HAYNES® 556® alloy for High-Speed Furnace Fans Tech Brief
For High-Speed Fans in Carburizing and Industrial Furnaces
Long-lived furnace components can be crucial for cost-effective heat-treatment. Downtime due to furnace fan failures or insufficient fan life costs the heat treater money. How can furnace fan life be extended and reliability increased? By using HAYNES® 556® alloy -that’s how. HAYNES 556 alloy combines outstanding high-temperature strength and long-term resistance to carburization compared to conventional materials. Fans fabricated from 556 alloy are designed to last in excess of ten thousand hours at temperatures up to 2000°F (1093°C). This is due in part to the alloy’s excellent high-temperature creep and stress rupture properties. Because of its outstanding high temperature strength, 556 alloy can be designed thinner than conventional materials. This not only reduces materials costs, but allows for faster furnace heat-up and cool-down cycles. This saves on furnace costs and increases productivity. Can you afford not to consider 556 alloy?
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 | 82 |
1500 | 815 | 17.0 | 117 | 11.8 | 81 | 7.8 | 52 |
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.