Low-carbon boron-containing steel continuous casting slab corner crack control method

Abstract

The invention relates to a low-carbon boron-containing steel continuous casting slab corner crack control method. The method includes the steps that firstly, component control is conducted; secondly,the hot metal ratio in the converter smelting process is controlled to range from 85.0% to 87.0%, a bottom blowing mode is adopted in the whole process, nitrogen is blown firstly and argon is blown secondary in the blowing process, blowing is achieved through one shot, and the use proportion of nitrogen and argon is 1:9; thirdly, the C content of the smelting end point is controlled to range from0.035+ / -0.02, and the tapping temperature ranges from 1660+ / -5 DEG C; fourthly, a half-deoxygenation technology is adopted for tapping in the converter smelting tapping process; fifthly, deoxidizing and alloying are conducted at the same time in the tapping process; sixthly, after tapping is conducted, a steel ladle is directly converted into an argon station for argon blowing refining; and seventhly, in the continuous casting process, strong cooling control is conducted on a wide and narrow foot roll area of the continuous casting billet, a second area, a third area and a fourth area of a vertical bending area and a first section of an arc section, and then conventional cooling control is adopted on the second section, the third section, the fourth section, the fifth section, the sixth section, the seventh section and the eighth section of the arc shape. By means of the low-carbon boron-containing steel continuous casting slab corner crack control method, the casting billet corner crack generation rate of the low-carbon boron containing steel is stably controlled to be smaller than 0.1%.

Description

Technical field: [0001] The invention relates to a method for controlling cracks at corners of low-carbon boron-containing steel continuous casting slabs, and belongs to the technical field of continuous casting of iron and steel. Background technique: [0002] Boron-containing steel is an important part of microalloyed steel. Adding boron to steel can significantly improve the hardenability of steel, and can improve the high-temperature strength and creep strength of heat-resistant steel, improve the red hardness of high-speed steel and the cutting ability of tools, and is widely used in modern steel production. However, in the actual continuous casting production process of boron-containing steel, transverse crack defects frequently occur at the corners of the slab, resulting in serious cracks and warped skin quality defects at the edge of the rolled product. For this reason, most of the continuous casting slabs produced need to be off-line for corner flame cleaning, whic...

AI Technical Summary

Problems solved by technology

At present, there is no process or method to effectively control the cracks at the corners of the continuous casting slab in the continuous casting process of iron and steel enterprises to produce low-carbon boron-containing steel.