Laser welding machine in the field of thin plate welding effect, but due to improper operation or process is not perfect, the welding process of porosity occurs from time to time, in order to solve this problem, first of all, to analyze the reasons for porosity, and then according to the reasons to give the appropriate measures to solve the problem. Laser welding machine in the field of thin plate welding effect, but due to improper operation or process is not perfect, welding process of porosity often occurs, in order to solve this problem, first of all, to analyze the causes of porosity, and then according to the reasons to give the appropriate measures to solve the problem.
The emergence of pores in the laser welding process is mainly due to the protection measures are not in place caused by the welding process, if the use of nitrogen-assisted welding, nitrogen from the outside into the molten pool, nitrogen solubility in liquid iron and nitrogen solubility in the solid state of iron has a great deal of difference, and thus in the cooling of the metal in the process of solidification; due to the nitrogen solubility with the decline in temperature and reduce the molten pool when the metal is cooled to the beginning of the crystallization. Solubility will occur a large sudden drop, at this time a large number of gas precipitation to form bubbles, if the bubble uplift rate is less than the metal crystallization rate, the generation of pores.
Laser welding hole in an unstable vibration state, small holes and the flow of the molten pool is very intense, small holes inside the metal vapor eruption caused by the opening of the small holes in the steam vortex, the protective gas into the bottom of the small holes, with the small holes moving forward, these protective gases will be in the form of gas bubbles into the molten pool. The use of argon gas for auxiliary welding, due to the low solubility of argon gas, laser welding cooling speed is very fast, the bubble is too late to escape and be left in the weld, the formation of pores. In the laser welding machine for processing, the laser welding machine needs to be blown along the fiber coaxial protective gas to prevent oxidation of the weld or to prevent the material from dissolving the gas splash contamination of the lens. The generation of porosity is mostly caused by improper use of shielding gas or operational errors during laser welding processing, and the causes of porosity are slightly different for different shielding gases.
Post time: 11-07-24
