Influence of Metallurgical Factors on Hydrogen Damage of Austenitic Stainless Steels
1978 Volume 64 Issue 2 Pages 288-296
Details
1978 Volume 64 Issue 2 Pages 288-296
The damage of austenitic stainless steels heated at high temperature and high pressures of hydrogen was investigated with reference to the metallurgical factors. Main results obtained are as follows:
1) The solubility of hydrogen (wtppm) in 304 steel hydrogenated at T: 473-723 (K) under P: 10-300 (atm) is given by the following Sieverts' equation,
[H] =9.261/√P exp (-1470/RT)
where, R is the gas constant (cal/mol).
2) The embrittlement of 304 steel increased rapidly with increasing hydrogen content until about 30 wtppm above which the influence of hydrogen content weakens.
3) The sensitivity to hydrogen embrittlement (HE) of austenitic stainless steels increased largely with decreasing Ni equivalent less than about 25% and the better correlation between the sensitivity to HE and the volume of stress-induced martensite produced under tensile testing can be obtained.
4) The sensitivity to HE of austenitic stainless steels increased remarkably with increasing the grain size and the volume of carbide precipitated at grain boundary or ferrite phases precipitated in austenitic matrix. The existence of notch in the tensile specimen can also increase it.
