Laser welding process evaluation on stake-welded T-joints

Ship structural steel EH36 sheets with thickness of 3 mm were stake-welded with T-joints by using fiber laser beam welding (LBW). Optical microscope (OM) observation, angular distortion measurement and tensile test were conducted to investigate the influence of defocusing distance, welding speed and line energy on the joint properties. The experiment results showed that laser stake-welded T-joints with high quality could be obtained at 1.8 m min(-1) speed high, -5 mm defocusing distance and 5 kW power. The loss of liquid metal in the misalignment condition led to severe underfill. In addition, laser line energy and misalignment contributed significantly to welding angular distortion. The welding width between face panel and web panel exerted an important influence on the tensile properties. Moreover, the thermal distortion process induced by fiber laser welding has been schematically illustrated and systematically revealed.