Smelting control method of bake hardening steel

Abstract

The invention discloses a smelting control method of bake hardening steel. The method includes the steps that converter tapping is conducted, and post-converter carbon content is obtained; the temperature and arrival oxygen content of steel are measured, and whether the oxygen blowing operation needs to be conducted or not is determined according to the post-converter carbon content and the arrival oxygen content; if yes, vacuum decarburization processing is conducted on the steel, and the oxygen blowing operation is conducted at the same time; an aluminum block is added to conduct the deoxygenation operation, and circulation is conducted for 2 min to 3 min; micro-carbon ferromanganese and ferroniobium are added to conduct the alloying operation, and circulation is conducted for 2 min to 3 min; the carbon content and the niobium content of the steel are obtained; the amount of medium-carbon ferromanganese needing to be added is calculated according to the carbon content, the niobium content and the BH value of the bake hardening steel; and circulation is conducted for 8 or more minutes. The decarburization speed and the controllability of oxygen activity obtained after decarburization is finished are increased by supplying oxygen in vacuum decarburization processing, the alloy addition sequence is adjusted, the carbon adjustment amount is calculated according to the carbon content and the niobium content and through the combination with the requirement for the BH value, the influence of fluctuation of the niobium absorption rate on BH value control is avoided, the processing time is shortened, aluminum only needs to be added once, and influences on the quality of molten steel are reduced.

Description

technical field [0001] The invention relates to the technical field of refining technology in the metallurgical industry, in particular to a method for controlling the smelting of bake-hardened steel. Background technique [0002] The current method of smelting bake-hardened steel is non-killed tapping of converter, natural decarburization of refined RH, and long decarburization time. After the decarburization is completed, samples are taken to analyze the carbon content, and ferro-niobium and medium-carbon ferromanganese are added according to the requirements of carbon content and BH value. Due to the fluctuation of niobium absorption rate and the fluctuation of carbon content in medium-carbon ferromanganese, the actual value deviates greatly from the theoretical value, and the qualified rate of BH value is low, which affects the refining rate of bake-hardened steel, and the process takes a long time and the aluminum loss is large , Secondary aluminum adjustment in the la...

AI Technical Summary

Problems solved by technology

[0003] This application provides a method for controlling the smelting of bake-hardened steel, which solves the problem of large deviation between the actual value and the theoretical value and the low qualified rate of BH value due to fluctuations in niobium absorption rate and medium-carbon ferromanganese carbon content in the prior art. Affect the smelting rate of bake hardened steel, and the process takes a long time, the aluminum loss is relatively large, and the secondary aluminum adjustment in the later stage affects the quality of molten steel.

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