METHOD OF HEAT TREATMENT FOR FORMATION OF HIGH-STRENGTH AUSTENITIC SURFACE LAYER IN STAINLESS STEEL Russian patent published in 1999 - IPC

FIELD: heat treatment of stainless steels for formation of high-strength austenitic surface layer. SUBSTANCE: method for heat treatment for formation of austenitic surface layer with 0.3 wt.% or more of dissolved nitrogen in finally molded parts from stainless steel provides for steel nitriding in gas atmosphere containing nitrogen at temperature from 1000 to 1200 C and subsequent cooling with the rate to avoid separation of nitride. Stainless steel is used in the form of stainless austenitic, martensitic, ferritic, ferritic-austenitic and ferritic-martensitic steels. The method is realized at pressure in gas atmosphere during nitriding differing from normal pressure. Surface layer may be subjected to diffusion hardening by subsequent repeated heating to temperature equal to or below 650 C. EFFECT: improved wear resistance at load in the form of shocks, jerks, cavitation and drop impacts. 9 cl, 5 dwg