It is superior in resistance stress corrosion crack characteristic and manufacturing method null of the Cr-Ni stainless steel sheet where surface quality

摘要

PURPOSE:To obtain a steel sheet excellent in stress corrosion cracking resistance and surface quality by means of direct cold rolling by continuously casting a molten steel in which delta-Fecal is specified into a strip-like slab, controlling cooling, and subjecting the above slab to cold rolling, to annealing, and to temper rolling in which elongation is controlled. CONSTITUTION:A molten steel having a composition which consists of, by weight, =0.1% C, =4% Si, =4% Mn, =0.03% P, =0.006% S, 16-30% Cr, 3-16% Ni, =3% Cu, =0.3% N, and the balance essentially Fe with inevitable impurities and in which delta-Fecal(%) determined by an equation is regulated to 6-50% is continuously cast into a strip-like slab of =10mm thickness. After solidification, the above cast slab is cooled from a temp. as high as possible down to 1200 deg.C at =50 deg.C/sec average cooling rate to undergo the prevention of recuperation. Subsequently, the above slab is cooled from 1200 down to 600 deg.C at =10 deg.C/sec cooling rate, coiled, descaled, and cold-rolled. After annealing, acid pickling, etc., the resulting sheet is subjected to temper rolling in which elongation is controlled to 0.1-2.5%.