Split type high-order laser beam based tailor welding method for automotive aluminum-silicon coated steel plates

Abstract

The invention discloses a split type high-order laser beam based tailor-welding method for automotive aluminum-silicon coated steel plates. The method comprises the following steps that 1, the two aluminum-silicon coated steel plates are fixed with a tailor-welding gap of 0.3-0.4 mm; and 2, in the protective gas atmosphere, split type high-order laser beam laser wire filling welding is adopted, a split type high-order laser beam is a high-order laguerre-gaussian transverse mode laser beam, and the order comprises TEM01, TEM02, TEM10, TEM20 and TEM30; a split type high-order laser beam spot comprises several high-energy areas and low-energy areas which are distributed in a staggered mode, a temperature gradient is formed during welding, metal flows from the high-energy areas to the low-energy areas in a high-speed staggered mode, a welding pool is stirred, and harmful elements are evenly distributed; and a welding wire contains N and Ni, and protective gas is argon, nitrogen and helium. According to the method, the split type high-order laser beam with special energy distribution is combined with the welding wire and a welding process, so that the distribution uniformity of aluminum elements in a welding seam is improved, and the welding quality is improved.

Description

technical field [0001] The invention relates to a tailor welding method of steel plates, in particular to a tailor welding method of aluminum-silicon coated steel plates for vehicles based on split high-order laser beams. Background technique [0002] Aluminum-silicon-coated hot-formed steel is a commonly used steel plate for vehicles, and the welding method of aluminum-silicon-coated hot-formed steel in the prior art is mostly laser welding. Due to the high quality requirements for the welding of plates in the automotive field, when welding aluminum-silicon coated steel plates with laser wire filler, the pre-weld assembly gap, plate thickness, coating thickness, welding process parameters, wire diameter and coating of the plates to be welded, etc. All have strict requirements. However, the actual welding process often cannot meet the welding design requirements. Harmful elements such as aluminum are easily melted into the welding pool, and the weld metal is rapidly solidif...

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Problems solved by technology

[0004]1. Remove all or part of the aluminum-silicon coating in the welding area before performing laser welding, but since the coating, plate and welding wire may contain aluminum, sulfur, phosphorus, etc. Harmful elements, the flow of harmful elements such as aluminum, sulfur, phosphorus cannot be effectively controlled during welding, resulting in the concentration of harmful elements cannot be effectively suppressed

[0005]2. The aluminum-silicon coating is not removed, and the welding wire of special material is used for laser welding. The welding wire of this special material is expensive to develop, and its versatility is poor, so it cannot be widely used For various types of plates, it cannot adapt to the welding of coatings with different components, resulting in poor suppression of the concentration of harmful elements

[0006]At the same time, due to the use of a circular spot laser to provide welding energy in the prior art, the energy in the middle of the spot is concentrated, and the energy at the edge is relatively small, which will further aggravate the harmful elements Concentration, and will lead to uneven strength of the weld

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