The Influence of Lubricant and Sheet Thickness of 1.4376 During Deep Drawing

Abstract

Abstract

This work is concerned with the influence of lubricant, sheet thickness, position of production during sheet metal forming (deep drawing) on mechanical properties. The deep drawing process was carried out on a BUP-600 instrument using the Erichsen method, which uses a 20 mm diameter ball draw bar. The individual forming tests were carried out on 1.4376 plate with thicknesses of 1.5 mm and 1 mm. The drawing of the sheets was carried out with and without lubricant to assess the effect of the lubricant on the resulting properties. The actual forming results of the plates were verified by FEM analysis in AutoForm software, which pointed out the critical areas on the part. These specified locations were further subjected to mechanical property measurements. As shown in this work, the areas of sheet metal forming showed significant strengthening, which was reflected by an increase in mechanical properties at each location. The difference in mechanical properties between the unformed area of the sheet metal and the area on the sheet metal that was formed by deep drawing was up to 63% (Vickers hardness, indentation modulus). The lubricant had a significant impact on the drawing process; when applied, both the drawing distance and the force increased by approximately 25%. This can result in additional cracking of the sheet metal parts. This research has significant implications for the deep drawing of sheet metal in practice, pointing out the issue of critical points that need to be further accounted for and possibly eliminated or at least minimized. Plastic deformation occurring during deep drawing leads to an increase in material hardness and tensile strength. As a result, the formed parts achieve improved stiffness and load-bearing capability. The study contributes to a better understanding of how strain hardening can be maximized in critical regions of the drawn part without inducing fracture. Furthermore, the research describes the influence of sheet thickness variation during the drawing process, which is essential for maintaining the structural integrity of the component. The study further emphasizes the significance of lubrication and friction conditions in reducing the forces required for drawing, thereby preventing crack initiation and surface defects on the drawpiece.