Method for reducing fracture zones of high-hardenability cold-rolled high-strength steel cold-rolled edges

Abstract

The invention relates to a method for reducing fracture zones of high-hardenability cold-rolled high-strength steel cold-rolled edges. The method comprises the steps of high-strength steel smelting, heating by heating furnace, rough rolling, descaling, 2250 mm hot continuous rolling, laminar cooling and reeling, wherein the laminar cooling adopts a rear section 1 / 2, and meanwhile, the water spraying on the fine adjusting area side is closed. According to the method, the defect of fracture zones of the high-hardenability high-strength steel cold-rolled edges can be effectively solved under thecondition that normal production and product performance are not influenced, and the yield and the instant production of strip steel are improved.

Description

technical field [0001] The invention relates to a method for controlling the fractured strip at the cold-rolled edge of a steel strip, in particular to a method for reducing the fractured strip at the cold-rolled edge of the high-hardenability cold-rolled high-strength steel. Background technique [0002] With the deepening of automobile lightweight, the proportion of high-strength steel in automobile steel continues to rise. In order to obtain high strength, high-strength steel generally adopts high-alloy system or high-carbon system, and these component systems make the steel plate have high hardenability. Generally, as the strength increases, the alloy content increases, and the hardenability also increases. However, high-hardenability high-strength steels are prone to martensitic transformation if the cooling rate is too fast, especially after hot rolling. During the coiling process, the cooling rate at the edge is fast, and it is easy to form brittle structures or stre...

AI Technical Summary

Problems solved by technology

Generally, as the strength increases, the alloy content increases, and the hardenability also increases. However, high-hardenability high-strength steels are prone to martensitic transformation if the cooling rate is too fast, especially after hot rolling. During the coiling process, the cooling rate at the edge is fast, and it is easy to form brittle structures or stress cracks. In severe cases, hot-rolled raw materials may even cause rotten edges, resulting in low plasticity at the edge of the strip, and edge fractures during the cold rolling deformation process. high

The Chinese patent with the patent number 201810882943.X discloses "a method for preventing hot-rolled steel sheets from edge fracture during cold rolling", and "China Metallurgy" published "980 MPa dual-phase steel edge Analysis of the Causes of Strip Fractures Caused by Cracks”, the two public technologies proposed to put in slow cooling pits and close the side spraying measures for finishing rolling for DP980 cold rolling edge cracks. Difficulty, further increasing the difficulty of rolling, resulting in high rolling cracking rate, at the same time, no corresponding solution to the problem of edge cracking of high-hardenability high-strength steel

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