Differentiated treatment to obtain naturally reinforced surface layers on manganese steels

Conclusions

• 1. Laser hardening using the method selected reduces the microhardness of steels with a primarily α-martensitic structure but increases it in steels with a structure of metastable austenite. The maximum microhardness is obtained after laser treatment of previously hardened G14 steel, in which austenite is least stable in loading.

• 2. Preliminary plastic deformation has a dissimilar influence on the microhardness of laser treated manganese steels. If preliminary deformation reduces the stability of austenite toward the γ-α′-transformation in loading an increase in microhardness is observed after laser treatment while if as the result of preliminary deformation a primarily martensitic structure is formed or there is a significant increase in the stability of austenite toward the γ-α′-transformation in loading the microhardness drops after laser treatment.

• 3. By a combination of through hardening, preliminary deformation, and laser treatment it is possible to regulate the stability of the austenite and the level of microhardness and also to obtain a naturally reinforced layer with high hardness, strength, and plasticity.