As a new type of material, wear-resistant plate has been widely used in aerospace, auto parts and other fields by virtue of its own characteristics of wear resistance and formability. The application of laser welding in wear-resistant plates occupies a very important position, especially in the automotive industry, and the body is all connected by welding. However, affected by many factors, wear-resistant plate welding has deformation problems, and the control is difficult, which is not conducive to the sustainable development of related fields. Therefore, it is of great significance to strengthen the research of laser welding deformation of wear-resistant plate.
1. Overview of laser welding
Laser welding mainly refers to a welding method that uses laser as a heat source to melt and connect the workpiece. In the process of laser welding, the laser illuminates the surface of the material to be welded, acts on it, and part of it is reflected and the rest is absorbed, entering the inside of the material to complete the welding goal. In short, the process of laser welding is to use a high-power laser beam after the optical system is focused, irradiate to the surface of the material to be welded, and then make full use of the material to absorb the light energy for heating and other processing, and finally form a melting welding process after cooling. Under normal circumstances, laser welding is mainly divided into two categories: thermal conduction welding and deep penetration welding.
2. The harm caused by welding deformation and the main factors affecting welding deformation
The main factors affecting welding deformation are welding current, pulse width and frequency distance. With the increase of welding current, the width of the weld also increases, and spatter and other phenomena gradually appear, resulting in oxidation deformation of the weld surface and a rough feeling; When the pulse width increases, the strength of the welded joint increases. When the pulse width reaches a certain extent, the heat conduction energy consumption of the material surface also increases, and the liquid spills out from the weld pool due to evaporation, resulting in a smaller cross-sectional area of the solder joint, which affects the strength of the joint. The influence of welding frequency on the welding deformation of wear-resistant plate is closely related to the thickness of steel plate. For example, for 0.5mm wear-resistant plate, when the frequency reaches 2Hz, the weld overlap rate is higher. When the frequency reaches 5Hz, the welding seam burns seriously, the heat affected zone is wide, and deformation occurs. Thus, it is imperative to strengthen the effective control of welding deformation.
