Residual stress distribution in Inconel 625 superalloy samples obtained from the selective laser melting (SLM) process using the finite element method

Additive manufacturing methods have become very popular in recent years due to their many capabilities, including the optimal use of materials and their use in constructing complex structures. One of the most important methods in these processes is the selective laser melting (SLM) process. In previous research, measuring the residual stress distribution of Inconel 625 samples under the SLM process has not been investigated. Therefore, in this research, the SLM process was carried out on the Inconel 625 sample using the finite element simulation method, and then the residual stress distribution in the sample obtained from the process was investigated in three main directions. Also, the formation of the molten pool, its dimensions, and temperature distribution were investigated. The results showed that tensile residual stresses were formed in the center of the layer and compressive residual stresses were more present at the edges of the sample. Also, the maximum of the residual stresses were formed in the axial direction and their minimum appeared in the layer thickness direction. The results related to the effect of process parameters on the residual stress distribution showed that with increasing laser power, tensile and compressive residual stresses increase in both axial and hoop directions, but decreasing the scanning speed does not give us accurate information about the increase or decrease of these stresses. For validation, the results of the finite element method were compared with the results of other researchers. The obtained difference was 13.97%. Therefore a good agreement existed between them.