Myronova T. Development of a scientific basis for structure formation control in deformable sparingly alloyed white cast iron for wear-resistant parts production

This thesis work is dedicated to broadening the scientific basis for structure formation control in deformable sparingly alloyed white cast iron to develop optimal chemical compositions and methods of using white cast iron for strain processing technology applied in existing industrial environment, which is aimed at facilitating production of metallurgical equipment components and machine building equipment components with increased service durability. Chipless shaping allows to significantly improve mechanical properties of white cast iron and provides new opportunities to apply it as either instrumental, or construction material. This work features a summary of how chrome, molybdenum, tungsten, and vanadium influence the structure formation in ledeburite cast iron. Phase transition regularities in alloyed cementite. The influence of carbide transformations on ductility, hardening and softening processes during deformation when applying different straining methods, as well as the influence of annealing following chipless shaping was determined. Production technologies for bar iron and deformable cast iron forgings were developed, tube extrusion and cast iron section rolling broaching were performed, cast iron sheet rolling to 2 mm thickness was probed. Compositions of sparingly alloyed white cast iron subject to chipless shaping with total content of alloying ingredients not exceeding 2-2.5%, content of carbon being 2.7-3.2% were developed. Also annealing cycles and thermal treatment schedules to increase by factor of 2.5-4 wear-resistance of forming rolls made of deformable cast iron and used in cold rolling were developed. This also allows replacing an expensive alloy used for production of distributing rollers with cast iron.