After 0.5 - 1.5 mass , Cr 10.0 - 30.0 mass heating the high

摘要

PROBLEM TO BE SOLVED: To provide a heat treatment method for making fine of crystal grains in a high nitrogen stainless steel with which the crystal grains can be made to fine only with the heat treatment without applying any processing, and the high nitrogen stainless steel.;SOLUTION: The heat treatment method for making fine of the crystal grains in the high nitrogen stainless steel, is performed as the followings, with which after austenizing the high nitrogen stainless steel by heating, an isothermal transformation treatment from the austenite structure into a mixed structure composed of ferrite and nitride and thereafter, reheating and reversed transformation treatment from the above mixed structure into the austenite are applied to make fine of the crystal grains. Furthermore, the isothermal transformation treatment and the reversed transformation treatment are repeated, and the crystal grains can be made to fine.;COPYRIGHT: (C)2007,JPO&INPIT