Bernatskyy A. Improving the physical-mechanical properties of the surface layers of steel products by laser and laser-microplasma alloying

In the thesis on the basis of metal-physical governance theories of structure formation, set the impact of variation mode process of laser and combined laser-microplasma alloying to change the physical-mechanical properties of the doped layers of steel products, depending on the parameters of the structures that are formed in these layers. This makes it possible to predict and improve the physical-mechanical properties of the doped layers of steel products. Recommendations for the management of structure formation in laser and combined laser- microplasma alloying have been given. For the formation of structures that provide a high level of physical- mechanical properties of structural strength, it is recommended to carry out the alloying, at a value of linear energy per unit length 300...450 J/mm. It is found that the combined laser and laser-microplasma alloying, susceptibility to cracking due, concentration and structural changes that result in a sudden grainboundary concentration gradient that promotes the formation of near-boundary zones of carbide phases, their clusters and cause the formation of dense dislocation clusters aimed - local internal stress concentrators, and hence cell origin and propagation of cracks.