Process for low-carbon silicon-controlled aluminum killed clean steel

Abstract

The invention discloses a process for low-carbon silicon-controlled aluminum killed clean steel and belongs to the field of steel preparation. The production process comprises the following steps: (1)reducing the sulfur content of molten iron to 0.02% or below by means of molten iron pretreatment and the like; (2) an oxygen top-bottom combined blown converter is adopted, specifically, slag stop and tapping are carried out, and the end-point molten steel [O] of the converter is less than 600 ppm; (3) LF refining is carried out, specifically, the slag is controlled to comprise 55-60% of CaO, 35-40% of Al2O3, 2-4% of SiO2 and 5-7% of MgO, specifically, the alkalinity value of CaO / SiO2 is 20-26, refining is carried out to make white slag, the aluminum component of the molten steel is adjusted, and aluminum is dosed twice; (4) soft blowing and calming argon at the bottom of a steel ladle; (5) continuous casting is carried out; and (6) rolling steel. Compared with the prior art, the methodhas the advantages that the calcium treatment cost is saved, the problems that high-melting point aluminate is prone to flocculation and nitrogen increase are avoided, the forming performance of a steel plate is improved, and the occurrence probability of cold bending cracking is reduced.

Description

technical field

[0001] The present invention is a divisional application of the invention patent application "A Thin Slab Continuous Casting Low-Cost High Formability Low-Carbon Aluminum Killed Clean Steel Process" (Application No.: 2018100961312). It specifically relates to the field of iron and steel metallurgy technology, especially a production technology for producing low-carbon aluminum-killed clean steel with high formability at low cost. Background technique

[0002] Currently producing low-carbon (silicon-containing or silicon-controlled) aluminum-killed steel, the production process generally adopts molten iron→oxygen top-bottom combined blowing converter→LF refining→soft blowing of argon gas at the bottom of the ladle→calcium treatment→soft blowing of argon gas at the bottom of the ladle→thin plate Billet continuous casting→continuous rolling process. Among them, the calcium treatment process is specifically: feeding molten steel into metallic calcium solid cored...

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