Laser Refining of a Surface Layer with Silicon Carbide

Abstract

The article discusses the effect of adding silicon carbide by laser remelting of low-carbon steel. Tests in laser remelting were carried out with energy inputs ranging between 10 and 80 J/mm 2 with the most favorable degree, i.e., 30%, of overlapping of individual trace. Sufficient energy input was necessary to dissolve silicon-carbide with iron. A microchemical analysis of the remelted layer confirmed the dissolution of silicon carbide and formation of a smaller portion of martensite (10–20%) and of suesite Fe3Si (65–80%). It was found that the test-specimen deformation was smallest with the laser-beam in the zig-zag motion. The surface was also assessed visually. The choice of adequate remelting conditions reduced, i.e., prevented, the occurrence of cracks and other defects. The influence of energy input and the mode of laser-beam travel on the efficiency of remelting, i.e., refining, was described by a ratio of the width of the remelted surface layer to its depth, which should amount to around 5:1.