Influence Of Laser Parameters On The Weld Quality Of 304l Austenitic Stainless Steel

Abstract

304L Austenitic stainless steel, a significant grade, boasts exceptional resistance to various chemicals and atmospheric conditions, making it versatile. Its low carbon content (≤ 0.03%) minimizes carbide precipitation during welding, enhancing its weldability. In addition, 304L maintains good strength and ductility, making it suitable for various applications such as food processing, chemical industry, and medical instruments. Consequently, traditional welding techniques, including metal inert gas (MIG) welding, are widely used to manufacture 304L austenitic stainless-steel components. However, these methods pose a higher carbide precipitation and distortion risk than laser welding. Therefore, this study employed Laser beam welding to optimize the weld quality and microstructure of 3.0 mm 304L austenitic stainless steel. The investigation began by varying the defocusing distance of -0.5 mm to 0.3 mm to obtain the optimal depth-to-width ratio, which was found to occur at -0.2 mm. Concurrently, the effects of process parameters, specifically laser power ranging from 2kW to 4 kW and welding speed from 1000 mm/min to 3000 m/min, were examined using a bead-on-plate technique and a butt joint configuration with a CO₂ laser beam. The results demonstrated that heat input is the primary factor influencing weld quality and thermal distortion, with the best performance achieved at a 4 kW laser power, a welding speed of 3 m/min, and a defocusing of -0.2 mm.  Additionally, increased laser power and welding speed significantly enhanced penetration depth while maintaining the optimal adverse condition under constant shielding gas. These findings offer valuable insights for optimizing laser welding parameters for industrial applications involving 304L Austenite stainless steel.