硬线钢拉拔断裂机理及连铸工艺优化  

Mechanism of drawing fracture of hard wire steel and optimization of continuous casting process

作　　者：杨文[1] 张彦辉 张立峰 江金东[3] 伍从应 YANG Wen;ZHANG Yan-hui;ZHANG Li-feng;JIANG Jin-dong;WU Cong-ying(School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China;State Key Laboratory of Metastable Materials Science and Technology,Yanshan University,Qinhuangdao 066004,Hebei,China;Department of Manufacturing Management,Shougang Shuicheng Iron and Steel(Group)Co.,Ltd.,Liupanshui 553028,Guizhou,China;Department of Steelmaking and Rolling,Shougang Shuicheng Iron and Steel(Group)Co.,Ltd.,Liupanshui 553028,Guizhou,China)

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004 [3]首钢水城钢铁(集团)有限责任公司制造管理部,贵州六盘水553028 [4]首钢水城钢铁(集团)有限责任公司钢轧事业部,贵州六盘水553028

出　　处：《钢铁》2021年第9期74-79,87,共7页Iron and Steel

基　　金：国家自然科学基金资助项目(51874031,U1860206,51725402);中央高校基本科研业务费资助项目(FRF-BD-20-04A);河北省省级科技计划资助项目(20591001D)。

摘　　要：硬线钢除了要求良好的力学性能,还要求良好的加工性能,但硬线钢盘条在拉拔过程中常发生断丝,给加工的连续性带来巨大危害。为了减少硬线钢的拉拔断丝,对其拉拔断裂机理进行了研究,并开展了相应的连铸工艺优化。首先对82B硬线钢拉拔断丝试样进行了分析,通过对断裂试样的断口和纵剖面分析,结合对应的连铸坯内部质量检测,得出连铸坯中心缺陷及偏析对硬线钢拉拔断裂的影响机制为促进了盘条中心渗碳体膜的生成,导致了裂纹的产生和扩展。然后通过施加电流为350A、频率为6.0Hz的连铸凝固末端电磁搅拌,降低浇铸时钢水过热度至30℃以下等措施,82B硬线钢连铸坯中心缩孔和中心偏析度分别降低至0.5级和1.08以下,82B硬线钢拉拔断丝率由优化前的10~15次/百t显著下降到4~5次/百t。Hard wire steel requires not only good mechanical properties,but also good processing properties.However,wire breakage often occurs in the drawing process of the wire rod of hard wire steel,which brings great harm to the continuity of processing.In order to reduce the wire breakage during the drawing of hard wire steel,the drawing fracture mechanism was studied,and the optimization of the corresponding continuous casting process was carried out.The drawing fractured wire sample of 82 Bhard wire steel was analyzed firstly.Through the analysis on the fractograph and longitudinal section of the fracture specimen,combined with the internal quality inspection of corresponding continuous casting billet,the influence mechanism of central defects and segregation of billet on drawing fracture of hard wire steel was obtained,which promoted the formation of cementite film in the center of wire rod and led to the generation and propagation of cracks.Then,by applying final electromagnetic stirring(F-EMS)at the solidification end of continuous casting with current of 350 Aand frequency of 6.0 Hz,and reducing the superheat of molten steel to below 30℃,the central shrinkage and central segregation of 82 Bhard wire steel billet were reduced to 0.5 and 1.08,respectively,and the wire breaking rate of 82 Bhard wire steel was significantly reduced from 10-15 times per 100 tons before optimization to 4-5 times per 100 tons.

关 键 词：硬线钢 拉拔断裂 缩孔缺陷 中心偏析 钢水过热度 末端电磁搅拌 

分 类 号：TF777[冶金工程—钢铁冶金]