The competition among sheet-metal-forming manufacturers in recent years has become more severe. Many manufacturers have survived by cutting their production costs. Increasing the formability, which could reduce the production costs, is the focus of many manufacturers and engineers. In the present research, to increase the formability over the limiting drawing ratio (LDR) in the cylindrical deep-drawing process, the application of oleophobic coating is proposed. An SUS304 (JIS standard)-stainless-steel cylindrical deep-drawn component was used as the investigated model. First, we applied the oleophobic coating in the sheet-metal-forming process, and tribology tests were carried out to examine the friction coefficients, which were reduced by approximately 60% compared with those of standard lubricant use (Iloform TDN81). Next, deep-drawing tests were performed to investigate the drawing ratio (DR). The LDR recommended in the past could be overcome, and it increased by approximately 12% with the oleophobic coating use. Finally, the deep-drawing mechanism using an extremely low friction coefficient was clarified as well. Based on these results, an oleophobic coating could be applied in the cylindrical deep-drawing process to increase the LDR. The results also clearly expose the multidisciplinary approach that combines an oleophobic coating application and the sheet-metal-forming process.

In recent years, the old-fashioned cylindrical cup shapes are still widely used, and there are many defects which could not be solved yet. In the present research, the classical earing defects, which are mainly caused by the material mechanical property of the anisotropic property of the material (R-value), are focused on. The multi draw radius (MDR) deep drawing die is applied and investigated to achieve nearly zero earing defects by encountering the R-value during the deep drawing process. Based on the experiments, in different directions in the sheet plane, the somewhat concurrent plastic deformation could be controlled, and the uniform elongated grain microstructure and uniform strain distributions on the cup wall could be achieved. Therefore, on the basis of these characteristics, the earing defects could be prevented, and the nearly zero earing defects could be achieved. However, to achieve the nearly zero earing defects, the suitable MDR die design relating to the R-value should be strictly considered. In the present research, to apply the MDR die for the medium carbon steel sheet grade SPCC cylindrical drawn cup, the following was recommended: the large draw radius positioned at 45° to the rolling direction and the small draw radius positioned along the plane and at 90° to the rolling direction. Therefore, in the present research, it was originally revealed that the nearly zero earing defects could be successfully performed on the process by using the MDR die application.

Earing has been a major issue in the deep-drawing process, especially for cylindrical cups. The additional work required to fabricate the cylindrical cup according to its specifications is frequently caused by these defects. Only a few methods have been developed to eliminate these defects, despite knowing the origin of these defects to be the material's anisotropic mechanical property (R-value). In this study, we proposed a zoning lubricant technique to achieve practically zero earing defects by applying a varied friction coefficient in relation to the R-value. This technique was examined based on experimental work and the finite-element method (FEM). The deep-drawing process for achieving practically zero earing defects was evident based on the FEM simulation findings. This resulted in practically no earing defects being discovered, and earing defects were avoided as a result of these characteristics. However, to accomplish almost zero earing defects, the proper design of zoning lubricant uses connected to the R-value should be properly considered. According to these findings, a smaller friction coefficient should be placed along the plane and at 90° to the rolling direction, whereas a larger friction coefficient should be positioned at 45° to the rolling direction. Furthermore, it was initially discovered in the current investigation that the use of zoning lubricant could successfully execute the procedure with nearly zero earing defects.