冶金因素对连铸小方坯角部纵裂的影响

EFFECT OF METALLURGICAL FACTORS ONFORMATION OF LONGITUDINAL CRACKS ATCORNERS OP CONTINUOUSLY CAST BILLET

通过生产统计分析、铸坯的金相检验和高温性能的测试,研究了冶金因素对A3钢连铸小方坯角部纵裂的影响。研究表明,1)当浇注温度较高时,含硫量与Mn/S比的影响十分显著,应将硫控制在S≤0.03％范围内。否则,在良好的操作条件下也难防止裂纹。当浇注温度较低时,对硫的控制范围可以放宽。2)含碳量在0.14～0.22％范围内,没有发现碳含量的增加对裂纹形成有明显的影响。

The effect of metallurgical factors on formation of longitudinal cracks at corners of A3steel billet was invastigated with statistical and metallographical analyses and high temperaturetesting. The following conclusions have been reached: 1) At high teeming temperature, the ef-fects of sulphur level and Mn/S ratio on cracks are signeficant. It is difficult to avoid crackformation even under good operation, unless the sulphur could be kept at ≤0.03%. Sulphur le-vel would be a little higher at lower teeming temperature. 2) There is no distinct effect onthe formation of cracks with the increase of C in the range 0.14～0.22.