Microstructure and properties of Cr12MoV die steel by laser quenching with different power

Abstract In this paper, laser quenching on the surface of Cr12MoV cold-work die steel was carried out by CO2 laser. The laser scanning speed was 800mm/min, and the laser powers were 1200W, 1400W, 1600W and 1800W respectively. Thickness, microstructure, hardness, XRD, friction and wear properties of the quenched layer were investigated after laser quenching with different power. The results show that the thickness and martensite content in quenched layer increase gradually with the increase of laser power. The hardness of quenched layers have an increase firstly and a later decrease along with laser power. When the laser power is 1600W, the maximum hardness is 662.9HV. When the power is 1800W, microfusion appears on the surface, and the hardness of the quenching layer decreases. The wear volume of the sample first rises and then falls along with laser power. The minimum wear volume is 0.09mm3 at 1600W, and the wear volume is reduced by 92% of the original sample. Therefore, scanning speed of 800mm/min and laser power of 1600W can get the best microstructure and properties.