【摘要】 采用先进的测试技术,并结合现场生产试验,查清了连铸坯产生夹渣的主要原因是浸入式水口穿裂、插入深度浅、结晶器电磁搅拌强度过大,造成结晶器卷渣。其次是钢包下渣卷入钢水中,钢中氢含量高与大颗粒夹杂形成渣气孔,钙处理加入Si-Ca量大,钙侵蚀耐火材料形成mCaO.nAl2O3未上浮留在钢中。为此,采用提高耐火材料质量及合理烘烤制度,降低结晶器搅拌电流,增加浸入式水口插入深度≥120 mm,提高钢的纯净度,降低氢含量,钙处理加入Si-Ca量控制在0.25~0.35 kg/t,使合金结构钢连铸坯低倍夹渣完全消除,确保了合金结构钢铸坯的内部质量。更多还原

【Abstract】 The main reasons of slag entrapment in structural alloy steel obtained with advanced measuring technique and on the spot are un-favorite flow field in mould caused by submerged nozzle cracking,short submerged depth of submerged nozzle,over stirring of M-EMS（Mould Electromagnetic Stirring）,then the others are slag carry over from ladle,high content of hydrogen in the molten steel,mCaO·nAl₂O₃ are formed due to corrosion of stopper head and nozzle by Ca from Ca-Si for modification.So the stirring power of the M-EMS was reduced,submerged depth of the submerged nozzle was increased（≥120 mm）,the amount of hydrogen in the molten steel was reduced,the amount of Si-Ca for Ca treatment is controlled in a range of 0.25⁰.35 kg/t.And finally,the high quality structural alloy steel billets can be produced with high yield.更多还原