Thermal influences during rotary draw bending of tubes from stainless steel

Rotary draw bending of tubes is a widely used forming process. Tubes made of stainless steel e.g. from AISI 304 (X5 CrNi 18 9) are used in exhaust systems, in the food industry or to guide chemicals. The formability of this austenitic stainless steel is high, because of its high work hardening.. The work hardening is caused by the temperature depending formation of martensite. The temporal temperature progressions as well as the local heat distributions have to be considered for the simulation of the bending process. The flow curves of AISI 304 were gained under nearly isothermal conditions. Other input Data were taken from literature. The results of the thermal coupled FE-Simulations compared to the results from practical experiments showed, that the temperature could not be calculated with good accordance. The reasons can be in simplifications in the FE-model. (C) 2014 Published by Elsevier Ltd.