HRB335热轧带肋钢筋表面纵向裂纹原因分析

Analysis on the Cause of Longitudinal Crack on the Hot-Rolled Ribbed Bar Surface

采用铸坯低倍酸浸检验、金相检验、扫描电镜及能谱分析等方法对HRB335热轧带肋钢筋的冷弯表面纵向裂纹进行了综合分析,结果表明:产生表面纵向裂纹的主要原因是铸坯存在严重的皮下气孔和内部裂纹,在后期的热加工过程中与表面贯通,气孔或裂纹表面被氧化,造成轧制过程无法焊合。讨论了生产过程中铸坯皮下气孔及裂纹产生的原因,对其生产工艺的改进提出建议。

To find the main reason of longitudinal crack on HRB335 hot-rolled ribbed bar surface in cold bending process,continuously cast product macro-acid etching test,metallographic examination,scanning electron microscope and EDAX were carried out.It is regarded that the defect is mainly caused by serious subsurface blowholes and internal cracks in the cast product,which run through the surface in the later hot working process and is oxidized.As a result,the defects can not be welded in the rolling process and the cracks happen finally.The causes of subsurface blowhole and cracks in the production process were discussed,and some suggestions to improve the production process were given.