某厂低碳含B钢铸坯角裂缺陷改善措施

Improvement Measures for Corner Crack Defect of Low Carbon B-containing Steel Billet in a Factory

针对日钢1号板坯连铸机浇铸低碳含B钢过程出现的角裂缺陷问题,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,对角裂缺陷的产生原因进行详细分析。通过工艺对比试验,调整钢水成分、控制N含量、降低二冷强度、提高振频、减小振幅等方式,有效降低了角裂缺陷发生量,1号连铸角裂缺陷率由原来的10.2%降低至7.2%。经过理论计算,铸坯角裂缺陷与铸机机型构造有关,为后续生产含B钢工艺参数设定提供了建议。

Aiming at the problem of corner crack in the process of casting low-carbon B-containing steel by No.1 slab caster,the causes of angular crack are analyzed in detail by means of low power pickling,metallographic microscope and scanning electron microscope energy spectrum analyzer,combined with the production process.Through the process comparison test,the occurrence of corner crack defects is effectively reduced by adjusting the molten steel composition,controlling the N content,reducing the secondary cooling strength,increasing the vibration frequency and reducing the amplitude.The angular crack defect rate of No.1 continuous casting is reduced from 10.2%to 7.2%.Through theoretical calculation,the corner crack defect of billet is related to the model structure of caster,which provides suggestions for the setting of process parameters for subsequent production of B-containing steel.