Laser Transformation Hardening And Hardened Layer Depth Research

Laser transformation hardening is a changeable process of a transient temperature field, the laser transformation hardening layer depth has a good performance that is thin and has stable compressed stress. Under the same intensity, the laser transformation hardening layer depth can be thinner than regular heat treating depth. However, in the practice, people have special request on the laser transformation hardening layer depth, they respect the laser transformation hardening layer depth can be deeper. The paper will do more research on the deepest depth of the laser transformation hardening layer.According to the basic theory of the laser transformation hardening, in view of rectangle shaped physics model, based on 45~# steel to set the physical property coefficients, using ANSYS to simulate the 3-dimensional temperature field associated with laser transformation hardening. Through the process of the exact 3-dimensional analysis model, loading, solving, post-processing, the 3-dimensional temperature field of the laser transformation hardening will be directly expressed, the node temperature of the model will be exactly brought out. All section depth of the laser transformation hardening layer can be effectively calculated. So it provides an efficient solution to research the parameter of the deepest depth of the laser transformation hardening layer.Based on the fixed laser light spot, using the relational curve of the laser power and the scanning speed under the critical melting condition, pick up the match value and the parameter around the match value of the laser power and the scanning speed on the relational curve, combined the ANSYS to simulate the 3-dimensional temperature field with this series laser parameters. Through the 3-dimensional simulation, the temperature field associated with laser transformation hardening reflect the real condition of the temperature field associated with laser transformation hardening in different time. It proves that the element analysis simulation of the laser transformation hardening layer basically conforms to the real condition, and it brings out the parameter range of the deepest depth of the laser transformation hardening layer based on the fixed laser light spot.For the research of the 45~# steel laser transformation hardening, it brings out the influence of the laser transformation hardening layer depth caused by laser power and scanning speed, the optimal laser parameter under the fixed depth, and it also brings out the 45~# steel laser parameter range of the deepest depth of the laser transformation hardening layer under the fixed laser light spot. It considers the influence of the laser transformation hardening to the details of the organization. It also describes the influence of the surface coating to hardening layer depth.Based on the deepest depth of the laser transformation hardening layer, it researchs the influence of the hardening layer depth caused by laser light spot under the critical melting condition. It shows that wide-band laser can bring out the deeper hardening layer depth than the ordinary narrow laser. As to the different wide-band laser, while the more narrow wide-band laser can obtain the deeper laser transformation hardening depth.