Kuzmin S. Improvement of thermo-strengthening modes for grinding balls using rolling heating in purpose to enhance the quality and operational life

Рurpose - the improving of quality features and the span life of the rolled grinding balls made of low-alloy steels by means of forming an optimal structural condition due to improving of thermal hardening modes using rolling heating. Object - the phase-structural transformations during cooling from in steels which are required to have high abrasive-corrosive and impact-abrasive -corrosive wear resistance. The subject - the processes of formation of high wear resistant microstructure in grinding balls made of high-carbon low-alloy steels due to thermal hardening using rolling heating. Methods - optical microscopy, transmission electron microscopy, XRD, thermal analysis, magnetometric analysis, mechanical properties testing, wear resistance testing, computer simulation, mathematical statistics. Novelty - for the first time the continuous cooling diagrams of decomposition austenite in steels are built; the new refined classification of bainite morphology types observed in M74, 75Г2С and 75ХГСМ steels is proposed; new data of bainite substructure features of high-carbon low-alloyed steels are obtained; it is found that cooling up to Ms temperature affects the rising of austenite stability to bainite transformation at 250-400 °C in M74, 75Г2С and 75ХГСМ steels; for the first time new data about the influence of microstructural gradient on bulk abrasive-corrosive and impact-abrasive-corrosive wear resistance of grinding balls made of steels studied are obtained.