Effect of laser shock peening on tensile properties and microstructure of selective laser melted 316L stainless steel with different build directions

Abstract

316L stainless steel tensile samples were fabricated via selective laser melting (SLM), wherein the build directions (BD) deviated from the tensile directions by 0°, 45°, and 90°. The effects of BD and laser shock peening (LSP) on compressive residual stress distribution, microstructure, texture, and tensile properties were investigated. The intensity and volume fraction of strong <110> fibre texture decreased after LSP, and the sample with a build angle of 90° had the weakest intensity and the least volume fraction. A tensile test was conducted at 25 °C temperature to investigate the effects of the BD and LSP on strength and ductility. LSP resulted in a noticeable improvement in the strength of all the samples, but the ductility of the samples with 0° and 45° build angles declined. Additionally, it was found that 316L fabricated via SLM with a build angle of 90° and subjected to LSP had the optimal combination of strength and ductility.