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.