多线切分直接轧制带肋钢筋屈服强度波动研究  

Study on fluctuation of the yield strength of ribbed bar produced by direct rolling with multi-strands splitting technology

作　　者：徐兵伟 邸全康 詹卫金 刘德乾 王伟 冯江波 XU Bingwei;DI Quankang;ZHAN Weijin;LIU Deqian;WANG Wei;FENG Jiangbo(Shougang Changzhi Iron and Steel Co.,Ltd.,Changzhi 046031,China;Research Institute of Technology,Shougang Group Co.,Ltd.,Beijing 100043,China)

机构地区：[1]首钢长治钢铁有限公司,山西长治046031 [2]首钢集团有限公司技术研究院,北京100043

出　　处：《轧钢》2023年第6期118-121,共4页Steel Rolling

摘　　要：采用连铸坯直接轧制生产带肋钢筋时,由于连铸坯心部温度高于表面温度,在多线切分工艺状态下,表现出切分中线的温度高于边线温度,导致中线轧件的屈服强度偏低。为此,分析了直接轧制状态下连铸坯心表温差对产品尺寸、金相组织和屈服强度的影响,并提出了改进措施,最终实现钢筋产品力学性能的稳定。结果表明:多线切分直接轧制生产带肋钢筋时,相比于边线轧件,中线轧件的温度高30℃左右,使得其直径减小约0.1 mm,屈服强度降低5~10 MPa,晶粒度粗大且出现魏氏组织;通过优化多线切分孔型系统的预切分和切分孔型,增大中线轧件的孔型面积,实现了多线切分直接轧制中线和边线成品轧件尺寸均匀稳定;通过对多线切分中线轧件的轧后冷却,使得中线轧件与边线轧件温度趋于一致,保证了中线轧件晶粒均匀细小且避免出现影响性能的魏氏组织,将中线和边线轧件屈服强度差异控制在5 MPa之内。The center temperature of the continuous casting billets is higher than the surface temperature when the direct rolling process is used to produce ribbed bars,so the temperature of the centerline rolled piece is higher than the edge lines rolle piece,resulting in a lower yield strength of the centerline rolled piece.Therefore,the influence of temperature difference on product size,metallographic structure and yield strength of continuous casting billet under direct rolling condition was analyzed,and the improvement measures were put forward to realize the stability of mechanical properties of products.The results show that the temperature of the centerline rolled piece is about 30℃higher than that of the edge lines rolledpiece when ribbed bars are produced by multi-strands splitting and direct rolling,the diameter of the centerline piece is reduced by about 0.1 mm,the yield strength is reduced by 5-10 MPa,the grain size is coarse and the Widmannstatten structure appears.By optimizing the size of pre-splitting and splitting pass in the multi-strands splitting pass system,the pass area of the centerline rolled piece is increased,and the size of the centerlineand the edge lines rolled pieces are uniform and stable.By performing post cooling on centerline rolled pieces in the multi-strands splitting rolling,the temperature of the centerline rolled piece and the edge lines rolled pieces tend to be the same,the grain size of the centerline rolled piece is uniform and fine,and the Widmannstatten structure which affects the performance is avoided.The difference of yield strength between the centerline rolled piece and the edge lines rolled pieces is controlled within 5 MPa.

关 键 词：带肋钢筋 多线切分 直接轧制 节能减排 中线轧件 边线轧件 魏氏组织 屈服强度 

分 类 号：TG335.64[金属学及工艺—金属压力加工]