Processing Parameters Impact on Microstructure and Mechanical Properties of ASTM A36 Steel Laser Welding

Abstract

Abstract In recent years there have been advances in the development of processes for obtaining and building steel and metal alloys. These developments require an increasingly deeper and more detailed understanding of the phenomena that involve phase transformations, arising from the processing of obtaining, forming, welding and application of these materials. At the same time, the evolution of laser welding technologies is making these processes increasingly attractive for industrial applications. In this context, this work proposes to study the effect of different combinations of parameters on the visual, mechanical and microstructural characteristics of the laser welding beads. To evaluate the influence of process parameters, 8 combinations of speed and power were used, keeping the heat input constant, in the welding of ASTM A36 steel. The study aims to compare the influence of the variation of these parameters in the weld region and its relationship with the mechanical properties, considering that, despite the constant heat input, there is still a variation in the power density and the interaction time. The results indicate that the material used has a wide processing window, since the tensile tests, microhardness and metallographic analyzes showed similar results in the range of evaluated parameters. Samples welded with powers between 2 kW and 8 kW showed good mechanical performance, but an increase in process instability was observed, with an increase in power density and a reduction in the interaction time.