31 / 2021-06-28 10:03:49

Study on laser surface hardening process of 30CrMnSiNi2A ultra-high strength steel fabricated by laser deposition manufacturing

Laser surface hardening process, 30CrMnSiNi2A, Surface morphology, Wear resistance

Laser surface hardening is one of the effective method to enhance the mechanical properties of localised surface area of engineering parts made of different types of steels and other metals like ultra-high strength steel etc. Laser surface hardening has many advantages over conventional hardening process like, self-quenching, very fast, control over energy input and localised hardening etc. In order to further improve the surface quality and mechanical properties of 30CrMnSiNi2A ultra-high strength steel parts fabricated by laser deposition manufacturing (LDM). The quenching modified layer was prepared on the surface of 30CrMnSiNi2A steel by laser quenching technology. This work presents the effect of different laser parameters on the surface morphology and mechanical properties of 30CrMnSiNi2A steel after laser hardening. The experimental data of OM morphology, microstructure, micro-hardness and wear property of hardened layer were analyzed by using the methods of range analysis. The experimental work was carried out using 100W nanosecond (ns) pulsed laser quenching system. Laser power, laser scanning speed, defocusing amount and hatch spacing were the process parameters used for the experiments. Effects of these parameters over the micro hardness of the surface are described. It has been found that, there is around 25% increase in hardness after laser hardening. It considerably debased the surface roughness and wear rate of LDM 30CrMnSi2A alloy parts, which has decreased by 48% and 57% than without laser surface hardening parts. Accordingly, industrial applications of laser deposition manufacturing 30CrMnSi2A alloy parts were supposed to be widened by this study.