Special mold powder for all-headless high-efficiency continuous casting ESP low-carbon steel and preparation method thereof

Abstract

The invention discloses special mold powder for all-headless high-efficiency continuous casting ESP low-carbon steel and a preparation method thereof. The preparation method of the mold powder comprises the steps of preparation of raw materials, homogenization of the raw materials, electronic proportioning, mixing of dry materials, levigation slurrying, spray granulation, sorting and detection ofparticle sizes of finished products, online analysis and detection of X fluorescence spectra, packaging and warehousing of qualified products and the like. The raw materials of the mold powder comprise, by weight part, 30-35 parts of electro-fused calcium silicate, 10-15 parts of 97 fluorite powder, 3-5 parts of sodium fluoride, 10-15 parts of sodium carbonate, 20-25 parts of pre-fusing additives,5-8 parts of cryolite, 2-4 parts of N oil carbon black, 1-2 parts of natural gas carbon black, 3-5 parts of battery grade lithium carbonate and 2-5 parts of carboxymethyl cellulose sodium. The binarybasicity of the mold powder is 1.13-1.23, and the viscosity at 1300 DEG C is 0.08-0.22 Pa.s; and the fusing point is 965 DEG C-1025 DEG C. The special mold powder for the all-headless high-efficiencycontinuous casting ESP low-carbon steel has the excellent characteristics of stable powder consumption, stable heat flow, reduction of the bonding alarm number, novel formula, high rate of continuouscasting finished products, significant reduction of cost compared with the cost of imported powder, etc.

Description

technical field [0001] The invention belongs to the technical field of continuous casting, and in particular relates to a special mold slag for full headless high-efficiency continuous casting ESP low-carbon steel. Background technique [0002] At present, there are 9 headless high-efficiency continuous casting ESP production lines that have been built or are under construction around the world, with a production capacity of more than 11 million tons. Among them, 5 have been built, 4 of which are in Shandong Rizhao Iron and Steel Company, and one in Arvedi, Italy, has been built abroad. 4 lines are under construction, including Rizhao Steel, Shougang Jingtang, Fujian Dingsheng, and Tangshan Quanfeng. Rizhao Iron and Steel's full-endless high-efficiency continuous casting ESP production line is the first unit of the new generation thin slab continuous casting and rolling production line in the world. It has the following characteristics: [0003] 1. The shape of the convent...

AI Technical Summary

Problems solved by technology

The characteristics of its mold flux are: the basicity is between 0.85 and 1.00; the melting point is between 1080 and 1120°C; the viscosity is between 0.10 and 0.15Pa.s (1300°C); the crystallization temperature is between 1120 and 1160°C. On the whole, its performance is relatively good, but in the process of use, it is found that there are still many problems: 1. Although the alkalinity is low, due to the slightly high melting point and crystallization temperature, it is easy to crystallize, which makes the liquid level fluctuate greatly 1. The bonding alarm is abnormal, and the labor intensity of the on-site staff is relatively high; 2. The flame is unstable, the liquid surface is not active, and it is easy to freeze steel; 3. The cost of imported slag is 18,000 yuan / ton, which is too high

Its melting point is 1180-1240°C, and its viscosity is 0.4-0.6Pa.s. In the face of the full headless high-efficiency continuous casting ESP process, the high melting point and high viscosity will cause the mold slag to easily agglomerate in the mold, and the fluidity is relatively low. Poor, so that there is no slag liquid film between the billet shell and the mold wall, and it is easy to cause direct friction between the billet and the mold wall to cause equipment damage, or cause bonding breakout, resulting in production accidents