Characteristic Evaluation according to Heat Treatment Conditions of Super Duplex Stainless Steel with Additive 0.2% N - Part 3: Corrosion Characteristic

J. Ocean Eng. Technol. 2009;23(5):85-91.

Ahn Seok-Hwan,Kang Heung-Joo,Seo Hyun-Soo,Nam Ki-Woo,Lee Kun-Chan

School of Mechanical Engineering Pukyong National University,Busan Maritime High School,Defence Agency for Technology and Quality,Division of Materials Science and Engineering Pukyong National University,Showa Denko K.K.

0.2% N을 첨가한 수퍼 2상 스테인리스강의 열처리 조건에 따른 특성 평가 - 제3보: 부식특성

안석환,강흥주,서현수,남기우,이건찬

부경대학교 기계공학부,부산해사고등학교,국방기술품질원,부경대학교 신소재공학부,쇼와전공(주)

Keywords: Super duplex stainless steel, Corrosion, Heat treatment condition, Sol-gel method, $SiO_2$ colloidal-coating $SiO_2$

핵심용어: 수퍼 2상 스테인리스강, 부식, 열처리조건, 졸-겔법, 콜로이달 코팅

Abstract

A stainless steel that contains aggressive negative ion was known to decrease the corrosion resistance. Stainless steel with super corrosion resistance was developed for improvement of corrosion resistance. Super duplex stainless steel is widely used under sever environment because of good mechanical properties and corrosion resistance. Also, Super duplex stainless steel has long life in severe environments by showing the enough strength and corrosion resistance. But duplex stainless steel is not stabilized compared to austenite stainless steel in corrosion resistance. In this study, corrosion characteristic were investigated to super duplex stainless steel with additive 0.2% nitrogen with $SiO_2$ thin films coated or no coated by sol-gel method in 3.5% NaCl. From test results, corrosion current density in the heat-treated specimen for ${sigma}$ phase precipitation was higher than that of different heat-treated specimen. Also, $SiO_2$ colloidal-coated specimen had not occurred almost corrosion.