影响高强双相钢冷轧边部缺陷的因素及改进措施
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摘要
高强双相钢冷轧时,由于边部缺陷导致断带发生,严重影响产线的稳定运行。本文采用金相显微镜、扫描电镜、透射电镜等手段分析边部缺陷原因。结果表明:造成高强双相钢冷轧边部缺陷的原因主要有两种。一种原因是卷取时侧导板和带钢剐蹭,热轧卷边部质量不良遗传至冷轧;另一种原因是冷轧大变形时铁素体和马氏体相界面的形变不协调引发延性断裂,以及条带状马氏体自身的颈缩断裂。由此提出相应改进措施,一方面严格对中标线防止带钢跑偏、定期更换侧导板、加强冷轧原料上线检查管理;另一方面优化热轧组织,同时适当降低冷轧轧制压下率,改善冷轧边部缺陷。
The poor quality of the edge of the high-strength dual-phase steel after cold rolling resulted in multiple breakages, which seriously affected the stable operation of the production line. In this paper, metallographic microscope, SEM, TEM and other measures were used to analyze the reason for the poor quality of the edge. And results showed that there are mainly two types of causes. One reason is that the side guides in coiling process scratch the strip,and the defect on edge goes to cold rolling process. Another reason is the ductile fracture caused by unbalanced deformation between F and M phases during the large deformation period of coldrolling and the necking and cracking of martensite. Based on the study, counter measures are put forward. Firstly to strictly check the marking line to prevent off tracking of strip steel,periodically replace the side guides and strengthen the inspection and management for cold rolled raw materials. And to optimize hot-rolled structure, reduce reduction rate of cold rolling and improve edge defects of cold rolling products.
The poor quality of the edge of the high-strength dual-phase steel after cold rolling resulted in multiple breakages, which seriously affected the stable operation of the production line. In this paper, metallographic microscope, SEM, TEM and other measures were used to analyze the reason for the poor quality of the edge. And results showed that there are mainly two types of causes. One reason is that the side guides in coiling process scratch the strip,and the defect on edge goes to cold rolling process. Another reason is the ductile fracture caused by unbalanced deformation between F and M phases during the large deformation period of coldrolling and the necking and cracking of martensite. Based on the study, counter measures are put forward. Firstly to strictly check the marking line to prevent off tracking of strip steel,periodically replace the side guides and strengthen the inspection and management for cold rolled raw materials. And to optimize hot-rolled structure, reduce reduction rate of cold rolling and improve edge defects of cold rolling products.
引文
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[10]王占学.塑性加工金属学[M].北京:冶金工业出版社, 1991.
[2]尹翠兰. 1 000 MPa级热轧双相钢的微观组织及强化机制[J].金属热处理, 2016, 41(02):54-57.
[3]吝章国,熊自柳,刘宏强,等.合金元素对高强度汽车用钢板相变规律的影响[J].金属热处理,2016, 41(02):28-31.
[4]卢凤喜,黄璞.新日铁取向硅钢热轧边裂及其防止方法[J].中国冶金, 2006, 16(08):46-49.
[5]王畅,于洋,王林,等.高强IF钢冷轧过程轧裂原因及机理研究[J].金属材料与冶金工程, 2018, 46(01):25-28+33.
[6]陈伟,苏鹤洲.热轧板卷边裂成因浅析及控制[J].钢铁钒钛, 2008, 29(2):67-72.
[7]丁晔,孙维连,张云谦,等. 45钢管冷轧开裂原因分析[J].金属热处理, 2014, 39(04):142-144.
[8]谢军.冷轧高速断带问题探讨[J].金属材料与冶金工程, 2012, 40(03):42-44.
[9]王林,于洋,王畅,等.边部组织及切边工艺对低碳SPHC冷轧边裂的影响[J].中国冶金, 2014, 24(09):15-21.
[10]王占学.塑性加工金属学[M].北京:冶金工业出版社, 1991.