Numerical Simulation Of The Thermal-force Field And Optimization Of The Solution Efficiency Of The Special Stainless-steel Laser Powder Bed Fusion Process

There is a special martensitic stainless steel prepared by laser powder bed fusion(LPBF),which has been widely used in the field of aerospace and defense due to its excellent performance,but due to the influence of thermal stress,the LPBF preparation process and after printing may crack warpage and other phenomena,resulting in printing defects or even printing failure,the causes and influencing factors are not clear;the use of finite element analysis method to study the complex physical process of LPBF Based on this,this paper establishes a numerical model for the evolution of the temperature and stress field of LPBF of this special martensitic stainless steel by using the finite element analysis software ANSYS.The effect of process parameters on the temperature field stress field is also investigated;meanwhile,the efficiency of the numerical simulation of the LPBF temperature field stress field is improved by means of heat source replacement,and the computational resources and time consumption of the numerical simulation are reduced.The main results of this study are as follows:(1)The temperature field stress field evolution law of the LPBF process of this special stainless steel is clarified,the influence of process parameters on its temperature field stress field is studied,and the influence law of different process parameters on the temperature field stress field is derived,which provides guidance for the process regulation of residual stress in the LPBF process.(2)By replacing the moving Gaussian heat source equation with a simple heat source equation of low order,the number of instanton equations for LPBF process temperature field stress field simulation is reduced,the number of steps and step length of finite element analysis are reduced,and the efficiency of LPBF process temperature field stress field simulation is improved under the premise that the temperature gradient and stress distribution are similar.(3)The reliability of the LPBF simulation was verified in terms of the melt pool shape and the residual stress.The numerical simulations in this paper have achieved the purpose of guiding the LPBF process parameters to some extent.