Hydrogen environment embrittlement of austenitic stainless steels at low temperatures - Study on low temperature materials used in WE-NET 13

Hydrogen environment embrittlement (HEE) of the austenitic stainless steels (SSs) of type 304, 3041, 316, 316L and 3161.N with solution-annealed and sensitized heat-treatments were investigated in high-pressure of 1. 1 MPa hydrogen and helium in the temperature range from 300 K to 80 K with the strain rates from 4.2x10(-5) to 4.2x10(-2) s(-1). Hydrogen showed marked effect on the tensile properties, especially reduction of area, of type 304, 304L and 316 SSs. Hydrogen also showed a little effect on the tensile properties of type 316L SS, and no effect on the tensile properties of type 316LN SS. HEE of the materials increased with decreasing strain rate. HEE of the solution-annealed materials increased with decreasing temperature, reached a maximum at around 220 K and decreased abruptly with decreasing temperature down to 80 K. HEE of the sensitized materials was severer than that of the solution-treated ones. It is discussed that HEE of the austenitic SSs is controlled by the hydrogen diffusion with the dislocation movement during plastic transformation.