SECORP designation (UNS NO.)
A nickel-chromium-iron alloy with moderate strength and good resistance to oxidation and carbonization at elevated temperatures. The alloy does not form the embrittling sigma phase on long term exposure to 1200°F (649°C).
 
Tubes for steam methane reformers and ethylene pyrolusis units. Furnace tube for diphenyl, vinyl chloride monimer and acetis anhydride. Appliance heater tubing, heat treat fixtures. Standard material in nuclear and fossil-fired power plants, for steam generators and feedwater heaters.