High Power Diode Laser (HPDL) surface hardening of low carbon steel: Fatigue life improvement analysis

In the present investigation, a high-power diode laser was applied to improve the fatigue life of AISI 1040 steel components. The interaction between the laser radiation and the steel surface was studied, and the effectiveness of the laser treatment was analysed by fatigue testing. First, the importance of each of the following laser operational parameters was assessed: power, scan speed, focus and number of passes. Second, rotating bending fatigue tests were performed to investigate the effects of laser treatment and the influences of the laser operating parameters on the fatigue endurance of the components. Wohler curves, determined from an analysis of the experimental results, showed that laser treatment can significantly increase the fatigue life of irradiated components, thus revealing the suitability of this method for industrial applications.