New Bainitic Steel for Cyclic Loaded Safety Parts with Improved Cyclic Material Behaviour

A bainitic forging steel, which enables the TRIP-effect, has been developed and can be used for lightweight-construction for forged components under cyclic loading. The high potential under cyclic loading conditions of the new generation of TRIP forging steels is shown and also the improved results under service loads, especially under overloads and misuse. A comparison of linear damage accumulations by Palmgren-Miner will depict the differences in characteristic damage sums between quenched and tempered and the new bainitic steel.For TRIP steels properties the process parameters are very important. Hence, the influence of the cooling conditions of TRIP will be discussed.