80t顶底复吹转炉-1~# LF-2~# LF-VD-CC流程帘线钢XLX72A的开发

通过转炉终点控制-%:≥0.12C、≤0.008P、≤0.010S-1~#LF碱性渣精炼≥40 min,2~#LF酸性渣(R=0.8～0.9)精炼30 min-VD 67 Pa≥10 min,软吹氩≥15 min-保护浇铸(钢水过热度≤30℃),结晶器和末端电磁搅拌等工艺措施,开发了帘线钢XLX72A(%:0.69～0.73C、0.20～0.28Si、0.47～0.55Mn、≤0.015P、≤0.015S、≤0.05Ni、≤0.08Cr、≤0.05Cu、≤0.005A1)。结果表明,钢中Cu、Al含量分别为0.02%～0.03%和0.002%～0.003%,Φ5.5 mm材的抗拉强度R_m为1 050～1 090 MPa,断面收缩率Z为43.5%～48.0%,钢中低倍组织和显微夹杂物级别均符合标准要求,使用性能良好。

Development of Tire Cord Steel XLX72A by 80 t Top and Bottom Combined Blown Converter-LF No1-LF No2-VD-CC Flow Sheet

The tire cord steel XLX72A(%:0.69～0.73C,0.20～0.28Si,0.47～0.55Mn,≤0.015P,≤0.015S,≤0.05Ni,≤0.08Cr,≤0.05Cu,≤0.005Al) has been developed by using the operation measures includingconverter end controlling -%:≥0.12C,≤0.008P,≤0.010S- LF Nol basic slag refining for≥40 min- LF No2 acid slag(R = 0.8～0.9) refining for 30 min- 67 Pa VD refining for≥10 min and soft argon blowing for≥15 min- shielding casting(liquid overheating≤30℃) with mold and end electromagnetic stirring.Results show that the Cu and Al content in steelare respectively 0.02%～0.03%and 0.002%～0.003%,the tensile strength R_m ofΦ5.5 mm product is 1 050～1090MPa and its reduction of area Z is 43.5%～48.0%,the ratings of macrostructure and micro inclusions in steel meet therequirement of standard,and its service performance is better.