A method for controlling inclusions in ultra-low aluminum non-oriented silicon steel

Abstract

The invention provides a method for controlling inclusions in ultra-low aluminum non-oriented silicon steel. The chemical composition mass percentage of the steel is C≤0.005%, Si: 0.25%‑1.50%, Mn: 0.15%‑0.55%, P: 0.02%‑0.06%, S≤0.005%, Als≤0.005%, and the balance is Fe and unavoidable impurities. The process flow is: KR→BOF→RH→continuous casting. Converter tapping strictly controls the amount of slag, adding lime and slag surface deoxidizer to adjust slag at the end of tapping; after RH decarburization, first add low-carbon and low-sulfur ferrosilicon, metal aluminum or aluminum-calcium-iron alloy compound deoxidation, and finally add metal manganese , ferrophosphorus for alloying, and then a net cycle of 6-10min, the steel is broken out and transported to continuous casting. The obtained molten steel is mainly SiO 2 ‑Al 2 o 3 System inclusions, avoiding the formation of low melting point SiO 2 ‑MnO-based inclusions make the rolling elongation longer and affect the grain growth; at the same time, it also avoids the formation of high SiO 2 The components are acidic inclusions, leading to corrosion of refractory materials. It can significantly improve the type of non-metallic inclusions in steel, improve the performance of non-oriented silicon steel, and improve the pouring performance of molten steel.

Description

technical field

[0001] The invention belongs to the technical field of iron and steel smelting, and in particular relates to a method for controlling inclusions in ultra-low aluminum non-oriented silicon steel. Background technique

[0002] Ultra-low aluminum non-oriented silicon steel belongs to cold-rolled non-oriented silicon-manganese static electricity steel, such as W1300 and so on. Because of its simple manufacturing process, low manufacturing cost, wide range of uses, and large market demand, it is widely used in the production of household motors and micro motors, small motors, ballasts and transformers, etc. It is a national power, electronics and military industry. Indispensable soft magnetic alloy.

[0003] At present, the smelting process of non-oriented silicon steel is relatively mature, and its conventional production process is: KR desulfurization→converter smelting→RH vacuum refining→continuous casting. Ultra-low aluminum non-oriented silicon steel is sil...

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