Study of thin plate 012A1 die steel during pulsed Nd: YAG laser melting

Laser melting of thin plate, made of 5Cr4Mo3SiMnVAl(012Al) die steel with thickness of 0. 8mm, was carried out by the use of pulsed Nd: YAG laser. The changes in phase and chemical composition of laser-melted zone were evaluated by using XRD, TEM and EPMA methods. The results show that although the phases of 012Al die steel before and after pulsed Nd:YAG laser melting are α-Fe(Martensite) and γ-Fe(Austenite), the position of X-ray diffraction peak and the volume of remained austenite are different. The particles of AIN impurity, V₄C₃ carbide, Mo₆C carbide with a long plate shape, and the plate-like martensite are existed in the laser-melted zone. The distribution of alloying elements in the laser-melted zone is high chemical homogeneity.