氧气转炉出钢脱硫-LF精炼生产超低硫钢的工艺

Process for Production of Ultra-Low Sulphur Steel by BOF Tapping Desulphurizing-LF Refining

因210tBOF冶炼终点NVA32(%:0.12～0.18C、1.30～1.60Mn)钢中硫含量由0.005%升高至0.020%,通过BOF出钢过程加入1000kg二元合成渣CaO-CaF2、200kg铝粒,并加入硅锰和硅铝钡合金,可使钢中硫含量降低0.007%～0.008%,脱硫率达30%。在LF精炼时,通过进一步加入合成渣800kg,600～900L/min吹氩,加热后喂600m硅钙线,30～45L/min吹氩10min,终渣碱度R=4.5～5.5,钢中硫含量进一步降低至0.001%～0.002%。

Because the sulphur content in steel NVA32 （0. 12 ～ 0. 18C, 1.30 ～ 1.60Mn） increases to 0. 020% at 210 t BOF melting end point from original 0. 005%, it shall be added 1 000 kg binary synthetic slag CaO-CaF2 and added 200 kg aluminium during BOF tapping and added Si-Mn alloy and Si-Al-Ba alloy to decrease sulphur content in steel by 0. 007% ～ 0. 008% with desulphurization rate up to 30%. During LF refining, sulphur content in steel further decreases to 0. 001% ～ 0. 002% by further added 800 kg synthetic slag, blown argon 600 ～ 900 L/min, after heating fed 600 m siliconcalcium wire then blown argon 30 ～45 L/min for 10 min with end slag basicity R = 4.5 ～5.5.