The effects of hydrogen on the deformation mechanism of <001>-oriented single crystals of Hadfield steel were studied under tension at temperatures of 77 and 300K. An increase in intensity of twinning was observed for samples charged with hydrogen, and it was assumed that this was the reason for the increase in elongation to fracture. Despite the high elongation to failure, the fracture surfaces displayed a brittle component.

Hydrogen-Induced Twinning in <001> Hadfield Steel Single Crystals. E.G.Astafurova, G.G.Zakharova, H.J.Maier: Scripta Materialia, 2010, 63[12], 1189-92