铸坯表面划伤在圆钢轧制过程中的演变研究

本文对方坯轧制圆钢过程中铸坯表面划伤演变规律进行了工业试验研究。首先统计了某钢厂常见的铸坯划伤类型，然后选取特征划伤铸坯进行轧制跟踪，最后对相应的圆钢进行酸洗和测量。结果表明：铸坯表面深度较浅的划伤经轧制后不会导致圆钢的表面缺陷；较深的划伤则会在圆钢表面形成三角口型的直线型裂纹，该类裂纹深度最大可达1.9 mm，呈间断性地分布在整个圆钢上，裂纹处的金相检测发现裂纹四周有明显的脱碳现象。

Study on evolution behavior of billet surface scratch in hot rolling of round bar

An industrial experiment was carried out to study the evolution behavior of billet surface scratch in hot rolling process of round bar.Scratch types were observed and classified statistically and typical billets with scratch were rolled into round bar which was tracked.The corresponding round bar was picked out and pickled and cracks on the round bar were measured.The results show that shallow scratch will not result in serious cracks on the round bar,deep scratch （over 1 mm） will be rolled and changed into triangle-gap type cracks and the depth of crack can reach up to 1.9 mm.Cracks discontinuously appear on the surface of round bar and decarburization is discovered around the crack.