摘要
针对SCR7000工艺生产低氧光亮铜杆的扭转裂纹问题,采用SEM+EDS、OM等研究了铜杆中的杂质元素,中心与边部的晶粒尺寸及硬度差异,铜坯凝固组织异常等关键影响因素对扭转裂纹的影响。结果表明:铜杆扭转裂纹中存在Fe、Ni、Cr、Si等杂质元素的局部富集,产生了应力集中,诱导了铜杆表层的扭转裂纹。分析认为,这些杂质元素主要来自浇包、过滤器及钢溜嘴等材料的熔损;铜杆中心部位的平均晶粒尺寸、硬度与边部的差异大,导致扭转裂纹敏感性大,这是铜坯的入轧温度、轧制过程的铜杆冷却不合适、轧机与铜坯间的摩擦作用以及SCR7000工艺多道次轧制所致;铸轮结垢的严重程度与扭转裂纹的发生率存在明显的正相关关系,这是严重的铸轮结垢导致铜坯凝固组织异常所致。
In view of the torsional crack problem of low oxygen bright copper rod produced by SCR7000 continuous casting and rolling,Scanning Electron Microscopy(SEM)+Energy Spectrometer(EDS),Optical Microscopy(OM)were used to study the influence of the impurity elements in the copper rod,the grain size and hardness difference between the center and the edge,solidification structure of copper billet structure abnormality and other key factors affecting the torsional crack.The results show that there is local enrichment of Fe,Ni,Cr,Si and other impurities in the torsional crack of copper rod,resulting in stress concentration and induced torsional crack on the surface of copper rod.The analysis shows that these residual elements are mainly from the melting loss of pouring ladle,filter and steel pouring nozzle.The average grain size of the central part of the copper rod,the difference between hardness and the edge is large,leading to the sensitivity of the torsion crack is large,which is caused by the rolling temperature of the copper billet,the cooling of the copper rod in the rolling process is not appropriate,the friction between rolling mill and copper billet,the multi pass rolling of SCR7000 continuous casting and rolling.There is an obvious positive correlation between the severity of casting wheel scaling and the incidence of torsional crack,which is caused by the abnormal solidification structure of copper billet caused by serious casting wheel scaling.
作者
刘鹏
郑万
沈韶峰
明江勇
梁震江
王爽
张惠荣
LIU Peng;ZHENG Wan;SHEN Shaofeng;MING Jiangyong;LIANG Zhenjiang;WANG Shuang;ZHANG Huirong(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei Provincial Key Laboratory for New Process of Ironmaking and Steelmaking,Wuhan University of Science and Technology,Wuhan 430081,China;Huangshi Shengxiang Copper Industry Co.,Ltd.,Huangshi 435000,China)
出处
《有色金属工程》
CAS
北大核心
2023年第4期29-37,共9页
Nonferrous Metals Engineering
关键词
SCR7000
铜杆扭转裂纹
杂质元素
晶粒尺寸均匀性
铜坯凝固组织
SCR7000
torsional crack of copper rod
impurity element
grain size uniformity
solidification structure of copper billet
