Converter chromium-preparation method for low-carbon Cr-containing alloy steel

Abstract

The invention discloses a converter chromium-preparation method for low-carbon Cr-containing alloy steel, belonging to the converter steelmaking field. According to the converter chromium-preparation method, oxygen blowing is stopped after decarbonization and heating in a later smelting period of a converter, ferrochromium alloy is added, the steel is discharged after the terminal temperature and the carbon content reach the standards, aluminum is added into a steel ladle in a steel discharging process so as to carry out deoxygenation, and the Cr content of molten steel reaches 5.0%-5.3%. The converter chromium-preparation method for low-carbon Cr-containing alloy steel has the beneficial effects that the alloy is mainly high-carbon ferrochrome and is reasonably matched with micro-carbon ferrochrome, the alloy cost is low, the yield of the Cr element is high, a terminal molten steel carbon content meets the processing capacity of subsequent vacuum refining, meanwhile, the step of adding silicon iron or aluminum powder to reduce the Cr element in the residue is omitted, the production cost is low, and the economic benefit is good.

Description

technical field [0001] The invention belongs to the field of steelmaking technology, and in particular relates to a method for mixing chromium in a converter for low-carbon Cr-containing alloy steel. Background technique [0002] When the converter process is used to produce chromium-containing steel, the general method of adding ferrochrome alloy is to add it to the ladle, or add it when tapping or add it during the LF refining process, mainly adding micro-carbon ferrochrome, and the cost of the alloy is relatively high. Moreover, when ferrochromium alloy is added in the LF refining process, due to the low temperature of the molten steel and the slow heating rate, in order to avoid the temperature of the molten steel being too low, the alloy often needs to be added in 3 to 4 batches, the smelting cycle is long, and it is difficult to match with the preceding and following processes larger. If ferrochrome alloy is added during the oxygen blowing smelting process of the conv...

AI Technical Summary

Problems solved by technology

The ferrochrome alloy in this process is all micro-carbon ferrochrome, the cost of the alloy is high, and the duration of alloy addition is long. The LF refining time is more than 85 minutes. The long refining period does not match the production rhythm of converter and continuous casting.

[0004] Therefore, in view of the large amount of ferrochrome added in the smelting of low-carbon Cr-containing steel, which leads to high alloy cost and large temperature drop of molten steel, it is necessary to provide a ferrochrome alloy addition method that can reasonably control the process temperature