A plasma arc welding device and process for ultrasonic assisted perforation

Abstract

The invention relates to a plasma arc welding device and process for ultrasonic auxiliary perforation. The process comprises the following steps that under the plasma arc welding condition, through tight coupling connection between an ultrasonic amplitude change rod and a tungsten electrode in a plasma arc welding gun, power ultrasonic vibration directly acts on a plasma arc by the tungsten electrode to strengthen a heat-force effect of the plasma arc. Meanwhile, part of ultrasonic vibration energy is transferred into a molten pool of a workpiece through the plasma arc to influence the heat transfer and flowing behaviors of the molten pool. Under the effect of the two aspects, compared with a general plasma arc welding process, the plasma arc energy density and stiffness are further improved, the plasma arc perforation capacity is improved, and the process parameter margin for obtaining excellent welding lines is widened. A welding joint obtained after welding is compact in structure, thorough in gas separation, refined in crystal grain, uniform in alloy element distribution and improved in mechanical performance of a joint.

Description

technical field [0001] The invention relates to a plasma arc welding device and process for ultrasonic-assisted perforation, and belongs to the technical field of high-efficiency plasma arc welding processes. Background technique [0002] Plasma arc welding (PAW for short) is an advanced welding technology with high energy density. For medium-thick steel plates, the perforated plasma arc welding can achieve one-time penetration and single-side welding and double-side forming without opening the groove. In the conventional plasma arc welding process, the small hole is sensitive to changes in process conditions; small fluctuations in process parameters may cause the small hole to close or the molten pool to collapse. The reasonable specification parameters for obtaining good joint quality are narrow and the adjustable margin is small. [0003] Power ultrasound has the characteristics of high frequency, strong penetrating ability, and the ability to change physical properties....

AI Technical Summary

Problems solved by technology

However, this method of using the arc as the source of ultrasonic generation requires the welding current to reach a frequency sufficient to generate ultrasonic vibrations, which has high requirements on the welding power source itself and poor adaptability; at the same time, the arc works in the heat conduction welding (melt-in type) mode , no small holes can be produced in the molten pool, and the base metal is penetrated by the heat conduction of the metal in the molten pool to achieve penetration

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