DUPLEX STAINLESS STEEL, AND PROCESS FOR PRODUCTION THEREOF.

摘要

Provided is a duplex stainless steel having high strength and high toughness. This stainless steel has a chemical composition containing, in mass%, 0.030% or less of C, 0.20-1.00% of Si, 8.00% or less of Mn, 0.040% or less of P, 0.0100% or less of S, more than 2.00% and 4.00% or less of Cu, 4.00-8.00% of Ni, 20.0-30.0% of Cr, 0.50% or more and less than 2.00% of Mo, 0.100-0.350% of N and 0.040% or less of sol.Al, with the remainder being made up by Fe and impurities, and has a structure containing a ferrite at a content of 30-70% wherein the ferrite has a hardness of 300 Hv10gf or more.