抄録
The susceptibility to hydrogen embrittlement of two types of high strength austenitic stainless steels were investigated by conducting a series of slow strain rate tests (SSRT) in hydrogen gas with a pressure of around 100 MPa. The JIS-SUS304 and JIS-SUS316L austenitic stainless steels were also tested for a comparative purpose. In JIS-SUS304, the tensile strength and reduction of area in hydrogen gas were much lower than those in air. In contrast, in JIS-SUS316L, the degradation of those tensile properties in hydrogen gas was not so significant. The high strength austenitic stainless steels also exhibited an excellent resistance both in tensile strength and ductility in hydrogen gas. It was presumed that, in those high strength austenitic stainless steels, a small amount of added elements, N and Nb, increased the strength level as well as the stability of austenitic phase, which thereby led to the excellent resistance against hydrogen embrittlement.
