Method for removing residual stress of hot-rolling high-strength steel

Abstract

The invention relates to a method for removing residual stress of hot-rolling high-strength steel, which comprises the production flows of: (1) putting a steel coil of which the thickness is more than or equal to 8 millimeters into a slow cooling pit for slow cooling treatment; and (2) performing air cooling on a steel coil of which the thickness is less than 8 millimeters, and after the steel coil is cooled to reach room temperature, performing temper rolling and performing reeling again to form a coil. A roller-type straightening unit is adopted to perform straightening, flattening, dimensioning and cross-cut on the treated high-strength steel coil to form a steel plate. A roller-hearth heat treatment furnace is adopted to perform stress relief annealing on the flattened steel plate, so that the internal stress of the steel plate is eliminated; and after being tapped off, the steel plate is cooled slowly by adopting a stacking cooling mode, and finally the steel plate is straightened by using the straightening unit, so that the high-strength steel plate has the excellent plate shape stability and can meet the strict requirements of users on flatness of less than or equal to 2 mm / m of the high-strength steel plate. The conventional heat treatment furnace and roller-type straightening equipment can be utilized, so that the investment cost and machining cost are reduced, the annealing treatment time is shortened, and the effect of the plate shape improvement of hood-type annealing is achieved. Thus, the method has an important economic and social significance for the development of the high-strength steel.

Description

technical field [0001] The invention belongs to the technical field of steel processing methods, and relates to a method for eliminating residual stress of hot-rolled high-strength steel plates, which is particularly suitable for eliminating residual stress generated in the rolling and cooling process of hot-rolled high-strength steel, and finally meets the shape quality of high-strength steel users. Require. Background technique [0002] Hot-rolled high-strength steel for construction machinery and automobile beam plates are produced in the form of steel coils, which need to be straightened and cross-cut into steel plates when users use them. Plate shape is a quality indicator that users are increasingly demanding. Serious plate shape defects may cause delays in production, damage to processing equipment, and welding difficulties when users use it. It is necessary to control the shape of the final coil, and the products provided to users have high-quality shape. The trend...

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Problems solved by technology

However, due to the difficulty in controlling the shape of thin-gauge cold-rolled products such as hot-rolled pickled plate, thin-gauge container plate, high-strength steel and tinplate, temper rolling is required, which brings difficulties to the production of temper mills. Huge pressure, it is difficult to complete the leveling task of all steel grades

At the same time, the investment amount of the bell annealing furnace is relatively large, and the investment cost is relatively high. Therefore, it is necessary to improve the residual stress elimination process route for hot-rolled high-strength steel products, especially thick-gauge products.

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