Inhomogeneity of deformation of surfaced stainless steel

The work is devoted to the study of the inhomogeneity of deformation of steel samples with laser surfacing. Highly nitrogenous austenitic stainless steel of the 08Kh18N6AG10S grade was selected as the substrate material in the state as received. To improve the mechanical properties of structural elements that operate under conditions of impact and abrasive wear, a surfacing of Ni–7Cr–6Fe + 60 % WC composite powder was applied to the steel. The surfacing was carried out with a change in the power of laser radiation from 1 to 3 kW and a change in the scanning speed from 0.005 to 0.040 m/s. The penetration depth of a single roller decreases with increasing scanning speed. The microhardness varies widely in the surfacing thickness (from 7,000 ± 80 to 13,500 ± 70 MPa) and decreases with increasing the scanning speed. Using the speckle photography method in the process of uniaxial extension of flat samples, it was found that the modes of laser surfacing also affect the level of inhomogeneity of deformation of micro-volumes of the deposited layer and the substrate. At the elastoplastic transition, the coefficient of variation of local deformations in the sample increases with an increase in the specific energy of laser surfacing. Coatings made of Ni – Cr – Fe + WC composite powder, obtained by laser surfacing under specified conditions, make it possible to increase the hardness and service life of structural elements of rotary controlled systems made of 08Kh18N6AG10S steel.