How to control the quality of converter steelmaking

I am a converter and have worked for several years. Let me talk about my own views. The quality control of converter should pay attention to the following aspects:

The main purpose of converter is to provide molten steel with qualified composition and temperature at the lowest smelting cost. So we should pay attention to the following aspects:

Quality:

1) Scrap steel: Pay attention to the classified management of scrap steel, and avoid using scrap steel with unknown sources when smelting special steel grades;

2) Hot metal: the content of harmful elements remaining in hot metal.

3) Alloy fittings: Pay attention to the content of harmful elements. Ultra-low carbon steel needs to pay attention to alloy carbon content

4) Try to avoid secondary blowing and end point peroxide during smelting, which is harmful to cost and quality.

5) Slag blocking during tapping will not only lead to phosphorus recovery, but also bring great difficulties to slag reduction in refining, which will eventually affect the quality of molten steel;

6) Gas content control: N-N-Ar conversion time of top-bottom combined blowing converter is very important, and nitrogen will be absorbed if tapping time is too long. In addition, if the carburizing agent is petroleum coke, the effect of increasing nitrogen and hydrogen is obvious; H—— Raw and auxiliary materials are dried, and alloy is baked, which can reduce the hydrogen content under the condition that the equipment does not leak molten steel.