TY - CONF A1 - Rethmeier, Michael A1 - Suwala, Hubert ED - Bleck, W. ED - Raabe, D. T1 - Influence of crack-imperfections on mechnical properties of resistance spot welded ferritic-austenitic steel sheet combinations N2 - In order to respond to the challenge of the intensifying energy crisis and to meet customer requirements for automobiles, such as weight reduction for energy saving and enhancement of passenger safety, new materials have to be applied in the automotive industry. Modern Steel types with advanced mechanical properties and a complex microstructure are used. These Steel types have an increased susceptibility to weid cracking, especially during resistance spot welding. Since the influence of weid cracks on the mechanical properties of spot welded joints is not sufficiently known, specifications offen require crack-free welds. Therefore it is necessary to examine the actual effect of crack-imperfections in resistance spot welded sheets on its fatigue and impact behavior. The influence of cracks in the welding area of resistance spot welded dissimilar joints between a ferritic- and an austenitic FeMn-steel sheet has been studied. Investigations of crack-free welds and crack-afflicted welds with focus on fatigue strength were made according to the Wöhler fatigue test. The Investigation of the fatigue behavior of resistant spot welded sheets is done by analyzing the quotient of force and the oscillation amplitude. By comparing the stiffness curves and load cycles between a crack-free weid and weid with cracks. Beside the fact that it was nearly impossible to specifically produce crack-afflicted specimen by welding operations, there were later on found no significant influences of those cracks on fatigue life time behavior. T2 - 2nd HMnS -2nd International conference on high manganese steels 2014 CY - Aachen, Germany DA - 31.08.2014 KW - Resistance spot welding KW - Frequency KW - Stiffness KW - Advanced high strength steels KW - FeMn-steels KW - Cracking KW - Defects PY - 2014 SP - A-107, 1-5 AN - OPUS4-32549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -