Effect of Mo, Ti, Nb on the hot salt corrosion behavior of ferritic stainless steels for automotive exhaust system

J. Ocean Eng. Technol. 1997;11(3):48-55.

자동차배기관용 페라이트계 스테인레스강의 고온염부식에 미치는 Mo, Ti, Nb 원소의 영향

김수정,안용식

부산대학교 대학원 금속공학과,부경대학교 재료공학과

Keywords: Ferritic stainless steel, High temperature NaCl, Corrosion rate, Alloying element

핵심용어: 페라이트계 스테인레스강, 고온염, 부식속도, 합금원소

Abstract

The steel for automotive exhaust system needs a good corrosion resistance at the atmosphere of high temperature NaCl. Effect of the alloying elements Me, Ti, Nb on the NaCl induced hot corrosion behavior was investigated at the temperatures between 55$0^{circ}C$ and 75$0^{circ}C$ for 18Cr ferritic stainless steels. The weight loss by corrosion has increased linearly with corrosion cycle time, and the corrosion rate has accelerated at higher temperature. The alloying of Mo significantly improved corrosion resistance of the steel and the effect was more pronounced at higher temperature. The addition of alloying elements Ti, Nb have also shown improved corrosion resistance by formation of Ti(C,N) or Nb(C, N) precipitates.