In-Situ investigation of Residual stress and Crystallographic Texture Evolutions of 17-4 PH Stainless Steel during High temperature Annealing

The 17-4 PH stainless steel has wide range of applications in power plants, marine, and chemical industries due its good mechanical properties and corrosion resistant. Although, producing 17-4 PH alloy via Additive Manufacturing (AM) technology has great advantages, numerous undesired results encountered. During selective laser melting (SLM) process, high temperature gradient can be generated within the AM produced part as a results of high energy input at local scanning points leading to increased residual stresses. Furthermore, the residual stresses promote premature failures of the mechanical parts used in services. Therefore, it is critical to investigate the residual stresses generation during 3D printing and understand the recovery mechanism during post processing heat treatment. The SLM scanning strategy parameters have a great influence on the generated microstructure, texture and post fabrication treatments. Therefore, it is important to investigate the SLM scanning strategy and post processing parameters influences on residual stress generation and texture evolution. Here we will particularly focus on understanding the effect of different 3D printing scanning path and post processing parameters. Each of these scan paths will result in a different residual stresses distribution and microstructure/texture evolution during printing and post processing.