Simulation and experimental study of GGG70L laser quenching

GGG70L is a kind of cold-working die steel widely used in large automobile cover parts die. In order to ensure the life of the die, laser quenching process is usually used to form a certain hardened layer at a specific part of the die. In this paper, the changes of microstructure and hardness of ductile iron GGG70L after laser quenching were studied through a large number of process experiments, and the influence of quenching process parameters on the microstructure and properties of GGG70L was obtained. The relationship between the depth of hardened layer and the laser energy density is established and a quadratic function relationship was found between the two. It is found that both higher hardness and deeper hardening depth can be obtained when the energy density is 24-28 (J/mm2). The finite element model of the laser quenching process of GGG70L was established, and the temperature of the hardened zone and its evolution law during the laser quenching process were studied numerically.