STAINLESS STEEL HAVING EXCELLENT CORROSION FATIGUE RESISTANCE AND SEAWATER CORROSION RESISTANCE AND ITS PRODUCTION

摘要

PURPOSE:To produce a stainless steel having excellent corrosion fatigue resistance and seawater corrosion resistance by specifying the structure of a steel contg. specific ratios of C, Si, Mn, Ni, Cr, N and Nb to the recrystalizing double constitutional structure. CONSTITUTION:The steel contg., by weight, =0.03% C, =2.0% Si, =5.0% Mn, 6-13% Ni, 16-21% Cr, 0.10-0.30% N, 0.02-0.25% Nb and the balance consisting of Fe with impure elements is prepared. Said steel is heated to 1,100-1,300 deg.C, is subjected to rolling at =50% working rate at the coarse rolling temp. of 1,000-1,200 deg.C and thereafter is cooled at the cooling rate of =4 deg.C/min. The steel is then worked at =20% working ratio at the finish rolling temp. of 800-1,000 deg.C and is cooled at the cooling rate of =4 deg.C/min to make the structure to the recrystalizing double constitutional structure. The austenite stainless steel having the excellent corrosion fatigue resisting strength, yield strength, seawater corrosion resistance and ductility is thereby obtd.