Fine grained austenitic stainless steel plate with excellent stress corrosion cracking and workability

摘要

PROBLEM TO BE SOLVED: To provide a fine granular austenitic stainless steel sheet in which a stress-corrosion cracking as a defect is eliminated, and good workability is also obtained by regulating average crystal grain diameter to ≤10 μm in Ni content of ≤8% and the characteristics of the crystal grain boundary.;SOLUTION: The austenitic stainless steel sheet has the steel composition composed of, by mass%, ≤0.05% C, 14-19% Cr, ≤2% Si, ≤4% Mn, 5-8% Ni, ≤4% Cu, ≤0.1% N, and the balance Fe with inevitable impurities, wherein Md=551-462(C+N)-9.2Si-8.1Mn-13.7Cr-29(Ni+Cu)-18.2Mo is in the range of -20 to 40; the average crystal diameter is ≤10 μm; and the ratio of a large bevel grain boundary of ≥15° is more than 80%. In the manufacturing method, a cold-rolling is performed under rolling reduction ratio of ≥70% and rolling temperature of ≤50°C; a last annealing is performed at 700-900°C; and holding time is 4-24 hr.;COPYRIGHT: (C)2011,JPO&INPIT