Hadfield Steel Deformation Twinning
A plastic deformation mechanism within the austenitic microstructure where crystallographic planes are mirrored via mechanical loading. This contributes significantly to the high work-hardening rate.
Manganese hard steel becomes hard through cold working – under heavy mechanical load, twin boundaries form in the structure, making the material extremely wear-resistant. When welding, you have to be careful not to ruin this property. The heat input must not be too high, otherwise the grain grows and the steel loses its toughness. Also, the material tends to crack if you put in too much heat or cool the weld too fast. Keep the interpass temperature low and weld preferably with an austenitic filler metal, then the weld stays tough and crack-free.