Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (51권3호 172-178)

Study on the Effects of Oxidant on Chemical Passivation Treatment of Low Nickel Stainless Steel

저니켈 스테인리스강의 화학적 부동태막 형성에 산화제가 미치는 영향

최종범;이경황;윤용섭;
Choi, Jong-Beom;Lee, Kyung-Hwang;Yun, Yong-Sup;

한국해양대학교 기관시스템공학과;포항산업과학연구원 소재이용연구그룹;
Department of Marine Engineering, Korea Maritime and Ocean University;Research Institute of Industrial Science & Technology;

DOI : 10.5695/JKISE.2018.51.3.172

Abstract

In this paper, effects of potassium permanganate, pottasium dichromate, sodium molybdate on lean duplex stainless steel were studied by GDOES, OCP, potentiodynamic curves. The stainless steels were chemically passivated in each nitric acid solutions containing 4wt.% oxidants for 1 hour. As a result, when potassium dichromate or sodium molybdate was added, content of Fe was decreased and content of Cr was increased. Consequently, corrosion resistance of passive film was increased. But in case of potassium permanganate was added, contrastively, content of Fe was increased and content of Cr was decreased. So corrosion resistance was decreased. Adding sodium molybdate in nitric acid for chemical surface treatment process was the most effective among oxidants and also it showed the most stable anti-corrosion in SST.

Keywords

GDOES(Glow Discharge Optical Emission Spectroscopy);OCP(Open Circuit Potential);Potentiodynamic curves;Chemical surface treatment process;Oxidant;Salt Spray Test;