Effect of nickel equivalent on hydrogen gas embrittlement of austenitic stainless steels based on type 316 at low temperatures

✍ Scribed by Lin Zhang; Mao Wen; Masaaki Imade; Seiji Fukuyama; Kiyoshi Yokogawa

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 738 KB
• Volume: 56
• Category: Article
• ISSN: 1359-6454
• DOI: 10.1016/j.actamat.2008.03.022

✦ Synopsis

The effect of nickel equivalent on hydrogen gas embrittlement (HGE) of austenitic stainless steels of Fe-(10-20)Ni-17Cr-2Mo alloys vacuum-melted in a laboratory, based on type 316 stainless steel, was investigated. Tensile tests were conducted in hydrogen and helium at 1 MPa in the temperature range from 80 to 300 K. It was found that HGE of the alloys below a nickel equivalent of 27% increased with decreasing temperature, reached a maximum at 200 K, and then decreased with further decreasing temperature, whereas no HGE occurred above the nickel equivalent of 27%. It was observed that the content of strain-induced a 0 martensite increased with decreasing temperature and nickel equivalent, and hydrogen-induced fracture occurred mainly along a 0 martensite structure. Thus, the susceptibility to HGE depended on nickel equivalent. It was discussed that HGE was controlled by strain-induced a 0 martensite above 200 K, whereas it was controlled by hydrogen transport below 200 K.