Consumable electrode pulsed arc welding method and welding equipment

Abstract

The invention provides a consumable electrode pulsed arc welding method and welding equipment. The method comprises the steps of feeding a welding wire, and performing welding through a first stage and a second stage which are alternately used; in the first stage, switching on an electrode positive polarity current, and performing short-circuit transition welding by the positive polarity current; and in the second stage, switching on the electrode negative polarity current, wherein the negative polarity current is a negative pulse, and enabling electric arc to climb from the end of a welding wire along the welding wire by adopting the negative pulse and to be attached to and clean the surface of the welding wire. The electric arc can climb along the welding wire through the negative pulse, an oxidation film and oil stains on the surface of the welding wire are removed, the porosity is greatly reduced, and the welding quality is improved.

Description

technical field [0001] The invention relates to the field of melting electrode arc welding, in particular to a melting electrode pulse arc welding method and welding equipment. Background technique [0002] In actual welding, carbon steel, stainless steel, and aluminum alloy welding will be subject to high porosity due to poor wire surface quality, especially aluminum alloy welding. Take aluminum alloy welding as an example: at present, arc welding and friction stir welding are mainly used for welding aluminum alloys in the market, and the proportion of arc welding is very high. The problem of porosity in arc welding has always been a problem that plagues the industry, especially MIG welding. , High porosity is a common problem in the aluminum alloy industry. Because of the physical characteristics of aluminum alloys such as low melting point and fast heat conduction, it is difficult for the pores to escape quickly during the welding process of aluminum alloys and stay in th...

AI Technical Summary

Problems solved by technology

Take aluminum alloy welding as an example: at present, arc welding and friction stir welding are mainly used for welding aluminum alloys in the market, and the proportion of arc welding is very high. The problem of porosity in arc welding has always been a problem that plagues the industry, especially MIG welding. , High porosity is a common problem in the aluminum alloy industry. Because of the physical characteristics of aluminum alloys such as low melting point and fast heat conduction, it is difficult for the pores to escape quickly during the welding process of aluminum alloys and stay in the weld, becoming a potential hidden danger. The strength of the weld, and usually the base metal is cleaned before welding to ensure the gas purity to reduce the source of pores, but in fact no matter how clean the base metal is, no matter how pure the gas is, the pores still cannot be eliminated, and even exist all the time. Influenced by the surface of the welding wire, lubricants will be properly used during the production process and storage of the welding wire to prevent oxidation and rust, and these lubricants will just become another source of pores. This invention is to solve the dirt on the surface of the welding wire , reduce weld porosity

[0003] Although AC welding aluminum alloys have been used for a long time, TIG welding mainly uses AC, and MIG welding is rarely used. Therefore, the previous AC arc welding aluminum alloys also have the effect of cleaning oxide scales, but there is no specific treatment for the oxide scales on the surface of the base metal. The oxide scale on the surface of the welding wire is cleaned and controlled. By designing a new welding waveform, the arc reverse polarity is used to regularly clean the oxide film of the welding wire, and a section of the transition section is cleaned to form a virtuous cycle of cleaning before the transition and control the arc during the transition period. arc length, to ensure that no oxidizing components such as oil stains form pores during the welding process

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