Molten steel deoxygenating agent and its prepn

Abstract

The molten steel deoxygenating agent is Fe-base alloy containing Al, Mg and RE, and comprises Mg 8-12 wt%, RE alloy 0.03-1 wt%, Al 48-58 wt% and Fe for the rest, with metal Mg being added while the Al-containing molten steel at the temperature of 900-1100 deg.c. The molten steel deoxygenating agent has great density, Al and Mg yield, high S and O eliminating capacity, and other advantages.

Description

technical field [0001] The invention belongs to the field of ferroalloy production, and more specifically relates to an improved technology for steelmaking deoxidizer production. Background technique [0002] Deoxidized alloys are the most important materials in the steelmaking process. In principle, any metal that can react with oxygen in steel can be selected as a deoxidizer material. Usually, there are several basic requirements for the deoxidizer: first, it can remove dissolved oxygen in molten steel; second, the substances generated by the reaction are relatively easy to float up from the molten steel and discharged out of the molten steel; third, the deoxidation is complete and the cost of deoxidation is reasonable. [0003] Theoretical research and practice have proved that metal aluminum is currently the most widely used material with the most thorough deoxidation and the best deoxidation effect. Aluminum In addition to deoxidation, the metal aluminum in steel is a...

AI Technical Summary

Problems solved by technology

[0006] The specific gravity of aluminum is 2.7g / cm 3 , less than slag 3.0 ~ 3.5g / cm 3 And molten steel 7.0g / cm 3 , it is difficult to pass through the slag layer during the addition process, and part of it remains in the slag; the aluminum alloy entering the molten steel, due to the shallow penetration depth, is easy to float into the slag during the melting process. Two reasons lead to a low yield of metal aluminum. According to the production In practice, the deoxidation yield of metal aluminum is less than 10%.

[0007] Although the simple mixed alloy of aluminum and iron can enter the molten steel through the slag layer, after entering the molten steel, due to the low melting point of aluminum, it will be separated from the iron immediately, and the aluminum will float rapidly during the melting process, and the yield is also low. Generally, Not more than 12%

In addition, due to the use of aluminum-clad iron, the production process of the product is easy to falsify, and it is also difficult to inspect and accept after entering the steel factory

[0008] The common problem of aluminum and aluminum alloys is that after deoxidation of aluminum, fine aluminum oxide inclusions are formed, which are dispersed in steel. Since the melting point of aluminum oxide is higher than that of steel, it is difficult to The aluminum oxide left in the steel has two hazards: one is that during the pouring process of molten steel, as the temperature decreases, the fine aluminum oxide inclusions will re-precipitate and adhere to the On the wall of the refractory material nozzle, the number of nozzles is increasing continuously, and the nozzle is blocked, which affects the smooth progress of continuous casting

Second, aluminum oxide inclusions affect the purity of the steel, and ultimately affect the performance of the steel

However, due to the low melting point of magnesium metal (648°C), the vapor pressure is as high as 2.038×10 at the steelmaking temperature. 6 Pa, the safety issue of adding magnesium metal to molten steel and the utilization rate of molten steel treated with magnesium metal have always been the main problems restricting the deoxidation of metal magnesium