合金化镀锌板的镀层脱落分析

跟踪拍摄合金化镀锌板双球冲成形时的镀层脱落过程，发现双球冲行程变化影响镀层脱落时间、部位与程度。结合自行开发的镀层自动评价系统分析镀层脱落程度，表明双球冲行程会影响镀层应变，镀层脱落程度与镀层应变有关。脱落主要发生在压应变区域，压应变越大，脱落程度越大。对各变形阶段应变进行有限元仿真，对比镀层的实际脱落过程，进一步发现压应变对镀层脱落的影响关系：只有压应变增大到某极限值，镀层才开始脱落；压应变继续增大，脱落继续且程度加大；压应变到达最大值之后再减小，脱落过程随即中止。

GALVANNEAL COATING EXFOLIATING ANALYSIS OF GALVANNEALED SHEET STEEL

During double reverse olsen's forming, the galvanneal coating exfoliating is shot in multi burst mode by a camera, which shows that the exfoliating occurring time,location and amount are affected by the change of punch stroke distance. The self-developed auto rating system is used to evaluate the grades of coat exfoliating. It can be found that the compress strain of galvanneal coating has a relationship with punch stroke distance, and exfoliating behavior has a corresponding relationship with the compress strain. The exfoliating mainly occurs at the compress strain regions. The greater the strain is, the larger exfoliating amount is. The strains at different stages are stimulated by the means of FEM in order to compare actually exfoliating process. The results show the interesting relationship between exfoliating and strain, that is, the exfoliating occurs only when compress strain exceeds a certain limit. With the increasing of strain, the exfoliating amount becomes greater and greater. And when strain reaches its maximum and declines, the exfoliating would stop soon after.