Comparative Study on Shearing Edge Quality Influence of the Change of Tool Geometry in Fine-Blanking for Ferrous Metals

摘要

This paper presents mainly a comparative study of the quality influence of tool geometry change inrnfine-blanking for two common ferrous metals. This is because intensive investigations on different effects of thoserncritical factors for different kinds of popular and applicable material are rare and limited. However, the mostrnnoticeable change of the tool geometry during the operation will be the severe variation of the nose radius of thernpunch. Therefore, a tailor-made experimental study was carried out to investigate the relationship between thernpunch nose radius and the shearing edge quality, such as blanked edge finish, burr height and die-roll height, duringrnfine-blanking for two types of the most frequently used ferrous metals, which are the Low Carbon Steel (SS400) andrnStainless Steel (AISI316L). Five punches with each specified nose radius (Rp), 0.00mm, 0.25mm, 0.50mm,rn0.75mm and 1.00mm, together with the two selected blanking materials (Low Carbon Steel SS400 and StainlessrnSteel AISI316L) were employed throughout the study. Subsequently, features of the sheared edge surfaces and datarnof each experiment were observed and captured for further analysis in this research. Eventually, findings show thatrnan increase of punch nose radius produces a higher percentage of fracture of blanked edge and increases the amountrnof burr height. As a conclusion, it is found that Low Carbon Steel does provide better edge surface finish with higherrnpercentage of sheared area and less burr height than that of Stainless Steel. Also, this further agrees with the Prof. F.rnBirzer [7] that the higher the content of hard and brittle phases in the structure, the more the fine-blanking suitabilityrnof the material is reduced.