Ivanova L. Theoretical bases and practical methods of receipt of the poured forming rolls from complex modifying cast irons

Dissertation is devoted to the development of theoretical bases of a choice of rare-earth metals for the modifying of white, halved and grey rolling cast irons and application of complex modifiers on thier basis, the establishment of laws of formation of structure and properties of meterial of forming rolls with chill and unexpressed chill from cast irons with spheroidal and vermicular graphite and mastering of progressive tochnologies of modifying of cast irons of the forming rolls and their hot treatment. Scientifically grounded theoretical and experimentally confirmed results have been got. The aggregate of their results has allowed at the level of inventions to develop high-efficiency technologies of modufying cast irons by the complex modifiers of optimum compositions for forming rolls with chill and unexpressed chill, mechanical and operational properties of which conciderably excel similar properties of the rolls made on serial technologies. The application of off-cuts of the special productions(slugs, containing rare-earth metals, niobium, zircinium, and also alloys, containing niobium, titan, copper, tin) as the alloying elements have been offered and experimental grounded. These off-cutc and mixtures containing modifying and alloying components for casting of cast iron forming rolls have been used. Treatment of fusions by the off-cuts and mixtures allows to shorten exoence of alloying elements, to improve mechanical and operational properties of rolls, to utilizethe off-cuts which have not use before. Optimum hot treatments including of hot castings from the complex modified cast irons with spheroidal or vermicular graphite heve been determined.