부산대학교 도서관

A new method of improving the fatigue strength of the steel wire for automobile have been developed. Principle of the new method is thin surface layer annealing of the wire by using the high power density zone of the focused laser beam in the cone shaped focusing mirror.In this method, the laser beam was coaxially irradiated and focused on the wire to anneal it uniformly. Using this laser processing technique, up to 3μm depth of uniform annealing has been realized, which results in degrading the tensile strength. No defect was observed on the annealed surface of the wire. It should be possible to realize the effective manufacturing process of high performance steel wires using this method.