Investigating the effects of the laser quenching technology on the hardness and microstructure of P18 steel

The article introduces laser quenching technology and presents the results of surveying the hardness and microstructure of P18 steel sample after laser quenching. Laser quenching is a new candidate technique for having precise heat treatment, limiting warping, saving energy, and being environmentally friendly compared to traditional quenching. Before quenching samples (laser quenching or normal quenching), the φ22 mm diameter x 20 mm thickness samples were sequentially ground by abrasive papers with a grit size of #240, 400, 600, 1000, and 1200. This study aimed to investigate the influence of laser quenching power and traditional quenching on the hardness and microstructure of P18 steel... The microstructure and microhardness were observed by the Axiovert 40 MAT optical microscope and the Future Tech Corp FM-700e hardness tester, respectively. The results showed that the quenched sample hardness with a laser source power of 300, 500, 700, and 900 W are 280, 450, 940, and 1050 HV0.1, respectively, and compared to the traditional harden, it only reaches 650 HV0.1. Observation of the microstructure of the laser-hardened sample in cross-section, including a bright white high-hardness region and a dark transition region.