Hadfield steel work hardening

A mechanical surface effect in austenitic manganese steels where impact and compressive loads lead to an extreme local increase in hardness via dislocation pile-ups.

Manganese hard steel hardens on the surface when it is strongly beaten or pressed. That happens because dislocations pile up in the structure – the material becomes hard and tough there. When welding, this is a problem: The heat can soften this hardened zone again, or hard, brittle spots can form that may crack. When welding such steel, you must keep the heat low and cool the weld well. After welding, you must not rework or grind the hardened zone, otherwise you lose exactly the hardness that the steel got through cold working.

MetallurgieSchweißtechnik