摘要
分析了55SiCr弹簧钢丝矫直过程中发生断裂的原因,发现其中1圈钢丝表面局部区域存在锯齿状缺陷。取缺陷位置试样进行检验,结果显示裂纹两边局部增碳,存在网状渗碳体;裂纹中的物质Na含量较高,与保护渣成分相近。经分析认为,连铸浇铸中后期结晶器液面波动异常,保护渣卷入钢水导致成品表面局部增碳,进而造成矫直过程中发生断裂。通过严格执行保护渣勤加、少加和均匀加的操作制度,保持拉速1.8 m/min,水口浸入深度控制在110 mm左右,保持水口严格对中等措施,使后续生产过程结晶器液面波动范围控制在±5 mm范围内,保护渣卷入问题得到有效控制。
The fracture causes of 55SiCr spring steel wire during straightening were analyzed.It was found that there was serrated defect on the surface of one coil of steel wire.The results show that there is local carburization and network cementite on both sides of the crack;and the content of Na in the crack is higher,which is similar to that of mold flux.It is considered that the mold liquid level fluctuation is abnormal in the middle and late stage of continuous casting,and the mold flux is involved in the molten steel,which directly leads to local carburization on the surface of the finished product,and then causes fracture in the straightening process.By measures of strictly implementing the operation system of frequent,less and even addition of mold flux,keeping the casting speed of 1.8 m/min,controlling the submergence depth of nozzle at about 110 mm,and keeping the nozzle strictly in the middle,the fluctuation range of mold liquid level in the follow-up production process was controlled within±5 mm,then the mold flux involvement is effectively controlled.
作者
孙俊喜
李金波
靳国兵
郝志超
程鹏飞
Sun Junxi;Li Jinbo;Jin Guobing;Hao Zhichao;Cheng Pengfei(Technical Center of HBIS Group Hansteel Company,Handan 056015,Hebei)
出处
《河北冶金》
2021年第6期69-72,共4页
Hebei Metallurgy
关键词
弹簧钢
表面缺陷
矫直
网状渗碳体
保护渣
增碳
结晶器液面
spring steel
surface defects
straightening
network cementite
mold powder
carbon addition
mould level
