COLD ROLLED MULTILAYER STEEL SHEET HAVING SURFACE LAYER COMPOSED OF FERRITIC STAINLESS STEEL AND EXCELLENT IN CORROSION RESISTANCE AND DEEP DRAWABILITY, AND ITS PRODUCTION

摘要

PURPOSE: To improve corrosion resistance, workability, and deep drawability by specifying the composition of the inner layer part, the proportion of the surface layer parts composed of ferritic stainless steel based on the whole plate thickness, and cold rolling conditions and annealing conditions, respectively. ;CONSTITUTION: A multilayer cast slab where the surface layer parts are composed of ferritic stainless steel and the inner layer part has a composition consisting of, by weight, 0.0002-0.0150% C, 0.005-0.0150% N, Si and P and Al by the amounts satisfying the conditions in inequality I, further Ti and/or Nb by the amounts satisfying the conditions in inequality II, and the balance Fe with inevitable impurities is cast. The proportion of the surface layer parts to the whole plate thickness is regulated to 2-30% per side. This steel slab is hot-rolled and then cold-rolled at 40-90% reduction of area, followed by annealing at a temp. between the recrystallization temp. and 1150°C. This cold rolled multilayer steel sheet can be used as a material for a surface treated steel sheet to be plated with zinc, tin, chromium, aluminum, etc.;COPYRIGHT: (C)1993,JPO&Japio