题目：Understanding complex microstructures in modern steels
报告人： Wolfgang Bleck教授，RWTH Aachen University, Germany
Modern steel concepts aim at improved properties by tailoring the microstructure. Three trends are of major interest in present-day material development activities: the decrease of the structural length of microstructural constituents towards nanosized quantities, the increase of alloying level and hereby the interaction of different elements in enriched zones, more complex and adjusted robust processes activating several metallurgical mechanisms for controlled microstructure development.
This contribution provides examples for newly developed industrial steels for various applications. These include the control of process kinetics for multiphase microstructures and the microstructure property relationship of advanced high strength sheet steels. The forming capacity during quasistatic, dynamic and cyclic loading of multiphase steels will be discussed also considering real microstructures. Examples will be given by reflecting on some aspects of the nature of bainite in forging and bearing steels, the kinetics of damage in statically and dynamically loaded 1st and 2nd generation advanced high strength steels and the short crack growth in cyclically loaded gear steels.
Furthermore, recent developments for safety relevant components will be discussed as complex phase steels and press–hardening steels. The impact of boron alloying on phase transformation behavior and the microstructure development in hardenable steels will be highlighted. Possible fields of application for these materials are lightweight car bodies, damage-tolerant drive train components or offshore windmill gears and towers.