HAYNES® 556® alloy for Industrial Heating Applications Tech Brief

 

For Industrial Heating & Heat Training Applications

For high-strength heat-treating furnace fans, brazing fixtures, and other critical components that require resistance to high-temperature aggressive environments coupled with excellent strength and fabricability, the first choice is HAYNES® 556® alloy. 556® alloy has the best combination of carburization resistance, strength, and oxidation-resistance for high speed carburizing furnace fan applications to 2000ºF. It is also well considered for heavy duty chains, baskets and T/C protection tubes in such facilities. In high temperature brazing furnace applications, 556® alloy provides the same excellent strength coupled with resistance to fluxing compounds, salts, and other corrosive species. For nested tables, vacuum brazing fixtures, and baskets, and hardware of all types, 556® alloy provides premier capabilities compared with traditional stainless steels and industrial heating alloys.

Resistance to Corrosion in Molten 100% NaCl for 100 Hours at 1550°F
Alloy Average Metal Affected
Mils
556® 2.6
X 3.8
310 4.2
800H 4.3
625 4.4
RA330® 4.6
RA333® 7.5
600 7.7

Nominal Composition

Iron Balance
Nickel 20
Cobalt 18
Chromium 22
Molybdenum 3
Tungsten 2.5
Tantalum 0.6
Nitrogen 0.2
Silicon 0.4
Manganese 1
Aluminum 0.2
Carbon 0.1
Lanthanum 0.02
Zirconium 0.02

Typical Tensile Properties, Plate

Test Temperature 0.2% Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
RT RT 55 375 116 805 51
1000 540 31 210 90 625 60
1200 650 31 210 83 575 57
1400 760 29 200 69 470 53
1600 870 28 190 49 340 69
1800 980 19 130 31 210 84
2000 1095 9 60 16 110 95

Typical Rupture Properties, Plate

Test Temperature Typical Rupture Properties: Stress Required to Produce Rupture in Hours Shown
100 h 1,000 h 10,000 h
°F °C ksi MPa ksi MPa ksi MPa
1400 760 25.0 172 17.5 121 11.9 98
1500 815 17.0 117 11.8 81 7.8 43
1600 870 11.5 79 7.5 52 4.9 34
1700 915 7.6 52 4.8 33 3.0 21
1800 980 4.8 33 3.0 21 1.9 13

Typical Room Temperature Physical Properties

Physical Property British Units Metric Units
Density
0.297 lb/in3
8.23 g/cm3
Electrical Resistivity 37.5 µohm-in 95.2 µohm-cm
Modulus of Elasticity
29.7 x 106 psi
206 GPA
Thermal Conductivity
77 Btu-in/ft2-h-°F
11.1 W/m-°C
Specific Heat 0.111 Btu/lb-°F 464 J/Kg-°C

Environmental Resistance

Oxidation in Air – Excellent at 2000°F (1095°C)

Sulfidation – Second only to Co-base alloys

Molten Chloride Salts – Equal to alloy X

Chlorination – Very good to 1650°F (900°C)

Carburization – Equal to alloy 800H

Molten Zinc – Best Available

Product Description

HAYNES® 556® alloy is an iron-nickel-chromium-cobalt alloy that combines effective resistance to sulfidizing, carburizing, and chlorine-bearing environments at high temperatures with good oxidation resistance, fabricability, and excellent high-temperature strength. It has also been found to resist corrosion by molten chloride salts and molten zinc.

HAYNES® 556® alloy is highly useful for service at elevated temperature in moderately to severely corrosive environments. Applications include tubing and structural members in waste heat recuperators, super heaters, and internals in municipal and chemical waste incinerators; power plant burner buckets, cair nozzles, and fluidized bed combustor heat exchangers and internals; high speed furnace fans, galvanizing bath hardware and brazing fixtures; and high-temperature rotary calciners and kilns. There are also additional uses in the chemical petrochemical process and pump and paper industries.