Modern approaches ensuring rational conditions for continuously cast billet formation in a billet CCM mold.

Abstract

The development of technology and technology of continuous steel casting actualizes the improvement of the control system of casting processes and diagnostics of the formation of continuously cast billets. The conditions determining the stability of continuous cast billet forming process in billet CCM mold are considered: the correspondence of liquid steel mass entering the mold and the outgoing billet mass; ensuring the specified intensity and uniformity of billet cooling in the mold sleeve; ensuring a rational level of friction in the crystallizer. It is shown that, on the one hand, heat transfer in the mold is largely determined by the correspondence of the billet shrinkage and the internal profile of the mold, but, on the other hand, it is noted that it is impossible to obtain a universal profile that creates optimal conditions for the formation of billets from all grades of steel with arbitrary temperature-speed parameters. Therefore, the concept of a universal crystallizer assumes that rational conditions of heat removal are achieved due to additional influences. The basics of diagnosing of heat exchange processes in the crystallizer are presented, based on the computational processing of the current ACS signals about the cooling water temperature drop in the crystallizer and its flow rate. It is noted that this system, unfortunately, does not guarantee the detection of local unevenness of the heat removal in the crystallizer and needs to be improved by providing the possibility of assessing the billet faces cooling uniformity. Modern approaches to optimize internal profile of crystallizer sleeves, choice of materials for coating inner surface of sleeves, choice of parameters of mold swinging system and diagnostics of parameters of force interaction between crust of forming billet and mold sleeve are briefly considered on issue of friction rational level establishing. The creation of a “universal” crystallizer with an increased number of control systems and the creation of a system for optimization of casting processes for specific conditions are identified as possible directions for the development of approaches to ensure rational conditions for the formation of continuous cast billets in the crystallizer of a billet caster.