Abstract
SAE 9260 spring steel specimens after enduring 50% of their mean fatigue life were subjected to laser shock peening using an in-house developed 2.5J/7ns pulsed Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser for studying their fatigue life enhancement. In the investigated range of process parameters, laser shock peening resulted in the extension of fatigue life of these partly fatigue damaged specimens by more than 15times. Contributing factors for the enhanced fatigue life of laser peened specimens are: about 400μm thick compressed surface layer with magnitude of surface stress in the range of −600 to −700MPa, about 20% increase in surface hardness and unaltered surface finish. For laser peening of ground steel surface, an adhesive-backed black polyvinyl chloride (PVC) tape has been found to be a superior sacrificial coating than conventionally used black paint. The effect of repeated laser peening treatment was studied to repair locally surface melted regions and the treatment has been found to be effective in re-establishing desired compressive stress pattern on the erstwhile tensile-stressed surface.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
