Hydrogen diffusivity, uptake and embrittlement of solution annealed and cold deformed austenitic stainless steel 1.4435 at hydrogen pressures up to 1000 bar and 200 °C

Austenitic stainless steel 1.4435, a candidate material for high-pressure tubing for hydrogen applications, was investigated in two different stages of cold deformation (0 and 27%) regarding its hydrogen embrittlement tendency. The determination of effective diffusion coefficients revealed slightly increased diffusion kinetics at 60°C for the cold-reduced material (8.0 · 10-15 m²/s) compared to the solution annealed one (5.0 · 10-15 m²/s). High-pressure gaseous hydrogen charging shows no differences regarding the degree of cold deformation with a maximum hydrogen concentration of 112 wt.-ppm. Furthermore, a significant ductility loss expressed by the ratio of the reduction of area was observed.