Kinetics and Mechanism of Liquid-Phase Interaction of Carbide Steels with a Steel Base

Abstract

Resume. To develop a mathematical model of the interaction of a carbide steel coating with a steel base under conditions of the formation of a liquid phase.Methods. The average value of the transition zone was experimentally determined using a PMT-3 device. The size of the transition zone in the carbide steel layer was determined using a MAR-2 X-ray microanalyzer.Results. A mathematical model of the interaction of a carbide steel coating with a steel base under conditions of liquid phase formation has been developed. It is established that the distribution of carbon in the transition zone of the carbide steel layer (δL) and the steel base (δS) is described by an exponential dependence, and the above technique allows to predict the size of the transition zone with high accuracy, which confirms the corollary of the theory that when applying a layer on a base with a lower carbon content, the width of the transition zone will be greater, and the speed of the melting of the base is less. properties of coatings made of carbide steels of various compositions. High adhesion strength of coatings to the substrate after vacuum sintering has been established (for carbide steel of 10% TiC, steel Cr6V3Mo 116 MPa; for carbide steel of 40% TiC, steel Cr6V3Mo 131 MPa; for carbide steel of 40% TiC, steel Cr12Mo 220 MPa), which in combination with their high physical-mechanical properties allow us to recommend the method of plasma spraying of coatings made of carbide steels for the restoration of worn surfaces of parts and tools for various purposes.Conclusion. The developed mathematical model makes it possible to calculate the size of the intermediate layer, as well as the diffusion coefficients of carbon in the liquid phase and in the steel base.