OPTIMIZATION OF TMO OF MODIFIED HEAT-RESISTANT CHROME BRONZES

Abstract

The paper presents the results of studies of the influence of technological factors during thermal and thermomechanical processing on the structure and properties of modified heat-resistant chrome bronzes obtained using mechanically fused submicrocrystalline ligatures with a high content of the main alloying component. The role of the heating temperature and the duration of exposure during quenching on the kinetics of chromium dissolution has been studied. An idea of the formation of physico-mechanical properties during aging of experimental bronzes depending on temperature and exposure time is obtained. The boundary conditions of plastic deformation during thermomechanical processing are determined and dependences are obtained to optimize the production process of alloys with maximum strength characteristics and heat resistance properties. The microstructure of alloys at all stages of TO and TMO has been studied. It has been established that heat-resistant chrome bronzes obtained using mechanically fused submicrocrystalline ligatures with a high content of the main alloying component, inheriting the microcrystalline type of base at all stages of processing, have a higher complex of physico-mechanical properties compared with classical BrX and BrXCr even after maintenance. By applying TMO and aging at 490-500 ^oC, it is possible to obtain a unique combination of strength and heat resistance characteristics, significantly increasing the life of electrical products, which is confirmed by production tests at leading machine–building enterprises of the Republic of Belarus.