The study of laser deep penetration processing on prefabricated cracks of high carbon steel

This paper describes the testing of laser deep penetration processing on controlled fragmentation of high carbon steel (50SiMnVB). The objective of this research is to make use of defects in deep penetration zones and optimize the quality of prefabricated cracks. The research shows that a deeper central crack appear in the deep penetration zone when the heat input is 60 J/mm, and the appeared crack is affected by martensite in microstructure, high microhardness and a high magnitude of tensile stress. Furthermore, the fracture mode of the deep penetration zones is mixed-mode (ductile and brittle fracture).