棒材Q235B端头裂纹成因分析及改进措施

Analysis on the Causes of Crack at the End of Q235B Bar and its Improvement Measures

针对天钢Q235B棒材出现的端头裂纹,从冶炼、轧钢、剪切等环节进行了分析,找到了端头裂纹的产生原因。从冶炼过程中的拉速、冷却温度等关键工艺参数控制入手,解决了Q235B转炉直上坯料因为坯料脱方、内部对角裂纹造成圆钢端头开裂的质量问题,提高了圆钢合格率。

In view of the end crack in Q235B steel bar of Tianjin Iron and Steel Co. Ltd., the causes of the end crack are found through the analysis of smelting, rolling, shearing and other links,Strating with the control of key process parameters such as drawing speed and cooling temperature during smelting and casting process, the quality problem of end crack of round steel caused by internal diagonal crack in Q235B billets and off-square billets is solved, and the qualified rate of round steel is improved.