The Pulsed Yag Laser Welding of a Austenitic Steel Sheet to Decrease the Weld Distortion

Laser welding is frequently applied to process small precision parts since it has high power density and focuses beam spot size smaller. In an automobile industry, the laser welding has been put to practical use for welding of chassis because of its small weld distortion, the other hand, parts of motorcycle which are produced by laser welding are very few. Because most of the chassis and engine are made of aluminum alloys which are difficult to laser weld due to the low absorptivity of aluminum in the wavelength range of commercial laser welding system.(1)* However, the laser welding is applied for a part assembled with press-formed parts. Exhaust Ultimate Power Valve (EXUP), one of the exhaust system for 4-stroke motorcycles which has a precision valve system developed by Yamaha.(2)