A low back pressure penetration arc welding device and method

Abstract

The invention relates to a low back pressure penetrating arc welding device and method. The central negative pressure cavity of the low back pressure protection device is exhausted by an air extraction device, so that the tail flame of the penetrating arc located in the central negative pressure cavity And the back of the perforated molten pool is in a negative pressure state with an argon atmosphere, so that the perforated molten pool forms a pressure gradient from the front of the molten pool to the back, further enhancing the stiffness and arc stability of the penetrating arc on the front of the molten pool, and The piercing ability of the piercing arc is improved without changing the force distribution and temperature gradient on the front of the piercing molten pool. The welding device and method not only greatly increase the weldable thickness of the conventional penetration arc welding process, but also improve the formation of the back side of the weld seam for perforation welding by maintaining the negative pressure state on the back side of the molten pool.

Description

technical field [0001] The invention relates to a low back pressure penetrating arc welding device and method, belonging to the field of welding technology. Background technique [0002] With the development of modern industry towards large-scale structures, the welding structure of medium and ultra-thick plates is more and more widely used. Therefore, the requirements for welding methods are also getting higher and higher. Traditional welding methods have been difficult to meet such requirements. welding requirements. For the manufacture of thick-walled metal structures such as pressure vessels, boilers, rails, ships, and large-scale engineering construction site operations, a large number of thick-plate joints generally use large-groove multi-layer multi-pass MAG / MIG welding or submerged arc welding. With the continuous increase of plate thickness, the above methods have shown great limitations and inapplicability. The most prominent performance is that due to the sharp ...

AI Technical Summary

Problems solved by technology

However, as the thickness of the welded plate increases, the requirements for the penetration ability of the plasma arc are also higher and higher, and the tendency of small hole instability increases. It is extremely important to find a better balance between heat input and stable forming of small holes. Difficult, when the thickness of the workpiece to be welded reaches a certain value, the plasma arc will not be able to penetrate the workpiece to be welded

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