Conception d'outils d'emboutissage en béton hydraulique

In the car industry, plastics are currently increasing. The iron and steel metallurgists have to offer new technical innovations leading to the cost reduction of sheet-steel forming. A first study showed that the cost reduction could arise from the manufacturing of deep-drawing tools used for the production of a hundred prototype cars. Hydraulic concrete tools coated with a polymer resin were able to deep-draw 16000 parts. Nevertheless, the wear of the resin and the strength of the interface between the resin and the concrete limit the performances of these tools. In order to reduce the cost, we achieved tools without surface product. A testing bench of wear by friction enabled us to characterize the surface properties. The tools have been tested on a deep-drawing line. With more than 600 deep-drawn parts, the tests showed that the tools can be used for the production of prototype cars. In order to extend their use to small or middle series (20 000 to 50 000 parts) improvements are necessary. First, the surface must have a lower roughness and present no defect, moreover, in order to reduce the rate of wear the surface hardness must be increased.