Modeling of the chemical composition of the layer fused with a powder electrode

Abstract

Problem. The work is devoted to the problem of the formation of high-quality deposited metal during the restoration of parts of small diameters with insignificant dimensions of wear. Goal. The purpose of the work is the development of a mathematical model for calculating the composition of metal deposited by flux-cored wire with forced transfer of the electrode metal. Methodology. The composition of the core of the powder electrode should ensure protection of the deposited metal from the action of air, ensure alloying of the metal, its deoxidation, high-quality formation of the bead, easy separation of the slag crust, minimal splashing of the molten metal, the absence of pores, cracks, and slag inclusions in the deposited layer. However, a number of surfacing self-protecting powder electrodes contain a significant amount of gas-slag-forming components in the charge. The result can be: failure of the rollers to fuse with each other and with the base metal, loss of alloying elements due to oxidation, slagging of the rollers, and slag runoff. In order to ensure the specified chemical composition of the deposited metal, a mathematical model for calculating the composition of a layer deposited by a powder electrode with forced metal transfer has been developed, which id correctly taken into account during the configuration of the rollers relative to each other and relative to the base metal. Results. The influence of the deposition step and the coefficient of reinforcement of the deposited roll on the value of the share of the metal of the previous roll of the deposited layer in the next roll was determined. The influence of the surfacing step on the quality of the formation of the surfacing layer was determined experimentally. Practical value. Technological recommendations have been developed and proposed for applying a layer with powder electrodes with forced metal transfer, which ensure high quality of the deposited metal with the formation of a layer of the required chemical composition. It was established that if the recommendations regarding the technological parameters of the process are followed, the necessary chemical composition of the deposited metal is achieved already in the second layer.