Laser heat treatment effect on fatigue of hinged cantilever beams

Abstract

The paper considers the effect of laser hardening treatment of steels on the fatigue strength of materials. The statement of efficiency of laser processing for formation of hard surface layer of processed surface which protects from wear is substantiated in relation to a hinge design in agricultural machines placed on a cantilever fastened beam which is a hinge axis. The phenomenon of reduction of fatigue characteristics of structural steels after laser treatment is investigated. Influence of fatigue loading on beam durability is analyzed. On the basis of experimental data analysis, the conclusion is formulated that the surface defects in the form of wells which are formed under the influence of laser pulse play an important role during the pulse laser treatment. Particular attention is paid to the role of residual stresses generated by the thermal effects of the laser. On the basis of this research, it is recommended that laser hardening treatment should be carried out, the pulse energy of which does not lead to surface melting.