Welding-wire-free welding method for medium and high-grade non-oriented silicon steel

Abstract

The invention discloses a welding-wire-free welding method for medium and high-grade non-oriented silicon steel, and belongs to the technical field of laser welding for non-oriented silicon steel. The welding method comprises the following steps: 1) connecting the strip tail of low-grade non-oriented silicon steel with the strip head of the medium and high-grade non-oriented silicon steel in a centering contact manner; 2) carrying out preheating treatment on a weld joint between a leading strip and base metal before laser welding, then adopting a laser welding machine for welding, and after the welding is completed, carrying out high-temperature tempering treatment on the weld joint; and 3) after the welding is completed, alternately welding the medium and high-grade non-oriented silicon steel and the low-grade non-oriented silicon steel according to the steps. The welding method has the following beneficial effects: the rolling parameters of a continuous rolling unit are properly adjusted through the processes of reasonably selecting the leading strip, preheating before the welding and carrying out the tempering treatment after the welding, so that welding-wire-free welding for the medium and high-grade non-oriented silicon steel is realized, the quality of the weld joint is improved, the strip breakage rate is reduced, continuous rolling for the weld joint is guaranteed, and the rolling efficiency is increased.

Description

technical field [0001] The invention relates to the technical field of laser welding of non-oriented silicon steel, in particular to a method for welding non-oriented silicon steel of medium and high grades without welding wire. Background technique [0002] The acid rolling unit is a fully continuous high-speed production unit. During production, the tail of the previous strip and the head of the current strip are welded by laser welding equipment to ensure the continuous production of the acid rolling unit. The welding place is commonly called welding. seam. The range of steel types welded by the laser welding machine of the acid rolling mill is: hot-rolled low-carbon steel, ultra-low-carbon steel, low-alloy high-strength steel, low-grade non-oriented electrical steel, and for silicon steel products, due to the relative silicon content in the material It is much higher than ordinary carbon steel, and the plasticity and toughness of the material are poor. When laser weldin...

AI Technical Summary

Problems solved by technology

The range of steel types welded by the laser welding machine of the acid rolling mill is: hot-rolled low-carbon steel, ultra-low-carbon steel, low-alloy high-strength steel, low-grade non-oriented electrical steel, and for silicon steel products, due to the relative silicon content in the material It is much higher than ordinary carbon steel, and the plasticity and toughness of the material are poor. When laser welding this material, the weld seam is brittle and produces a large weld seam stress, which makes the mechanical properties of the weld seam compared with the base metal. There is a certain gap, especially the significant decrease in the bending strength, which makes it difficult to meet the fields that have high requirements for the mechanical properties of the weld, so the medium and high grade non-oriented silicon steel is not within the welding range of this welding machine

[0003] For non-oriented silicon steel products with high silicon content, the traditional welding process cannot meet the requirements of its continuous production, and can only be produced in a single coil with a reversing rolling mill, and its production efficiency will be greatly reduced

[0004] Although some manufacturers have realized the continuous production of medium and high-grade non-oriented silicon steel by using welding wire welding, there are disadvantages such as high equipment investment cost and high welding process cost when using welding wire welding