Nitretação a plasma de aço inoxidável austenítico sinterizado AISI 316L com adição de ítria

Abstract

In this work, plasma nitriding of sintered 316L austenitic stainless steel was performed, with and without addition of yttria. The hollow cathode type configuration was used in the nitriding reactor. Initially varying the position of the samples in the chamber, the time, the temperature and the working pressure of the gases. The adequate nitriding condition was reached, that is, the one that avoided the formation of nitrides, provided the formation of expanded austenite and thicker nitrided layer. This condition occurred in a treatment carried out at 400 °C, for 4 h, under a working pressure of 25 Pa, with a mixture of gases in the proportion 3N2:1H2. The thicker nitrided layer also contributed to finest performance of 316L stainless steel in the scratch tests, which exhibit lower friction force, minor width and depth of scratches, and lower wear volume in the ideal nitriding condition. [resumo fornecido pelo autor]