高强镀锌板表面发麻缺陷产生机理研究

Study of Mechanism of Pitting Defect on the Surface of High Strength Galvanized Sheet

高强镀锌板表面发麻缺陷形成根本原因在于镀锌板的锌层表面厚度不均匀,光整后表面粗糙度差距较大。锌层表面厚度不均匀形成的原因在于镀锌板表面存在较多的表层裂纹,该表层裂纹主要产生在冷轧工序。由于微观组织特点,钢板在轧制过程中抗开裂能力较低,导致冷轧高强钢板表面形成10μm的表层裂纹。结合CCT曲线的模拟分析发现,控制热轧钢板表层微观组织状态,可明显抑制高强镀锌板表面发麻缺陷的产生。

The root cause of the pitting defect on the surface of high strength galvanized sheet was that the thickness of the zinc layer on the galvanized sheet was not uniform,and the surface roughness was different to a great extent after skin rolling process.The reason for the uneven thickness of zinc layer was that there were many surface cracks on the surface of galvanized sheet,and the surface cracks were mainly generated in the cold rolling process.Due to the microstructural characteristics, the surface cracking resistance of the sheet during the rolling process was low,resulting in the formation of 10μm depth surface cracks of cold rolled high strength steel sheet.Combined with the simulation analysis of CCT curve,it was found that controlling the surface microstructure of hotrolled steel sheet could significantly inhibit the occurrence of pitting defects on the surface of high strength galvanized sheet.