加硼钢连铸坯中间裂纹缺陷的改善  

Improvement of intermediate crack in continuous casting slab with trace boron

作　　者：苏笃星 马建超[1] 夏翁伟 冯红伟 

机构地区：[1]江苏沙钢集团有限公司江苏省(沙钢)钢铁研究院,江苏张家港215625 [2]宏发炼钢厂,江苏张家港215625

出　　处：《炼钢》2013年第3期19-22,共4页Steelmaking

摘　　要：通过对添加硼前后A36钢连铸坯中间裂纹分布特征及其高温力学性能的调查研究,分析了其中间裂纹的形成原因。结果表明,硼的加入降低了钢的零塑性温度是铸坯产生中间裂纹的内因,而铸坯在连铸过程中受弯曲应变、矫直应变以及辊缝不对中引起的过大应变是裂纹产生和扩展的外因。据此提出了相应的改进措施,有效地减轻了A36-B钢连铸坯中间裂纹。The distribution characteristics of intermediate crack, as well as high tempera- ture mechanical properties of A36 （without boron） and A36-B （with boron） slabs are in- vestigated. The result shows that zero ductility temperature decreases after the addition of boron due to the formation of low melting-point borides, sulfides and phosphide at the final solidified grain boundary region. On the other hand, the higher strain caused by the mismatch of roll gap during the bending and unbending process will results in the formation and propagation of the cracks along the interdendritic region. Corresponding- ly, countermeasures to eliminate intermediate crack are put forward, including reducing the content of impurity elements and enhancing the maintenance of roll gap, and then in- termediate crack in A36-B slabs are decreased.

关 键 词：连铸 中间裂纹 零塑性温度 

分 类 号：TF777.1[冶金工程—钢铁冶金]