Alternating-current double-pulse MIG (Metal-Inert Gas) welding method for dissimilar metal welding of iron and aluminium

Abstract

The invention discloses a novel alternating-current double-pulse MIG (Metal-Inert Gas) welding method for dissimilar metals of iron and aluminium. The alternating-current MIG welding enables a base metal to be in a state with continuous change between a positive electrode and a negative electrode by power control, so that the heat input of the base metal in the welding process can be reduced, the thickness of fragile compounds between the metals of iron and aluminium can be reduced, and the mechanical property of welding joints is improved. Simultaneously, the alternating-current double-pulse MIG welding applies two types of pulses with different frequencies (one is high and the other is low) to current in the welding process; and due to the oscillation action of the double-pulse mode on a molten pool, the quantity of gas holes in an aluminium welding seam is reduced; and fish scales are formed on the surface of the welding seam, and the mechanical property of the dissimilar metal joints of iron and aluminium is effectively improved.

Description

technical field [0001] The invention relates to the field of arc welding metals, in particular to an AC double-pulse MIG welding method for welding iron and aluminum dissimilar metals. Background technique [0002] The current rapid development of the transportation industry has brought great convenience to people's lives. But at the same time, the large-scale use of aircraft and automobiles has led to the use of a large amount of fossil fuels, which has aggravated the pollution of the environment. Therefore, in order to achieve the goal of sustainable development, choosing light metals instead of heavy metals and reducing the weight of the vehicle as much as possible on the premise of ensuring mechanical properties can effectively improve the efficiency of fossil fuel use and reduce greenhouse gas emissions. Due to its excellent mechanical properties, aluminum alloy can partially replace steel as a frame structure, so welding aluminum alloy and steel can obtain good compre...

AI Technical Summary

Problems solved by technology

The mechanical properties of the joint obtained by friction welding are better, but the size and shape of the joint will be limited

Laser welding and arc welding have a wide range of applications, but the heat input of these two types of welding is relatively large, which will cause a thick layer of brittle intermetallic compounds at the iron-aluminum interface, which will affect the mechanical properties of the joint

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