Central pulsation negative-pressure arc welding device and method

Abstract

The invention relates to a central pulsation negative-pressure arc welding device and method, and belongs to the technical field of welding equipment and methods. An inner cavity of a hollow tubular electrode and the center of an arc below the hollow tubular electrode enter a periodic negative-pressure state by virtue of an air extraction device, and when the center of the arc is in a normal-pressure state, the arc is in a free arc form; when the center of the arc is in a negative-pressure state, the arc is in a restrained state under the compression action of external atmospheric pressure; therefore, the arc is switched between a free arc and a restrained arc to implement the central pulsation negative-pressure arc welding method. The pulsation arc produced by the welding device and method has oscillation and stirring functions for a welding pool, so that liquid metal forms tiny isometric crystals, the formation of air holes is suppressed, and the mechanical performance of a welding joint is improved; the pulsation frequency and duty ratio of the arc are regulated to accurately control the oscillation and stirring of the welding pool, the welding penetration and heat input.

Description

Technical field [0001] The invention relates to a central pulsating negative pressure arc welding device and method, and belongs to the technical field of welding equipment and methods. Background technique [0002] Since the development of welding technology, the goal pursued is high quality, high efficiency and high speed. As the most complicated process in the welding process, the welding pool has an important influence on welding quality, welding efficiency and welding speed. The shape and behavior of the weld pool are often also important factors for welding defects, such as porosity, slag inclusion and welding cracks. The crystallization process of the weld pool affects the quality of the weld and the mechanical properties of the welded joint. Because the crystallization process of the weld pool is very complicated, it is easy to form thick columnar dendrites, which affect the mechanical properties of the weld. Therefore, controlling the crystallization of the weld pool ...

AI Technical Summary

Problems solved by technology

The point of view is: on the one hand, during the ultrasonic propagation process, part of the energy is absorbed by the liquid and converted into heat energy, which leads to the attenuation of the ultrasonic amplitude, and forms a sound pressure gradient from top to bottom in the molten pool, resulting in a higher temperature in the molten pool The liquid metal flows to the bottom of the molten pool at high speed, increasing the welding penetration

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