Influence of laser hardening modes on the properties of 40X13 steel

Abstract

We have studied the dependence of the characteristics, strength and plasticity, as well as the microhardness of specimens made of corrosion-resistant steel 40X13 on the modes of laser surface hardening by a fiber laser. Depending on the size of the scanning spot and the scanning speed, 3–5 tracks were applied on opposite planes of the sample with overall dimensions of 20 × 200 mm. Samples were tested for static fracture and the microhardness of the material of the samples was studied in terms of the depth of the changed structure. It was found that the fracture of the treated samples in all cases was of a brittle nature with a low level of destructive deformations at stresses below the tensile strength of the original material. The plotted tension diagrams indicate an insignificant effect of laser processing on the value of the elastic modulus of the material. Studies of the hardness of the material of the laser-hardened track and the microhardness of the material along the depth of the zone of the changed structure showed their increase up to 3–4 times compared with the initial characteristics. The results obtained can serve as a basis for studying the relationship between the modes of heating by a laser beam and the properties of the material of the hardened zone.