A Method of Improving the Toughness of Thick Plate Core by Utilizing Descaler Box

Abstract

The invention discloses a method for improving the toughness of a thick plate core by using a descaling box. The method includes the following steps: (1) After the slab is released from a heating furnace, the first pass of rough rolling is moved to the descaling box before the start of the first pass. The internal high-strength cooling, and the first pass of rough rolling is carried out within 15s after cooling; (2) the third pass of rough rolling of the cast slab is moved to the descaling box for high-strength cooling, and the rough rolling is carried out within 10s after cooling. The third pass is rolled. In the present invention, without increasing the added amount of alloying elements and without changing the conditions of the existing process equipment, the steel plate can be cooled with high strength by using descaling box equipment before entering the first pass and the third pass of rough rolling, so as to realize the steel plate. The temperature gradient in the thickness direction, and then after rolling with a large reduction, the rolling force can be transmitted through the "hardened" steel plate surface to the "softened" steel plate core, effectively breaking the grains and refining the core grains , so that the density of the heart tissue is improved, and the toughness of the heart is improved.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for improving the toughness of a thick plate core by using a descaling box. Background technique [0002] At present, with the development of the domestic construction industry, thick gauge plates are gradually being used in harsher service conditions. However, for the thick plate itself, due to the relatively serious segregation of elements in the central area and the relatively loose structure density, the toughness of the thick gauge plate is mostly at a low level under the production conditions of conventional process equipment, which cannot meet the requirements of the production process. Service performance under harsh conditions, so it is necessary to adopt technical methods to effectively improve the toughness of the heart. [0003] It is generally believed that the impact performance of the core is directly related to the toughness of the core. I...

AI Technical Summary

Problems solved by technology

However, for the thick plate itself, due to the relatively serious segregation of elements in the central area and the relatively loose structure density, the toughness of the thick gauge plate is mostly at a low level under the production conditions of conventional process equipment, which cannot meet the requirements of the production process. Service performance under harsh conditions, so it is necessary to adopt technical methods to effectively improve the toughness of the heart

[0003] It is generally believed that the impact performance of the core is directly related to the toughness of the core. Increasing the compression ratio can improve the impact performance of the core of the steel plate. However, for existing iron and steel enterprises, the process and equipment conditions have been determined. The thickness of the cast slab can no longer be increased. If you want to improve the toughness of the steel plate core by increasing the compression ratio, you can only achieve it through equipment transformation, but it requires a large investment to achieve it.

In addition, increasing the addition of alloying elements is an effective means to improve toughness, but this will significantly increase production costs and is not suitable for mass production; the method of using a large reduction in the rolling mill in the finishing rolling stage is also conducive to improving the core impact. performance, but the capacity range of the rolling mill itself must be considered. At the same time, the large reduction of the steel plate under low temperature conditions in the finishing rolling stage will also cause damage to the roll itself, which will increase the cost, and may even cause rolling mill accidents and affect the production rhythm.

Images