WASIAK Krzysztof Warsaw University of Technology

Spoluautoři SKOŁEK Emilia, ŚWIĄTNICKI Wiesław

In recent years, the researchers have been carrying out the intensive works which allowed obtaining a nano-sized carbide-free bainite or microstructure consisting of martensitic matrix and retained austenite. High strength and good service parameters of nano-sized carbide-free bainitic steels make, that they can competitive in comparison with highly alloyed martensitic steels [1]. High mechanical properties, such as hardness, tensile strenght while maintaining high ductility can also be obtained in steels a martensite/austenite mixture [2]. Heat treatment that allows obtaining the structure composed of martensite and carbon enriched austenite is called quenching and partitioning (Q&P) [3]. Our preliminary studies showed that metastable retained austenite in microstructure can improve wear resistance [4]. The aim of the work was to design the parameters of quenching and partitioning which allows to obtain microstructure consisted of martensite lath and inter-lath layers of retained austenite in 35SrSiMn5-5-4 steel. The parameters of the quenching and partitioning were chosen on the basis of computer simulations and dilatometric measurements. 35SrSiMn5-5-4 steel after quenching and partitioning process has been subjected to wear resistance tests. The results were compared with results obtained in the same steel subjected to quenching followed by tempering. The paper presents results of microstructure characteristic and comparative analysis of the results of wear resistance.