A thermo-mechanical finite element method simulation of 304L stainless steel during laser solid forming with pre-deformation substrate

A 3D parametric model was developed to perform the transient thermo-mechanical finite element method (FEM) simulation on the transient stress field as well as the residual stress field and the final shape of substrate for the laser solid forming (LSF) of 304L stainless steel with the pre-deformation substrate. The results showed that the pre-deformation of the substrate can effectively alleviate the warping of substrate during LSF, and improve the roughness of the substrate after LSF, which will be in favor of avoiding the decrease of the forming precision and even the processing failure which caused by the distortion of the substrate during LSF. For multi-pass single-layer laser deposition, it is found that the residual tensile stress σ_X lied in the final 2-3 passes, and the residual compressed stress σ_X lied in the first 2-3 passes. The residual stress σ_X which is in the initial stress zone on the top surface of pre-deformation substrate is higher than that of the substrate without pre-deformation after LSF, but the residual stress σ_X in the region far away from the initial stress zone on the top surface of pre-deformation substrate is low.