Hardening of austenitic chromium-nickel steels by working at sub-zero temperatures

摘要

In a process of heat-treating austenitic chromium nickel steels, the steels are cooled to between minus 50 DEG F and the boiling temperature of nitrogen, mechanically worked at that temperature and finally aged at 500-1000 DEG F. The mechanical working may be forging or shot-blasting. Steels of the 18 per cent Cr-8 per cent Ni type which may contain up to 4 per cent Mo, up to 0.5 per cent N, and Nb or Ti in amount equal to 10 times the carbon content, may be used. The treatment is stated to give a final hardness of 450-550 Vickers.