Laser quenching process parameters are a key link in laser heat treatment. The process parameters mainly include laser power, laser beam scanning speed, focal length of the focusing mirror, and defocusing amount (distance between the quenched surface and the beam focus). The energy absorbed by the quenched surface depends on the laser power; The action time of the laser beam on the quenched surface depends on the scanning speed; The size of the spot depends on the focal length and defocusing amount of the focusing mirror; The laser power density depends on the laser power and spot size. Generally, an increase in laser power results in an increase in the depth of the quenched layer; The scanning speed increases, and the depth of the quenched layer decreases; As the defocusing amount increases, the size of the light spot increases, and within a certain range, the width of the quenching layer increases.

Laser heat treatment, also known as laser quenching or laser phase transformation hardening, is a process in which a high-energy laser beam is used to quickly scan the workpiece, causing the surface temperature of the irradiated metal or alloy to rise above the phase transformation point at an extremely fast rate. When the laser beam leaves the irradiated area, due to thermal conduction, the cold substrate rapidly cools down and undergoes self cooling quenching to obtain a finer hardened layer structure, with a hardness generally higher than that of conventional quenching.