technical know-how
Laser welding - a shining light of precision
Laser welding is a modern method for joining stainless steel and other metals in the automotive, aerospace, and electronics industries. It is effective because it can overcome the challenges of the physical properties of these metals, such as stainless steel’s high melting temperature and low thermal conductivity.
Laser welding is a popular production method for stainless steel structural profiles by welding individual components together, such as flat laser cut strips, prefabricated solids, hollows, or other shapes. Despite the advantages in precision, speed and material protection, laser cutting and welding were used in niche applications for a long time. A notable spread of systems for laser cutting and laser beam welding did not take place until the mid-1980s. Before that, these systems were only used in research institutes and specialist companies. Firing up fusion Today, laser welding remains a non-standard welding process. In South Africa sheet metal processors are increasingly relying on this high-tech process, which continues to impress with its efficiency, quality, and precision. Laser welding (also known as laser beam welding) is a process that uses a concentrated heat source, in the form of a laser, to melt the materials. They then fuse as they cool down. It is a versatile process as it can thin materials at rapid welding speeds while running narrow and deep welds for thicker materials. The main advantages of laser welding
are its high precision, since the laser beam focuses on a small area, resulting in minimal distortion and a high- quality weld. Of importance is the fact that the focused laser beam delivers high energy density to the workpiece, allowing for rapid melting and solidification. The laser beam penetrates deeper into the medium compared to other welding methods and therefore limits the potential for cracking after autogenous welding. The process also features disadvantages such as the high cost of entry- level laser welders. The laser beam also has limited penetration depth and suffers from limited weld joint access. Data is limited, but a reduced weld strength has been reported when using laser welding. Inert welding gases that are suitable for laser welding include helium, argon, and argon/helium mixtures. Argon is the preferred shield gas for welding certain grades of stainless steel. It’s inert, has high thermal conductivity, and offers excellent arc stability. Argon suppresses plasma, which prevents unwanted sparks and ensures a stable welding arc. Argon’s density is also larger, which is favourable for sinking above the weld pool and better protecting the weld pool.
25
Issue 1– 2024
Made with FlippingBook - professional solution for displaying marketing and sales documents online