Zhizhkina N. Scientific and technological base of casting of massive bimetal ingots for rolling mills

The dissertation is devoted to theoretical researches of centrifugal casting of sheeting rolls with the required level of properties and development of their production technology. The influence of it parameters at massive rolls formation is substantiated by theoretical estimations. As a result pressure change along rotated form, non-metallic inclusions quantity in working layer and it non- uniformity decreased 2 times, 4 times and 3.6 times respectively. The strength condition of working layer shell that solidifies at the surface of mold is reserved. The excess of its value there are observed hot cracks in roll barrel. The evaluation method of influence rotated solidification cast iron at it refining of non-metallic inclusions and it structure is proposed. Structure shredding, increasing of carbides' quantity in structure and hardness level by 10 % are estimated. It is established that centrifugal machine stability increase uniformity of rolls' working layer by 35 %. Composition of cracks' resisting cast iron is developed for working layer of rolls. This cast iron is characterized of uniform structure and increasing level of hardness (by 10 %) and bending strength (by 3 %). It is proposed metal treatment of compacted reagent and gas-like nitrogen in ladle. As a result operating time increases at 20 %. The design of roll with special transition zone is proposed. It estimate welding of it layers and decreased chromium quantity at core 6 times. It is proposed cooper alloying of core for increasing of it properties. The total economic effect of dissertation introduction at production sphere of rental equipment came to 5,22815million UAH.