A Study on the Shot-Peening Effect for Fatigue Life Improvement of Laser Welding Material

At present, welding technology is not only emphasized in the development of manufacturing technology but its application is also expanding. In these systems, attempts have been made to use SUS as a high-temperature material for special applications, and in improvements in manufacturing technologies bear watching, together with an increase in the use rate. Specifically, three-dimensional wings are often used for fasteners with the purpose of decreasing the weight (정해용, 2007). However, due to developments in welding technology, there has been a recent tendency to replace existing assembly methods with welding. Specifically, if laser welding techniques are applied, the heat-affected zone can be minimized compared toother welding techniques. However, in the case of these special welding techniques, there is an increase in residual stress, which fatally affects the fatigue life. In order to remove the residual stress and its effect on fatigue life, shot-peening is executed. The intention of this study was to obtain the optimal conditions for shot-peening.