测试了热镀锌钢板的力学性能和模拟成形性能,用扫描电镜观察试样拉伸变形后表面镀层变化情况,分析讨论了锌层对成形性的影响。结果表明:锌层产生横向裂纹是影响热镀锌钢板成形性的主要原因,锌层对r值有一定的影响,锌层厚度越大,r值降低的幅度越大。热镀锌钢板的扩孔率比冷轧裸板的扩孔率低10%~20%;FLC值降低5%左右(绝对值)。

The mechanical properties and simulating forming parameters of hot-dip galvanized steel sheets were evaluated. The scan electron microscope was used to observe the change of coating appearance of the tensile specimen with deformation. The influence of zinc coating on forming properties was analyzed and discussed. The result indicated that zinc coating appearing cross crack was the main cause to influence the forming properties of hot-dip galvanized steel sheets. Zinc coating affected the r value in a way,and the more its thickness increased,the more the r value decreased. The hole expanding rate of hot-dip galvanized steel sheets was lower 10%-20% than the cold-rolled bare steel sheets,and its FLC value decreased about 5% (absolute value).