Analysis On Stamping Defects And Formability Characterization Of Tinplate

In recent years, with lower production costs and improved quality tinplate has been widely adapted. Thus tinplate is playing an important role in food and beverage packing industry. The canning industry in China has been developing rapidly. There are many problems concerning with the use of tinplate in industry. Therefore, the research on the formability of tinplate has become important more than ever.In this dissertation, the tinplates of Zhongyue Tinplate Company were studied. The typical defects of stamping parts appearing in the actual production were investigated, and the characterization model on formability of tinplate was developed.The contents of the study include the following main parts:(1) The tensile test and deep drawing test were employed to measure the properties of seven kinds of drawing tinplates. The table of the mechanical properties and the extreme deep drawing coefficient of plates was made, n and r values were used to characterize the deep drawing properties of tinplate. The characterization model is The results show that the accuracy of characterization model is very high. The model can be used to guide the production and to improve the efficiency.(2) The Erichsen test and forming limit test were applied to measure the properties of two kinds of bulging tinplates. The FLD (Forming Limit Diagram) and Erichsen value was successfully obtained. The relationships between them were analyzed and the Erichsen value was used to characterize the FLDo.(3) The mechanical tensile test and expanding test were applied to measure the properties of six kinds of flanging tinplates. The mechanical properties of the plates were obtained. The influence of thickness, strength, elongation and n value on expanding value was analyzed and the corresponding curves were plotted. The results showed that the elongation was affected significantly by the expanding value. Therefore the elongation was used to characterize the flanging properties of tinplate.(4) According to the microstructures, mechanical properties, hole-flanging properties and SEM microstructures on fractures, the causes of defects were found. The results showed that the defects of tin and food cans were very likely to be caused by the low accuracy of die or the poor lubrication. The defects of spray cans were possibly caused by the low formability of the blank.