Brief description of the drawings for the manufacture of the ferritic stainless steel has two phases, having a capacity high to the forming and containing 17 chromium

摘要

Commercially available ferritic stainless steel strip about 4 mms. thick and containing by weight 0.017% carbon, 0.19% silicon, 0.19% manganese, 0.017% phosphorous, 0.002% sulphur,, 17.61% chromium, 0.13% nickel, 0.035% nitrogen, 0.04% copper and the rest iron is treated to render it easier to shape. The strip is heated in a muffle furnace at 1050-1150 K, corresponding to a single phase structure on a diagram plotting temperature against %Cr, then scoured and cold-rolled to a thickness of 0.7 mms. in two stages, involving respective thickness reductions of 55-65% and 65-75%, with scouring and annealing at 1100-1150 K for 2-4 mins. between the stages. Finally the strip is heated to 1175-1275 K, corresponding to a two-phase structure, for 0.5-1.5 mins., scoured and quenched in air or water.