Technology of roll production for cold rolling of strip using electroslag remelting method

The article is concerned with the description of the manufacture of rolls for cold rolling of strip using electroslag remelting process and decommissioned rolls. It also describes modes of initial and final thermal treatment of work rolls providing the necessary hardness of the roll barrel and depth of the hardened layer. The article offers the scheme and experimental results aimed at electroslag remelting of decommissioned rolls in plant conditions at an industrial electroslag installation. The research group found the relationship between the slag bath height variation and the descending rate of the decommissioned roll acting as a consumable electrode into the molten slag bath in electroslag remelting process. The mold of new design for electroslag remelting was offered to provide higher surface quality of the cast ingot and to improve the quality of roll neck metal. The mode of enhanced roll production was developed to obtain a uniform fine-grain pearlite structure, which is necessary for the final thermal treatment. The offered mathematical models of the final thermal treatment make it possible to determine the optimal modes of roll thermal treatment, which will provide higher hardness of the roll face and the necessary structure of the hardened layer as well as its phase composition. The offered mathematical model of thermal cycling and roll heating for hardening allowed the authors to give theoretical justification of rational thermal treatment conditions, which contribute to formation of an active layer of the predetermined depth and hardness in the roll without causing its breakdown.