In today's rail transit, shipbuilding and other industries, there is an increasing demand for welding of medium and large thickness steel plates. In recent years, in order to promote the development of my country's shipbuilding industry, the country has successively issued policies that prioritize the development of high-tech ships and high value-added ships, and accelerate the transformation and upgrading of the shipbuilding industry, and the trend of world shipbuilding is also developing towards large-scale, diversified, and high-grade development. Welding technology is a key technology in ship processing and manufacturing and the development of the shipbuilding industry. Welding man-hours account for about 30% to 40% of the total man-hours for shipbuilding. Welding production efficiency and welding quality directly affect the production cycle, cost and hull quality of ship processing and manufacturing. Therefore, high-efficiency and high-quality ship welding technology is an important factor in the transformation and upgrading of my country's shipbuilding industry, and it is also an important factor in improving the international competitiveness of my country's shipbuilding enterprises.
In addition, with the rapid development of my country's railway train industry and the continuous speed increase of trains, bogies, which are important components of rail vehicles, carry greater dynamic loads. This puts higher requirements on bogie technology. Bogies are in the design , Materials and processes must be continuously developed and improved to meet the performance requirements. The quality of welded joints has become one of the important links to ensure the quality of the bogie frame. Therefore, a more optimized welding method is a necessary condition.
Laser-arc hybrid welding emerges as needed
As a new welding technology, laser-arc hybrid welding uses laser and arc as dual heat sources and acts on the same molten pool at the same time to form laser guidance and stabilize the arc. The arc increases the metal’s absorption rate of the laser and enhances the droplet transfer bridging. A kind of welding method of ability, give full play to the advantages of laser welding and arc welding, and make up for their shortcomings. Especially in the welding of medium and large thickness materials, hybrid welding technology has greater advantages. Because traditional welding methods have disadvantages such as low joint strength, low efficiency, serious deformation, and large consumption of welding materials; and the use of single laser welding also has some shortcomings, such as high joint assembly process requirements and welding ability restricted by laser power Large, poor bridging ability, serious weld undercut, etc.
As a new type of welding method, laser-arc hybrid welding has the following three notable characteristics:
1) Improve energy utilization, increase the one-time penetration depth and welding speed of the weld;
2) Reduce the assembly requirements of the workpiece;
3) Improve the quality of welds and improve weld forming;
Laser-arc hybrid welding can realize 1＋1＞2
There are many forms of laser-arc hybrid welding, including Laser-MAG/MIG hybrid welding, Laser-TIG hybrid welding, laser-plasma arc hybrid welding, etc. The commonly used laser light sources at this stage are fiber lasers and semiconductor lasers. For example, Raycus continuous fiber laser 4000W, 6000W and fiber output semiconductor laser 4000W.
