Method for avoiding belt breakage of cold-rolled hot forming steel welding line rolling mill

Abstract

The invention discloses a method for avoiding belt breakage of a cold-rolled hot forming steel welding line rolling mill. The method specifically comprises the following procedures that firstly, to improve extensibility of a welding line, front and back heat parameters and welding speed of a laser welding machine are optimized; secondly, low-temperature tempering treatment is conducted on the welding line, and grains of a welding line heat-affected zone of the laser welding machine are refined; and thirdly, a pressure detection instrument is additionally arranged in a cup drawing test machinehydraulic jacking breakage system for detecting a welding line sample plate and is used for detecting the pressure during welding line jacking breakage, the welding line extension performance is judged according to the pressure during welding line jacking breakage, and the quality of the welding line is judged. By means of the method, the hot forming steel welding line ductility is improved by 10%, the rolling mill belt breakage rate of the cold-rolled hot forming steel welding line is reduced to 1.5% from 100%, and the cold-rolled hot forming steel ton-steel hourly output is increased.

Description

technical field [0001] The invention relates to the field of welding of cold-rolled and hot-formed steel, in particular to a method for avoiding strip breakage in a welding mill of cold-rolled and hot-formed steel. Background technique [0002] With the successful research and development of 2000MPa hot-formed steel, the welding process of the acid rolling unit in the cold rolling process has caused great difficulties. The "cupping test" of the weld seam passed the test, but 100% of the weld seam was broken in the rolling process, resulting in a low hourly operating rate of hot-formed steel in the production process of cold rolling steel rolling process, and mass production cannot be concentrated. Since hot-formed steel contains more carbon and manganese than ordinary steel, the ductility of the strip steel in the heat-affected zone before and after the weld is poor in the cold-rolled laser welding process, and the weld cannot meet the deformation requirements during rolling...

AI Technical Summary

Problems solved by technology

[0002] With the successful research and development of 2000MPa hot-formed steel, the welding process of the acid rolling unit in the cold rolling process has caused great difficulties. The "cupping test" of the weld seam is qualified, but 100% of the weld seam is broken in the rolling process, resulting in a low hourly operating rate of hot-formed steel in the production process of cold rolling and steel rolling, and mass production cannot be concentrated

Since hot-formed steel contains more carbon and manganese than ordinary steel, the ductility of the strip steel in the heat-affected zone before and after the weld is poor in the cold-rolled laser welding process, and the weld cannot meet the deformation requirements during rolling, resulting in Weld seam broken strip in rolling mill

[0003] Although the laser welding machine has the advantage of being suitable for welding a wide range of steel types, it is still very difficult to judge the weld quality of steel types with Mn≥1.2% and C≥1.0%. Usually, the weld cup convex test shows that the weld quality is good, but in There is still a 70% risk of strip breakage in welds during rolling, especially for cold-rolled hot-formed steel

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