Investigation of quasi-cleavage in a hydrogen charged maraging stainless steel

Slow strain rate tests on hydrogen-containing specimens of PH13–8Mo maraging stainless steel showed H-assisted subcritical quasi-cleavage cracking, accelerating material failure. Fractographic analysis revealed that is composed flat brittle areas and rougher areas. Electron backscatter diffraction (EBSD) was performed a secondary subcritically grown crack. High resolution EBSD significant crystal lattice rotation, hence consequential plastic deformation, concentrated between the main crack tip cracks located ahead it. Quasi-cleavage consisted {100} cleavage connected by ductile ridges, suggesting discontinuous mechanism, involving re-initiation new tip.