Netrebko V. Scientific and technological bases of increase of mechanical and service properties of high-chrome cast iron

The object of research is the processes of formation and transformation of the carbide phase and the metal base and the change of properties of high-chromium cast -irons. The subject of the study is the laws of the influence of the chemical composition on the formation of the structure and properties of high-chromium cast-irons, as well as on the distribution of alloying elements in the casting state and their redistribution during the cooling of castings in the form and heat treatment. Methods of research - microstructural and local micro-roentgenospectral analyzes, hardness of HRC, HV and specific mass losses in different conditions. The results were processed using methods of mathematical statistics, factor analysis, correlation and regression analysis. The systematization of carbide phases and the addition in the sistem Fe-Cr-C have been made. The processes of formation of the carbide phase and the metal base at all stages of the technological process are investigated. The regression dependences of the distribution of the elements, mechanical and service properties of cast iron on the content of C, Cr, Mn and Ni in the casting state and after various types of heat treatment were obtained. Cast iron grades for different operating conditions are developed taking into account technological requirements. The mechanisms of the destruction of cast iron at the Rebinder effect and the pulp particles have been established. The results of the work were tested by the manufacturing and operating conditions of of parts at the enterprises: PP "STROYMASH", LLC "ZTMK" and LLC "TWINS-SERVIS LTD". Economic efficiency will amount to more than 3.18 million UAH for a year. The scope of application is engineering.