Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (37권1호 53-57)

RF Plasma Nitriding of AISI 304 Stainless Steel


Kim, Sun-Kyu;Yoo, Jung-Sik;Matthew P. Fewell;


Traditional Technology Innovation Research Laboratory School of Materials Science and Engineering, University of Ulsan;LG CNS;Physics and Electronic Engineering, University of New England;

Abstract

Austenitic stainless steel AISI 304 was nitrided in a low-pressure RF plasma using pure nitrogen. With a treatment of time of 4.0h at $400^{circ}C$, the nitrogen-rich layer on the sample was $3mu extrm{m}$thick and had a hardness of approximately 4.4 times higher than that of untreated material. XRD data showed that as the process temperature rose from 350∼$450^{circ}C$, the expanded austenite peaks became more prominent while the austenite peaks became weaker. Expanded austenite was transformed to ferrite and CrN at the treatment of$ 500^{circ}C$. Langmuir probe measurements showed that electron density decreased above $450^{circ}C$.

Keywords

RF plasma nitriding;Austenitic stainless steel;AISI 304;Expanded austenite;