INFLUENCE OF WELDING PARAMETERS ON WELD BEAD GEOMETRY IN LASER BEAM WELDING OF CARBON STEEL ST 37

Abstract

Laser beam welding (LBW) is a non-conventional joining technology widely used in industry due to its advantages, such as a small heat-affected zone (HAZ) and high precision. Welding quality is influenced by several parameters, including welding speed, shielding gas flow rate, and the distance between the components being welded. This study aims to investigate the influence of welding parameters on weld bead geometry and HAZ in the laser beam welding of carbon steel St 37, without filler material. The paper demonstrates the importance of optimizing welding parameters to achieve a high-quality weld in carbon steel St 37. Laser welding experiments were conducted using an XT Laser 1.5kW Handheld Fiber Laser Welding Machine, mounted on a monoaxial automatic displacement device. Welding parameters such as welding speed, argon flow rate, and distance between the welded plates were varied, while keeping other parameters constant. The dimensions of the welded bead and HAZ were measured on cross-sections of the welded specimens. The experimental results showed that the dimensions of the weld bead and HAZ increase with decreasing welding speed and increasing argon flow rate. The distance between the welded plates negatively influences the shape of the bead; an excessive distance leads to a concave bead profile with reduced mechanical strength. These findings emphasize the need for precise control of welding parameters to achieve high-quality joints.

Keywords

• Laser welding
• Carbon steel St 37
• Welding parameters
• Bead size
• Heat-affected zone (HAZ)
• Manual laser