Research on Fatigue of Cr-Mo Steel for Hydrogen Storage Vessels

A pre-normative project, “Material testing and recommendations for hydrogen components under fatigue, MATHRYCE” under the EU joint research program dealt with hydrogen enhanced fatigue in Q&T (YS=600MPa) low alloy Cr-Mo steel and pressure vessel design. The project was concluded by cyclic testing of pre-notched vessels by hydraulic and hydrogen pressure loading. This paper display part of the fatigue tests performed under hydrogen pressure, including fatigue crack initiation analysis from 0.5MPa H₂ to 103MPa H₂. Notable differences, but explainable correlations between results of various test types were found. Some implications to possible improvements of hydrogen pressure vessels design standards are also presented.