C
8.02 g/cm3
Melting Point 2375°F 1300°C
Electrical Resistivity 70°F 41.4 µohm-in 20°C 105.2 µohm-cm
1200°F 48.2 µohm-in 650°C 122.4 µohm-cm
2000°F 50.3 µohm-in 1095°C 127.8 µohm-cm
Thermal Conductivity 800°F
120 Btu-in/ft2-h-°F
425°C 17.4 W/m°C
1600°F
180 Btu-in/ft2-h-°F
870°C 26.1 W/m°C
Mean Coefficient of Thermal Expansion 1200°F 9.2 µin/in.°F 650°C 16.6 μm/m.°C
1400°F 9.5 µin/in.°F 760°C 17.1 μm/m.°C
1600°F 9.7 µin/in.°F 870°C 17.5 μm/m.°C
1800°F 9.9 µin/in.°F 980°C 17.8 μm/m.°C
Dynamic Modulus of Elasticity 70°F
28.6 x 106 psi
20°C 197 GPa

Tensile Data

HR-160®
Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
70 20 46 317 107 738 73
1600 870 24 165 62 427 104
2000 1095 6 41 10 69 105
556®
Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
70 20 61 420 119 820 47
1600 870 29 200 47 324 53
2000 1095 8 55 15 103 59
HR-120®
Temperature 0.2% Offset Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
70 20 51 352 105 724 48
1600 870 29 200 47 324 36
2000 1095 9 62 14 96 48

Stress-Rupture Strength

HR-160®
Temperature Approximate Stress-Rupture in
°F °C ksi MPa
1400 760 10.5 72
1600 870 5.8 40
1800 980 2.7 19
556®
Temperature Approximate Stress-Rupture in
°F °C ksi MPa
1400 760 17.5 121
1600 870 7.5 52
1800 980 3.0 21
HR-120®
Temperature Approximate Stress-Rupture in
°F °C ksi MPa
1400 760 17.0 117
1600 870 8.0 55
1800 980 3.4 23

Comparative Field and Laboratory Data

The following laboratory data illustrate the excellent resistance of HAYNES®‘ alloys in controlled sulfidizing and chlorine-bearing incinerator environments. This resistance, plus high strength, make the alloys excellent candidates for a number of applications.

Haynes will assist incinerator engineers and operators in selecting materials. A typical analysis may include review of preliminary laboratory test results in an environment similar to that expected in actual service. An actual failed component may be analyzed to establish corrosion mode. A search through Haynes’ extensive database can reveal a potential alloy upgrade (not necessarily an alloy described in this booklet). Additionally, field testing of prime candidates may provide data for a prudent selection.

Laboratory results are sometimes presented in this pictorial format. Here tile comparative sulfidation resistance of HR-160®, 556®, 800H, and 600 alloys arc dramatically shown. The height of each photomicrograph represents original section thickness. All of the samples were exposed to Ar + 5% H1+ 5% CO + 5% CO, + 0.15% H2S at 1600°F (870°c) for 215 hours. Small amounts of dark area (meta/loss) and internal a/lack gives clear indication of the superiority of HR-160® alloy.

Here again. HR-160® (left) alloy shows best (compared to 601, RA330® and 253MA alloys) in tile same environment and temperature as above only for a longer time (500 hours). This is the same type or test rack used in field trial evaluations. Note smooth surface and sharp comers on HR-160® alloy sample.

Chlorine-bearing environments also cause considerable damage to incinerator component. These data for tests in Ar +20% O2 + 0.25% Cl2 show very low metal loss for 556® alloy compared to the other alloys. Test temperature was 1650°F (900°C), 400 hours. While not tested in this environment, HR-160® alloy has excellent field experience in chlorine and chloride bearing environments.

In some applications, sulfidation resistance alone does not suffice in an incinerator since many components are load-bearing. This chart portrays a composite of sulfidation resistance/stress-rupture strength at 1600°F (870°C). HR-160® alloy is “off the chart” in this comparison with other common high-temperature alloys.

Alloy Performance Capacity

HR-160®

Industrial Field Test Performance as Compared to Current Materials Applications
Municipal Waste Incinerators 1800-2000°F, sulfur, chlorides, K, Zn, etc. > 17X better than stainless steels Tulle support, tube shields, dampers, ducts, liners, vortex finders, thermos-wells, etc.
1300-1400°F, sulfur chlorides. K, Zn, Pb. 9X better than 625 Potential application: Co-extruded tubes for super heater and
Industrial Waste Incinerators 1600-1700°F, Sulfur chlorides, K, etc. >20X better than stainless steels Combustion liners, reactors, ducts, dampers, thermo-wells vortex finders, etc.
Hospital Waste Incinerators 1200-1400°F, sulfur chlorides. Zn, etc. > 7X better than 304 and 316 Combustion liners. ducts, dampers, thermos-wells, etc.
Low Level Radioactive Waste Incinerators 1100-1400°F, sulfur chlorides, Zn, P, Pb, etc. 9X better than 310 Combustion liners, ducts, dampers, thermos-wells, etc.


556® alloy was chosen for components of this waste ash handling system operating at 1650°F (900°C). The 556® alloy system more than doubled the life of previously used 309 stainless steel.


Refractory anchors of 309 stainless steel lasted two months in a manure incinerator at 1600°F (870 °C). Various other alloy substitutions did no better. After six months service, a weld overlay of HR-160® alloy exhibited little signs of attack.

A 6-in. NPS bellows, used in a high-temperature waste gas system, demonstrates fabricability of 556® alloy. It was produced by Badger Industries, Inc., Zelienople, PA.

 


Thermocouple protection tubes of both HR-160® and 556® alloys yield dramatic service life extensions compared to 309 and 446 stainless tubes in industrial and hazardous waste incineration systems.


Tilis 75 ft. long retort of HR- 160® alloy operates at temperatures up to 2200°F (1200°C) to remove lead, zinc and cadmium from electric arc furnace effluents. It was fabricated for Zia Technology, Caldwell, TX by The Alloy Engineering Co., Berea, OH.


HR-160® alloy has experienced rapid acceptance as the premier super heater tube shield material. These shields are used in a municipal waste incinerator which suffers from both high-temperature corrosion and fly ash erosion.


Field testing showed HR-160® alloy to be the only suitable alloy for this calciner used to process sulfonated organic material at 1200 to 1960°F (650 to 1050°C).