The Influence of Treatment Condition During Low Temperature Plasma Carburizing of AISI304L Stainless Steel

doi:2011.25.1.56

J. Ocean Eng. Technol. > Volume 25(1); 2011 > Article

J. Ocean Eng. Technol. 2011;25(1):56-60.
DOI: https://doi.org/10.5574/KSOE.2011.25.1.056

Lee In-Sup

Department of Advanced Materials Engineering Dongeui University

AISI304L 강에 저온 플라즈마침탄 처리 시 처리조건에 따른 표면특성평가

이인섭

동의대학교 신소재공학과

Keywords: Austenitic stainless steel, Low temperature plasma carburizing, Expanded austenite, Corrosion resistance

핵심용어: 오스테나이트계 스테인레스강, 저온 플라즈마침탄, 확장된 오스테나이트, 내식성

Abstract

A low temperature plasma carburizing process was performed to AISI 304L austenitic stainless steel to achieve the enhancement of surface hardness without a compromise in their corrosion resistance. Attempts were made to investigate the influence of the processing temperatures on the surface-hardened layer during low temperature plasma carburizng in order to obtain the optimum processing conditions. The expanded austenite (${gamma}C$) was formed on all the treated surfaces. Precipitates of chromium carbides were detected in the hardened layer (C-enriched layer) only for the specimen treated at $500^{circ}C$. The hardened layer thickness of ${gamma}C$ increased up to about $35;{mu}m$, with increasing treatment temperature. The surface hardness reached about 1000 $HK_{0.05}$, which is about 4 times higher than that of the untreated sample (250 $HK_{0.05}$). Minor loss in corrosion resistance was observed for the specimens treated at temperatures of $310^{circ}C-450^{circ}C$ compared with untreated austenitic stainless steel. Particularly, the precipitation of chromium carbides at $500^{circ}C$ led to a significant decrease in the corrosion resistance.