A cooling method for continuous casting slab

Abstract

The invention discloses a high-quality continuous casting billet cooling device and method. The high-quality continuous casting billet cooling device comprises two fireproof walls (1) which are arranged at a stack position oppositely; the bottom of any of the fireproof walls (1) is provided with a plurality of guide wheels (2); the guide wheels (2) are placed on a guide rail (3) to enable the fireproof walls (1) to slide along the guide rail (3). According to the high-quality continuous casting billet cooling device and method, the slow cooling of continuous casting billets in the high temperature mode can be ensured, the segregation of solute elements of the continuous casting billets is effectively reduced, the uniform degree of the microstructure is improved, the macrostructure of the continuous casting billets is controlled, and the content of the gas in the steel can be reduced.

Description

technical field [0001] The invention belongs to the field of iron and steel metallurgical continuous casting, and in particular relates to a cooling device and a cooling method for high-quality continuous casting slabs. Background technique [0002] With the development of the domestic iron and steel industry, the performance of iron and steel materials continues to improve, and the application range of alloying and microalloying in steel is becoming wider and wider. Due to the current situation of metallurgical continuous casting technology in the domestic iron and steel industry, complete vacuum pure casting is basically impossible to achieve. Based on the basic solidification principle, the continuous casting slab will cause structural segregation and uneven structure during the solidification process, and even High gas content in steel or various surface and internal defects. Lead to local differences and even performance fluctuations in the final product. [0003] The...

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Problems solved by technology

In addition, the segregation of harmful elements is also one of the problems that cannot be ignored. For most steel products, harmful impurity elements such as S and P will damage the performance of the steel. Because of the influence of temperature and solubility, harmful elements will be in the continuous casting slab The formation of enriched zones or even enriched layers, and these layers and zones have no effective means and measures to destroy them during the solidification process, will have an impact on the final properties of the steel

[0005] Inhomogeneous structure: Based on the solidification theory, in the continuous casting process, when the molten steel contacts the copper plate of the mold, a dense chilled layer with fine grain size is first formed, and then a dendrite zone is formed. In this zone, a more serious Interdendritic segregation, and finally a thick equiaxed crystal region is formed in the center of the continuous casting slab. At this time, the solute elements and impurity elements are segregated in the arc or straight arc continuous casting slab to form the entire as-cast structure. In the continuous casting machine, the mold electromagnetic stirring technology, soft reduction and solidification end electromagnetic stirring technology can improve the uniformity of the slab structure, but it requires a huge investment

And for a long time, metallurgists hope to improve the uniformity and compactness of the as-cast structure of the continuous casting slab by various means, but the cost is expensive

[0006] The gas content in the steel is relatively high. During the production in seasons with high air humidity, the raw materials used in the production process will contain relatively high moisture. The moisture brought into the billet due to the humidity of the raw materials or the inhalation of the raw materials will be in the steel. The formation of H atoms in the steel will be extremely harmful to the performance of the steel, and will even cause a large amount of waste products. In addition, when the free nitrogen in the steel is not controlled, it is easy to produce a series of defect

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