Study on Microstructure and Mechanical Properties of Cr12mov Alloy Deposited by Laser Melting Deposition

The deposition samples of Cr12MoV with different scanning speeds are prepared by laser melting deposition technology. Compared with forged Cr12MoV, the mechanism of laser melting deposition technology to improve hardness and wear resistance is studied. The tensile specimens of as‐deposited Cr12MoV are prepared by using the optimal process parameters. The fracture mechanism of as‐deposited Cr12MoV and the effect of deposition direction on its mechanical properties are studied. The phase composition and microstructure of deposited and forged samples are studied by X‐Ray diffractometry (XRD) and scanning electron microscope (SEM). The results show that the martensite in the as‐deposited Cr12MoV sample increases and has a finer grain size, which achieves the effect of fine‐grain strengthening. The hardness and wear resistance of the deposited Cr12MoV samples at three laser scanning speeds (4, 8, and 12 mm s−1) are better than those of the forged samples. The tensile fracture mode of the deposited Cr12MoV sample is an intergranular brittle fracture, and the sample perpendicular to the laser scanning speed has higher tensile strength and more excellent elongation. The main purpose herein is to study the differences of microstructure, microhardness, friction, and wear properties between forged and laser melting‐deposited Cr12MoV samples. The tensile behavior of as‐deposited samples is studied. The results show that the laser melting deposition technology can refine the crystallite, and the fracture behavior of the deposited Cr12MoV sample is an intergranular brittle fracture.