Abstract: The chemical composition of C97D2-E wire rod for MT grade steel cord was designed by increasing carbon content and Cr alloying to improve the strength of cord steel. A new solidification heat transfer model was established by using Scheil-Gulliver solidification micro-segregation theory to guide C97D2-E continuous casting process， and the defects of central segregation， porosity and internal crack of continuous casting slab were solved. After optimization， the carbon segregation index of semi-finished product can be controlled within 1.05. The air-cooling process was optimized by using specially designed tuyere nozzle and“optiflex” device of Stelmor ， after air-cooling process optimization， the spacing between the layers of wire rod sorbite was obviously reduced， and the sorbite plate was more straight， the lamellar space of the rod was controlled at 89 nm， the particle size of the pearlite was more uniform and smaller， and the size of the pearlite was controlled at 20 μm； the tensile strength of finished steel wire reached 4 089 MPa， there was no delamination during torsion and no broken wire during laying to 5 000 m， which can meet the requirements of 2×0.30 MT steel cord.

Key words: Wire Rod for MT Grade Steel Cord, Soft Reduction, Segregation, Pearlite Nodule, Soxtenite Lamellar Spacing

摘要： 通过增加碳含量及Cr合金化的方式提高帘线钢的强度，设计了MT级钢帘线用盘条C97D2-E的化学成分；采用Scheil-Gulliver凝固微观偏析理论建立新凝固传热模型，指导C97D2-E的连铸工艺，解决了连铸坯中心偏析、疏松和内裂等缺陷，优化后半成品的碳偏析指数可控制在1.05以内；采用特殊设计的风口喷嘴配合斯太尔摩风机的“佳灵”装置，进行风冷工艺优化，优化后盘条索氏体片层间距明显减小，索氏体片更加平直，索氏体片层间距控制在89 nm，珠光体团晶粒度更加均匀细小，珠光体团大小控制在20 μm；成品钢丝抗拉强度达到4 089 MPa，扭转过程中无分层，捻制5 000 m无断丝，可满足2×0.30MT规格钢帘线的要求。

关键词: MT级钢帘线用盘条, 轻压下, 偏析, 珠光体团, 索氏体片层间距