Effects of Nitrogen and Tensile Direction on Stress Corrosion Cracking Susceptibility of Ni-Free FeCrMnC-Based Duplex Stainless Steels

Heon-Young Ha; Chang-Hoon Lee; Tae-Ho Lee; Sangshik Kim

doi:10.3390/ma10030294

Effects of Nitrogen and Tensile Direction on Stress Corrosion Cracking Susceptibility of Ni-Free FeCrMnC-Based Duplex Stainless Steels

Materials (Basel). 2017 Mar 15;10(3):294. doi: 10.3390/ma10030294.

Authors

Heon-Young Ha¹, Chang-Hoon Lee², Tae-Ho Lee³, Sangshik Kim⁴

Affiliations

¹ Ferrous Alloy Department, Korea Institute of Materials Science, Changwon 51508, Gyeongnam, Korea. hyha2007@kims.re.kr.
² Ferrous Alloy Department, Korea Institute of Materials Science, Changwon 51508, Gyeongnam, Korea. lee1626@kims.re.kr.
³ Ferrous Alloy Department, Korea Institute of Materials Science, Changwon 51508, Gyeongnam, Korea. lth@kims.re.kr.
⁴ Department of Materials Engineering and Convergence Technology, Research Center for Aircraft Part Technology, Gyeongsang National University, Chinju 52828, Gyeongnam, Korea. sang@gnu.ac.kr.

Abstract

Stress corrosion cracking (SCC) behavior of Ni-free duplex stainless steels containing N and C (Fe_balance-19Cr-8Mn-0.25C-(0.03, 0.21)N, in wt %) was investigated by using a slow strain rate test (SSRT) in air and aqueous NaCl solution with different tensile directions, including parallel (longitudinal) and perpendicular (transverse) to the rolling direction. It was found that alloying N was effective in increasing the resistance to SCC, while it was higher along the longitudinal direction than the transverse direction. The SCC susceptibility of the two alloys was assessed based on the electrochemical resistance to pitting corrosion, the corrosion morphology, and the fractographic analysis.

Keywords: duplex stainless steel; nitrogen; pitting corrosion; stress corrosion cracking.