Crystallizer casting powder special for high-strength steel containing vanadium, niobium, titanium of plate blank continuous casting and manufacturing technique thereof

Abstract

The invention relates to a specific mould powder of crystallization mould of high strength steel containing V, Nb, Ti of slab costing and a production process thereof. The mould powder comprises pre-melted raw materials, flux materials, alkalinity adjustment materials and carbonaceous materials, and the weight percentages are that: 78-85 percent of pre-melted raw materials, 5-12 percent of flux materials, 5-10 percent of alkalinity adjustment materials and 2-6 percent carbonaceous materials; the production process of the invention is: various qualified materials are crushed to appropriate size and sent into a furnace; water quenching is carried out to the material taken out from the furnace; then gasification is done and sent into a pre-melted material storehouse. The qualified pre-melted raw materials, flux materials, alkalinity adjustment materials and carbonaceous materials are made to be gasified and sent into the material storehouse to be burdened, then sent into a mixer; a semi-finished product is made to be tested, if qualified, sent into a ball mill to be dry ground and into a water mill to be finely ground, so as to make slurry; the next steps are material extraction, spraying, product testing, packaging and storing. The production of the invention has the advantages that product has little slag strip; the spreading property of the crystallization mould is good; reaction inside the crystallization mould is active with small flame.

Description

Technical field [0001] The invention relates to a slab continuous casting mold powder for high-strength steel containing vanadium (V), niobium (Nb) and titanium (Ti) and its production process. Background technique [0002] At present, most domestic high-grade steel products still rely on imports, among which high-strength steel containing V, Ni, and Ti is one of them. The main reason is that the domestic steelmaking, continuous casting level and the quality of the corresponding supporting materials have not yet reached the corresponding requirements. Among the supporting materials, mold powder is one of the key materials. [0003] The main purpose of introducing V, Nb, and Ti into steel is to refine the grains, increase the strength of the steel, and optimize the performance of the steel. However, the subsequent difficulty is that the difficulty of continuous casting increases, because the brittleness range of the cast slab becomes wider. If the process control is slightly impro...

AI Technical Summary

Problems solved by technology

[0006] 1. Imported slag cannot be effectively combined with the actual situation of the domestic operation site, and its adaptability is poor. When casting this type of steel with imported slag, there are still obvious problems of more crack defects;

[0007] 2. Most of the domestic steel mills do not fully realize the importance of mold slag. When casting this type of steel, they usually use mold slag for steel with the same carbon content, and do not use special slag;

[0008] 3. Although some domestic mold slags are designed according to the characteristics of this type of steel, they mainly adjust the heat transfer characteristics of the mold slag through the difference in the crystallization characteristics. The crystallization characteristics of the mold slag play a certain role in the heat transfer of the slab , but the crystallization is very different from the conditions of the crystallizer, and the heat transfer through the wall of the crystallizer is an unsteady process, so it is difficult to achieve the desired effect in practical applications to solve such problems only by adjusting the difference in crystallization performance

For example, the method of adjusting the crystallization used in the patent with the publication number CN1911560A is theoretically reasonable, but in practice, it is found that the effect caused by the difference in crystallization characteristics is not very obvious.

[0009] 4. Due to the imperfect process used in domestic slag, the performance of the slag fluctuates greatly, so the use process is unstable, and it is easy to cause cracks and defects, etc.