Study On Rollers Surfaces Laser Treatment And Numerical Simulation

Rollers, which work under rigourous condition and endure impaction, grindness and heat fatigue, are important components in rolling. By enhancing the life of rollers, the expendation of rollers and their swap frequency can be reduced, while their efficiency can be improved. With the boom of laser hardening technology, it is also commonly adopted in rollers surfaces hardening. Rollers laser surfaces hardening involves rollers laser surfaces quenching, laser melting, and laser alloying, in which the first two are widely used. Rollers surfaces hardening has its unique advantage.Seven sorts of rollers are treated by laser hardening and melting technologies. The paper uses the FEA software to simulate the temperature field of rollers surfaces during hardening, and the results meet the experiment measurement quite well.(1)75CrMnMo and 70Mn2 rollers acquire good results after laser melting treatment, the depths of the hardening zones are up to two millimeters and the microhardness of the zones is greatly increased. (2)The hardness of High-Chromium contained steel can be improved from HV550 to HV750-800 after laser treatment, and the peak microhardness may reach HV900. The antigrindness is correspondly improved.(3)The difficulty to harden high-Carbon- Chromium contained iron is caused by the melting zone, which may bring two problems: tiny cracks and low hardness of residual austenite. Liquid nitrogen cryogenic processing, low temper, laser treatment parameter control are all desirable methods to lessen or eliminate the low hardness zone.(4)Alloy-contained rollers show satisfying rules after laser treatment, and the antigrindness homologize with the microhardness trend. (5)High-Nickel-Chromium contained cast irons have very high Carbon containment (about 3.2%) and low melting point(about 1350℃), which makes it be sensible to laser treatment parameters.(6)Low melting point of half-steel rollers leads to the easily building of melting zone and the low microhardness of them. The microhardness of melting zone is low, while the microhardness of hardening zone is relative high, which may be up to HV800.(7)Using the second exploitation language, the automation of solution is realized. The dynamic change course under the given laser parameters and the distribution of the temperature field are researched, and the simulation results are perfect.(8)The effects how laser power, scanning velocity, laser diameter, and laser power density on the depth of hardening are studied.