Determining the Residual Stresses in High-Chromium Cast Iron Plasma Coatings

Abstract

The paper presents the results of studies of the plasma spraying modes effect on the level of residual stresses in coatings. The analysis of experimental data has shown that the sign of residual stresses is not changed in the spraying process. The magnitude of the tensile stresses mainly depends on the temperature of samples heating, the biggest influence being that of plasma torch current arc. An increase in the current leads to an increase in the substrate temperature, which is explained by the increase in the thermal power of the plasma jet. An increase in the flow rate of the plasma-forming gas leads to a decrease in the temperature of the samples, since the heat content of the plasma decreases. An increase in the spraying distance has a similar effect, and its increase leads to a decrease in the substrate temperature. We obtained the functional dependence of the residual stress level on the plasma spraying modes.