The paper considers a method for eliminating residual gas inclusions after the induction surfacing of reinforcing rings on internal combustion engine valves made of heat-resistant chromium-nickel alloy EP-616A. Residual gas inclusions negatively affect the engine operation, impairing the tightness and efficiency of the valves. Elimination of defects will restore the efficiency and productivity of the engine in which the valves are located, prevent back impacts and damage resulting from leaky valve closure, extend service life and reduce repair and replacement costs due to the absence of wear and damage to such parts as seats and bushings, and will also lead to fuel savings, since defective valves can lead to improper operation of the engine, which will increase its fuel consumption. Laser remelting is investigated as a method of minimizing residual gas inclusions and additional hardening of surfacing rings. Technological modes of remelting have been experimentally selected. Visual and capillary control methods, as well as metallographic studies were carried out. According to the results of the capillary control method, a significant percentage of defects in the basic technology was revealed. The microstructure study showed the absence of gas inclusions after remelting, as well as a satisfactory structure of the remelted layer with the formation of a directed dendritic structure. Laser remelting does not require additional operations, such as drilling, milling, grinding, which saves time and resources. The optimal range of linear energies of 550‒590 J/cm has been established according to the criterion of penetration depth and shape of the melted ring. Remelting in an optimal range of linear energies also avoids hot cracks and pores. The metal structure of the reinforcing ring after remelting corresponds to the initial structure of the ring obtained by the basic induction surfacing technology. Thus, visual-measuring and luminescent control, as well as the study of the microstructure, showed the possibility of using laser remelting to eliminate surfacing defects.
