P 520 - Status report on research and application of active media-based sheet metal forming

P 523: Construction and operation of a centre for metallic construction methods zmb The aim of the research project P523/A160 Establishment and operation of a centre for metallic construction methods - zmb of the Forschungsvereinigung Stahlanwendung e.V. (FOSTA) and the Forschungsvereinigung der Arbeitsgemeinschaft der Eisen- und Metallverarbeitenden Industrie e.V. (AVIF) was to promote the initiative to intensify the interdisciplinary cooperation of 6 university institutes of the RWTH Aachen in the field of steel research and application. Suitable work opportunities were to be created for them in a centre, thus also providing the prerequisites for a joint training, research and development operation. As the new zmb building itself was to be a demonstration object for new construction methods in steel, the planning, development and approval of this construction method and the execution had to be carried out and synchronised in such a way that the desired solution was ultimately achieved in technical, scheduling and financial terms. The report describes the special features of the planning and development, shows how the co-operation between the participating university institutes works and presents the first successes of the joint training, information and research and development activities. RESEARCH ASSOCIATION STAHLANWENDUNG e.V. Publication: 2004 Authors: Prof. Dr.-Ing. Dr. h.c. G. Sedlacek, Dr.-Ing. Ch. Heinemeyer

P 526 - Joint welding of high-strength sheet steel for car body construction In the context of lightweight automotive construction, high-strength steel materials are increasingly being used in the structure and outer skin. The integration of formed components made of high-strength steel grades into the car body is not yet possible in some cases in terms of welding technology, as the high carbon equivalents of the materials lead to significant seam hardening. The aim of the project was to develop and qualify a laser beam fusion welding process for joining high-strength steel sheets in car body construction. The seam hardening resulting from the high carbon equivalent and the high cooling rate was to be reduced by localised seam post-heating integrated into the process as far as possible in order to increase the energy absorption capacity of the joint. While the volume output of heat treatment processes with microplasma torches or diode lasers is limited by the melting of the workpiece surface, the energy input in inductive heat treatment takes place via the material volume. For this reason, an induction system was used for process-integrated heat treatment. Based on the investigations, a significant increase in seam ductility could be demonstrated for this process in some cases, depending on the material. RESEARCH ASSOCIATION FOR STAHLANWENDUNG e.V. Publication: 2004 Authors: Prof. Dr.-Ing. Dr.-Ing. E.h. mult. Dr med. h.c. H. Haferkamp, Dr.-Ing. Bunte, Dr.-Ing. P. Cordini

P 528 - Assessment of wear behaviour and determination of characteristic values for the selection of plastic mould steels suitable for stresses The stress-appropriate selection and thus the justified use of materials is based on knowledge of the stresses and stress resistance. Despite the great economic importance of the use of tool steels for plastic moulds for injection and compression moulding of plastic parts, where different tribological systems combined with corrosion and temperature stresses are effective, there is a great lack of knowledge in this area. A prerequisite for the safe use of materials are easily determined, reliable and stress-relevant characteristic values to describe the wear properties for the various stresses that occur during the processing of plastics. In close co-operation with steel manufacturers, manufacturers of different coating systems, representatives of the plastics processing industry, the chemical industry and two research institutes, characteristic values were developed using mechanism-oriented model testing equipment that describe a wide range of stresses. The use of such tribological test chains allows an evaluation of the material behaviour under different stresses. For the user, this makes it possible to analyse the material behaviour under changing stress conditions and to derive limit values for the selection of suitable steels. The material manufacturer is provided with a method for fast and cost-effective evaluation of known or newly developed materials. The characteristic values were compared with system-related test results. The influence of temperature on the wear behaviour of tool steels, which was previously only insufficiently known, was investigated in a heatable test rig under abrasive stress and corresponding characteristic values were also developed. An existing computer-aided database system for tribological parameters was expanded and adapted to the database systems commonly used today. The characteristic values developed were integrated into the system. The system allows an evaluation of the wear behaviour in a wide range of stresses. The database developed is partly a component of the first expansion stage of the StahlDat materials and steel database (www.stahldat.de) made available on the Internet by the VDEh Steel Institute. The availability of information is often the decisive criterion for selection in the increasingly fierce competition between materials. The results of the research project eliminate an information deficit and provide valuable information for material optimisation and future material developments. Authors: J. Kurzynski, T. Ümit, M. Pohl, M. Mola, R. Höhner Publication: 2006