包晶钢连铸坯角部裂纹缺陷产生原因分析与预防
|
摘要
针对中碳包晶钢凝固过程中铸坯角部裂纹缺陷问题,采用低倍酸洗、金相显微镜和扫描电镜能谱分析仪等手段,结合生产工艺,对裂纹缺陷产生原因进行详细分析。结果表明:裂纹主要产生于铸坯角部振痕波谷应力比较集中位置,主要以晶间裂纹为主。通过采取优化钢水化学成分和连铸二次冷却工艺,严格控制辊缝精度和提高矫直段前铸坯边角部温度等措施,可以有效预防铸坯角部裂纹缺陷产生,经统计,裂纹缺陷率由原来的1.27%降低到了0.24%。
Aiming at the corner crack defect of medium carbon peritectic steel during solidification,the causes are analyzed in detail by means of low-power pickling,metallographic microscope and scanning electron microscope energy spectrum analyzer on the production process.The results indicated that the cracks mainly occured in the corner of the billet where the stress was concentrated and mainly were in the intergranular cracks.By optimizing steel content and secondary cooling process,strictly controlling the roll gap accuracy and improving the edge and corner temperature of the billet before straightening section,the corner crack defects of the billet could be prevented.It was proved by statistics that the crack defect rate was reduced from 1.27% to 0.24%.
Aiming at the corner crack defect of medium carbon peritectic steel during solidification,the causes are analyzed in detail by means of low-power pickling,metallographic microscope and scanning electron microscope energy spectrum analyzer on the production process.The results indicated that the cracks mainly occured in the corner of the billet where the stress was concentrated and mainly were in the intergranular cracks.By optimizing steel content and secondary cooling process,strictly controlling the roll gap accuracy and improving the edge and corner temperature of the billet before straightening section,the corner crack defects of the billet could be prevented.It was proved by statistics that the crack defect rate was reduced from 1.27% to 0.24%.
引文
[1]林建农.微合金化钢连铸坯高温塑性研究[J].技术讨论,2006,12(5):21-23.
[2]Mintz B,Yue S,JonasJ J.Hot ductility of steels and its relationship to the problem of transverse cracking during continuous casting[J].Int Mater Rev,1991,36(1):187-188.
[3]耿明山,王新华.Cu、As和Sn对低合金钢连铸坯第三脆性区的影响[J].技术讨论,2009,4(4):434-435.
[2]Mintz B,Yue S,JonasJ J.Hot ductility of steels and its relationship to the problem of transverse cracking during continuous casting[J].Int Mater Rev,1991,36(1):187-188.
[3]耿明山,王新华.Cu、As和Sn对低合金钢连铸坯第三脆性区的影响[J].技术讨论,2009,4(4):434-435.