The Analysis on the Stamping Formability of High Strength Steel

Recently the high strength steel has been applied in the automotive more and more widely. In this study, the effect of blank shape on the formability of an automotive part was analyzed. The three kinds of blank shapes were chosen, including a rectangular shaped blank, a blank with two corners cut straightly and a blank with two corners cut in curve. The effect of the variable blank holder force on the formability was studied. The four kinds of variable blank holder force were applied. The blank shape in this part is the blank with two corners cut curve. The results show that the blank with two corners curve is the most suitable. And the blank holder force from 1000 kN to 1500 kN is the most useful for the formability.

Study on Deformation Law of Drum-Shaped Blank and Collapse Defect in Rolling Process

Based on the FEM software simufact.forming, a finite element model of the radial-axial ring rolling for one ring product was constructed and the rolling process under different drum-shaped blanks were simulated in this paper, which revealed the variation of drum-shaped blank in the rolling process, analyzed the formation process and further proposed measures of eliminating collapse defect. The results show that the drum disappearing rate in initial rolling stage is greater than in later stage and it becomes increasingly difficult to disappear, which leads to collapse defect in the end. The drum-shape can be reduced by greater radial feed in initial rolling stage in the case of small drum-shape or rounding before rolling on ring rolling machine in the case of large drum-shape for avoiding collapse defect. The results provide valuable guiding significance for practical production.

Simulation of Ring Blank Drawing by Finite Element Method

Ring-shaped oil seals used in automobiles are usually manufactured by the press drawing and the press blanking considering the shape and the use application. In this process of manufacturing, the material availability is quite low because the central region part is cut from the product and becomes the waste material. We propose the forming method by the press drawing using a ring-shaped blank for the metallic part of the oil seal in order to improve the material availability and reduce the number of processes. In this research, the forming accuracy using the ring-shaped blank was investigated by the forming simulation. As the result, when the knockout was fixed in order to generate the sufficient bottoming by the punch, it was found that the bottom part can be formed flatly and the angle part can be formed almost right. Furthermore, it was found that the inside diameter of the formed product is proportional to the inside diameter of the blank except the case when the bottom part of the formed product is small. Hence, the required inside diameter of the ring-shaped blank can be calculated with the proportional relationship.