Parameter optimization and mechanical properties of 42CrMo4 manufactured by laser powder bed fusion

Abstract To study the manufacturability and mechanical properties of a low alloy heat treatable medium carbon steel by additive manufacturing, 42CrMo4 (AISI4140) specimens were manufactured laser powder bed fusion. Influences processing parameters on relative density crack investigated. Moreover, Charpy impact tests, microhardness, tensile tests for with without preheating also studied. Results showed that primary defects in microstructure additively samples lack fusion pores microcracks. The variation influences porosity microcracks prominently. toughness is around three times higher than preheating. However, post treatment as-built specimens, such as tempering at different temperature ranges, did not improve further. detailed fracture mechanism massive difference was