82B盘条脆断原因分析与预防  

A study on the cause analysis and prevention of brittle fracture of 82B wire rod

作　　者：张亚君[1] 杨红来[1] 黄小山[1] 张春斌[1] 刘辉杰[1] ZHANG Yajun;YANG Honglai;HUANG Xiaoshan;ZHANG Chunbin;LIU Huijie(Xinyu Iron and Steel Group Co.,Ltd.,Xinyu 338001,China)

机构地区：[1]新余钢铁集团有限公司,江西新余338001

出　　处：《江西冶金》2020年第4期33-37,42,共6页Jiangxi Metallurgy

摘　　要：82B盘条在经拉拔后表面出现横向裂纹及脆断的现象,严重影响产品质量和生产节奏,为了减少脆断的发生,采用金相显微镜及扫描电镜对脆断的82B进行取样分析。结果表明:脆断样局部表面有块状碳化物及网状渗碳体等异常组织存在,并且裂纹源位于异常组织处,试样纵断面上有大型C类和少量B类保护渣类夹杂物,故表明这种脆断主要是由连铸卷渣造成铸坯表面局部增碳从而大量析出网状渗碳体引起的。通过控制连铸加渣均匀性、浸入式水口合理的插入深度及采用恒拉速浇注、钢水液面稳定等手段来稳定连铸操作,减少卷渣产生的钢坯表面局部增碳现象,有效地减少了脆性断裂的发生。The appearance of transverse cracks and brittle fracture on the surface of 82B wire rod after it was drawn seriously had impact on product quality and production rhythm.In order to reduce the occurrence of brittle fracture,etallographic microscope and scanning electron microscope were used to sample and analyze 82B wire rod.The results showed that there were some abnormal structures on the local surface of brittle fracture sample,such as massive carbide and network cementite,and the crack source was located at the abnormal structure.There were large C and small B inclusions on the longitudinal section of the sample.Therefore,it was concluded that the brittle fracture was mainly caused by local carburization on the slab surface derived from continuous casting slag,which resulted in a large number of network cementite precipitation.By controlling the uniformity of slag addition,reasonable insertion depth of submerged nozzle,constant casting speed and liquid steel level stabilization,the operation of continuous casting could be stabilized,which could reduce the local carburization on the slag surface and effectively reduce the occurrence of brittle fracture.

关 键 词：82B盘条 脆断 夹杂物 网状渗碳体 

分 类 号：TG142.1[一般工业技术—材料科学与工程]