A solidification quality control method for vertical continuous casting slabs of large-scale medium-high alloy steel

Abstract

The invention belongs to the technical field of continuous casting, and in particular relates to a method for controlling the solidification quality of large-scale medium-high alloy steel vertical continuous casting slabs. It significantly improves the internal quality of the produced continuous casting slab. It includes the following steps: Step 1. When casting a large-size round billet, drive the tundish car to the casting position of the continuous casting machine, and the submerged nozzle is opposite to the center of the crystallizer, and lowered to the specified position; Step 2. Open the tundish stopper mechanism to make the middle and high The molten alloy steel is injected into the water-cooled crystallizer through the submerged nozzle; step 3, the secondary cooling system, the electromagnetic stirring system and the nip roller device are automatically started, and the round billet passes through the water-cooled crystallizer, the secondary cooling system, the nip roller device, and the radiation zone electromagnetic After the agitator enters the heat preservation device in the radiation area, it finally passes through the terminal electromagnetic agitator; step 4, stop pouring after the dummy ingot is lowered to the specified position, the round billet is cooled to the required temperature and then flame cut, and the cut round billet is delivered by the output roller Export to the heat preservation pit and slowly cool to room temperature.

Description

technical field [0001] The invention belongs to the technical field of continuous casting, and in particular relates to a method for controlling the solidification quality of large-scale medium-high alloy steel vertical continuous casting slabs. Background technique [0002] Special steel is a key material required for major equipment manufacturing and national key project construction. It is a high-tech product among steel materials. Its production and application represent a country's industrialization development level and are the basic guarantee for national comprehensive competitiveness and national security. . [0003] At present, large-scale alloy steel continuous casting slabs are mostly produced by vertical bending or arc continuous casting machines. Limited by the metallurgical characteristics of continuous casting machines, this type of equipment is mainly used to produce low-alloy steel continuous casting slabs. For continuous casting slabs, it has high producti...

AI Technical Summary

Problems solved by technology

However, for large-scale continuous casting slabs, the cooling intensity in the secondary cooling zone is difficult to penetrate into the inner layer of the slab, which makes it difficult to control the solidification and feeding behavior of the slab, and the central feeding defect is prominent

In addition, the solidification rate of large-scale continuous casting slabs is low, and the solutes that are easy to segregate have sufficient time to diffuse and gather. The larger the section of the slab, the more prominent this problem

Therefore, central feeding defects and solute segregation become bottlenecks restricting the improvement of solidification quality of large-scale continuous casting slabs

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