Influence of Zinc Layer on Forming Limit of Galvanized Sheet DX51D+Z and its Potential for Enhancement in Forming
In order to study the forming effect of zinc layer on galvanized sheet DX51D+Z,the FLC(Forming Limit Curve),which is represented by the primary and secondary limit strain points during stamping failure,is detected by a three-dimensional optical strain measuring system.It is found that zinc layer has a certain negative effect on the formability of galvanized sheet.Under the specific strain state,the forming limit of galvanized sheet DX51D+Z is 5％-12％lower than that of the substrate with zinc layer removed.By observing the strain distribution of relevant points,it is found that the forming of galvanized steel sheet is significantly affected by lubrication conditions,and three layers of 0.05 mm polyethylene and 0.1 mm Vaseline can be used to improve that.The experimental results show that the improvement of lubrication conditions can effectively promote the uniform distribution of strain in the forming vault of galvanized DX51D+Z,and the ultimate principal strain is increased by about 9％.
万方数据
维普
