Smelting method for improving recovery rate of vacuum aluminum

Abstract

The invention discloses a smelting method for improving the recovery rate of vacuum aluminum, and belongs to the technical field of ferrous metallurgy. A vacuum VD process is included. The vacuum VD process includes the following steps that the total amount of vacuum slag is controlled to be 5-8 kg per ton of steel, the thickness of slag layers is controlled to be 155-165 mm, the content of SiO2 in the slag is reduced to be 10%-12%, nitrogen is introduced at the speed of 320-350 kg / h to prevent air from entering in the vacuum destruction process, and at the same time, argon flow is adjusted tobe 30.5-32 NL / min to ensure that the slag layers are not blown to be open. According to the smelting method for improving the recovery rate of the vacuum aluminum, the recovery rate of the aluminum is increased from original 20%-45% to 70%-75% in the vacuum process, the recovery rate of an aluminum alloy is obviously improved, and the wide application value is achieved.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a smelting method for improving the recovery rate of vacuum aluminum. Background technique [0002] For the fine-grain killed steel with Al element as the final deoxidation, the aluminum content is clearly stipulated in the technical requirements. For example, chromium-molybdenum steel requires that the Al element in the steel reach 0.018%-0.050%, and it is generally believed that the steel meets the requirements of fine-grained killed steel. However, according to the current statistical results of domestic steel mills, the Al deoxidized fine-grain killed steel that needs vacuum treatment, the aluminum wire fed into the molten steel before VD vacuum treatment, is affected by air, slag content, slag layer thickness and slag composition. And so on, its aluminum alloy recovery rate is only 20%-45%. Even after taking certain measures or methods, it is ...

AI Technical Summary

Problems solved by technology

However, according to the current statistical results of domestic steel mills, the Al deoxidized fine-grain killed steel that needs vacuum treatment, the aluminum wire fed into the molten steel before VD vacuum treatment, is affected by air, slag content, slag layer thickness and slag composition. etc., the aluminum alloy recovery rate is only 20%-45%

Even after taking certain measures or methods, it is only close to 50%, and the recovery rate has not been significantly improved, resulting in the unnecessary consumption of a large amount of Al alloys and the inevitable extension of the smelting cycle

In order to maintain the recovery rate of vacuum aluminum, some steel mills even feed a large amount of aluminum wire after the vacuum is over, which eventually leads to the product being scrapped due to excessive aluminum-based inclusions and unqualified flaw detection, resulting in huge losses.