Heat Treatment Effect on Pitting Corrosion of Super Duplex Stainless Steel UNS S32750 GTA Welds

Abstract:

The purpose of this study was to investigate the effect of heat treatment (930°C, 1080°C, 1230°C) followed by quenching on the pitting corrosion resistance, sigma phase precipitation, and microstructural change of a super duplex stainless steel (UNS S32750) welds made by gas tungsten arc (GTA). Based on the microstructural examination, the σ phase was formed in welds heat treated at 930°C while there were little σ phases formed in welds experienced the relatively fast cooling from 1080°C and 1230°C. Accordingly, the most weight loss due to pitting corrosion occurred in the as received base and weld metals heat treated at 930°C. It was confirmed that the pitting corrosion occurred in the phase boundaries of ferrite/sigma and austenite/sigma.

• Periodical: Advanced Materials Research (Volume 746)
• Pages: 467-472
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.746.467
• Online since: August 2013
• Authors: In June Moon, Bok Su Jang, Jin Hyun Koh
• Keywords: Gas Tungsten Arc Welding, Heat Treatment, Pitting, Super Duplex Stainless Steel, σ-Phase

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