摘要：钢板表面裂纹是影响中厚板质量的主要缺陷，星裂是Q460C钢板主要的裂纹类型，通过调查分析和现场试验，摸清了裂纹的产生机理。经过采取相应措施，使裂纹得到有效控制。

ABSTRACT Surface star crack is the main defect affecting the quality of Q460C billet for a long time.The occurring mechanism have been foung through the investigation and local test for recent two years .The crack has been controlled effectively with the relevant measures.