厚规格热镀锌板折弯开裂分析及改进措施

Cause analysis and improvement measures for bending cracks appeared on thick hot-dip zinc-coated plate

通过观察裂纹的宏观和微观形貌,对厚规格热镀锌板180°折弯开裂现象的原因进行分析。结果表明,基板中存在大尺寸珠光体团是主要原因。调整镀前基板的热轧工艺后,基板中的珠光体团尺寸由原来的40μm减小到10μm以下,180°折弯后镀锌板无开裂。

The cause of cracks formed on thick hot-dip zinc-coated plate after being bended for 180°was analyzed by observing the appearance and microscopic morphology of cracks.It was found that the main cause was the existence of large-sized pearlite cluster in the substrate.The size of pearlite cluster in substrate was decreased from 40μm to 10μm below through adjusting the hot-rolling process conditions of substrate prior to hot-dip coating,and there was no crack on hot-dip zinc-coated plate after bending 180°.