This article presents shot-peening effect on the structure, microhardness, and compressive stresses of the austenitic steel 1.4539. The research shows strengthening of the top layer and the formation of compressive stresses in the subsurface layers of the shot-peening elements.[b]Keyword[/b]: austenitic steel 1.4539, residual stresses, Waisman-Phillips’a metho

The stress distribution function in the surface layer is created as a result of using stress measurements on the surfaces of C45 steel samples after shot peening. Stresses were measured by X-ray diffraction with the use of the PSF-3M device from the Rigaku Company. For measuring residual stresses, subsequent layers of the top surface of the material were used as a basis, and these were obtained through electrochemical etching. The test results i.e. distance into the material, sample hardness, shot type, stress) were entered into the stepwise multiple regression program. A record of residual stresses was obtained in the form of the second-degree regression function of three independent variables with interactions. The obtained analytical form of the residual stress function was used in the FUNVAL3.EXE program to calculate the tabular values of stresses permeating into the material. For the analytical description of the stress distribution, the REGPOLY.EXE regression program was used, which creates a polynomial functional form of the residual stress distribution. The plot form of the residual stress distribution was obtained using the EXCEL Microsoft Office 2000 program.

This publication presents the performance properties of 30HGSA steel after various surface treatments involving hybrid graphene coating, shot peening, and graphene oxide coating, and of the material in its delivery state used in aerospace structures. Performance tests were carried out on the structure, measuring surface roughness, microhardness, corrosion, residual stresses and bending strength for all surface treatments. It has been demonstrated that hybrid graphitization results in increased surface roughness, increased compressive stress and a beneficial increase in the bending strength of the sample compared to other research groups. A new method of strengthening steel surfaces by hybrid graphitization, consisting of coating the steel surface with graphene oxide and shot peening, has been described. The mechanism of hybrid graphitization affecting the increase in the performance properties of 30HGSA steel, including a 43% increase in maximum bending strength compared to BM, has been presented.

This publication presents the structure and mechanical properties of an aluminum oxide-based ceramic material. The ceramic material was strengthened by shot peening at the PEEN-IMP facility (patent PL 294718) using tungsten carbide balls. The value of the critical stress intensity factor was determined on the basis of Vickers hardness measurements of the shot-peened ceramic tiles at various time intervals. The Anstis and Niihara formulas were used to determine this value. The shot peening time T [min] of the samples was set to 40, 60, and 120 min, respectively. Based on the test results, a polynomial regression program was used to determine the functionof the degree of change in the strength of alumina ceramics in relation to the shot peening time. The optimal shot peening time was determined based on a graph and analytically.