2 Heat treatment method of high nitrogen duplex stainless steels

摘要

PURPOSE: A method for heat treating high nitrogen dual phase stainless steel is provided to give optimum heat treatment conditions capable of minimizing nitrogen concentration change of stainless steel in heat treating dual phase stainless steel containing nitrogen with temperature, atmosphere and time of heat treatment changed. CONSTITUTION: The method for heat treating high nitrogen dual phase stainless steel comprises the process of performing heat treatment by mixing nitrogen with argon gas in a volume ratio of 50:50 to minimize solubility change of nitrogen in carrying out heat treatment of annealing and solid treatment of dual phase stainless steel comprising 0.03 wt.% or less of C, 0.5 wt.% or less of Si, 1.0 wt.% or less of Mn, 20 to 25 wt.% of Cr, 5 to 7 wt.% of Ni, 5 wt.% or less of Mo, 1 wt.% or less of Cu, 1 wt.% or less of W, 0.2 to 0.3 wt.% of N and a balance of Fe and other inevitable impurities in the temperature range of 1050 to 1350 deg.C.