Induction furnace dephosphorization method adopting top and bottom blowing

Abstract

The invention discloses an induction furnace dephosphorization method adopting top and bottom blowing. The method comprises the steps of filling materials, melting, smelting through top oxygen blowing, stopping top oxygen blowing when time of the oxygen blowing reaches 34%-36% of the oxygen-feeding time of the whole journey, discharging slag, continuing the top oxygen blowing, blowing argon or oxygen from the bottom of the furnace when the time of the oxygen blowing reaches 75% of the oxygen-feeding time of the whole journey, stopping the top blowing when smelting reaches a range of steel liquid carbon target range, increasing intensity of bottom blowing, discharging the slag and deoxidizing normally, and tapping steel and finishing billets. The method can solve the problem of dephosphorization or peroxidation caused by carbon- phosphorus reaction competitive oxidation. By means of low-temperature slag discharge, dephosphorization loading is reduced. By means of inert gas top and bottom blowing, the peroxidation in a smelting pool is restrained so that steel liquid phosphorus content at the end point reduces to 0.0050-0.0080wt.%, dissolved oxygen content is less than 0.060wt.%, and nitrogen content is less than 0.0020wt.%. Steel cleanliness is greatly improved. Non-fluorite slagging is adopted during a smelting process, so pollution of fluorine-containing slag to the environment is eliminated.

Description

technical field [0001] The invention relates to the control of impurities in metal smelting, in particular to an induction furnace dephosphorization method using top-bottom blowing. Background technique [0002] Oxide inclusions and phosphorus content in steel are very harmful to the quality and performance of steel. To overcome these defects, it is first necessary to reduce the oxygen content and phosphorus content in steel to the level required by users through steelmaking methods, and to suppress the molten pool synchronized with dephosphorization. peroxidation, reduce production cost. [0003] However, there is a competitive oxidation of carbon-phosphorus reaction in the steelmaking process, which makes the high-carbon area in the low-oxygen position unsuitable for deep dephosphorization; the target temperature of blowing low-carbon steel is not good for dephosphorization, and there is also molten pool overoxidation in the dephosphorization process , the high oxygen lev...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this scheme is that it is difficult to dephosphorize high carbon in the early stage of smelting, the load of slag is large, and the slag is easy to rephosphorize and overoxidize in the later stage, which affects the cleanliness and yield of steel. Simply increasing the flow rate of bottom blowing gas also shortens the bottom blowing Component life issues