RH (relative humidity) treatment method for phosphorus-containing interstitial-free atom steel

Abstract

The invention relates to the technical field of continuous casting refining treatment and in particular relates to an RH (relative humidity) treatment method for phosphorus-containing interstitial-free atom steel. The RH treatment method is characterized by firstly adding low-carbon ferrophosphorus before RH molten steel is calmed and comprising the following operating steps of: 1) evacuating for 2-3 minutes in a vacuum chamber, adding low-carbon ferrophosphorus according to phosphorus content of an argon station sample, and controlling phosphorus component in the content 0.003% less than the upper limit of the finished product; 2) alloying according to a process sample, and if content of the phosphorus component is less than the lower limit required by steel, replenishing the low-carbon ferrophosphorus in the content 0.002% more than the lower limit of the phosphorus component; and 3) after alloying is finished, guaranteeing that clean circulating time is not less than 5 minutes; and stopping vacuum treatment, and adding 200-250kg of converter slag on the slag surface in an insertion tube region to modify top slag. Compared with the prior art, the RH treatment method provided by the invention has the beneficial effects that adverse influence caused by the low-carbon ferrophosphorus added after molten steel is calmed can be eliminated, and cold rolling inclusion defect rate is reduced to 0.43% from 1.53%.

Description

Technical field [0001] The invention relates to the technical field of continuous casting refining treatment, in particular to a RH treatment method for phosphorus-containing steel without interstitial atoms. Background technique [0002] RH produces phosphorus-containing non-interstitial atomic steel, adding low-carbon phosphorus iron after the molten steel is killed, if it is cast on a medium and thin slab caster. The castability of molten steel is not good, and it is easy to flocculate. 4-6 tanks in one pouring time need to replace the immersion nozzle several times, which may even cause flocculation to stop pouring. The replacement of the nozzle due to flocculation has a negative impact on the product quality of the next process, and the steel plate inclusion rate is also high. Summary of the invention [0003] The purpose of the present invention is to provide a RH treatment method for phosphorus-containing non-interstitial atom steel, which reduces the flocculation phenomen...

AI Technical Summary

Problems solved by technology

The pourability of molten steel is not good, and it is easy to flocculate. One pouring of 4 to 6 cans needs to replace the immersion nozzle many times, which may even cause flocculation to stop pouring.

The replacement of the nozzle due to flocculation will have a negative impact on the product quality of the next process, and the steel plate inclusion rate is also high