Modern slide valve systems for steel casting

Abstract

The current situation in Russia regarding steel casting using slide valves in Russia is discussed and its main drawbacks are identified. Promising slide valves with elastic elements have been developed by the Shiber JSC (a domestic manufacturer). The advantages of the state-of-the-art valves include a "book-like" opening system, presence of spring elements, durability, and convenience in servicing. Slide valves should be compatible with the drive mechanism (hydraulic stations are recommended for this purpose) and a set of state-of-the-art refractories.The process of slide teeming in Russia is still at the level of 1980s and the majority of large metallurgical companies are not interested in its advance for the following reasons:-main investments are made into upgrading the rolling production; in reconstruction of steel-melting divisions investments are made in expensive machinery, which provides increased production volume or improved quality of metal (furnace-ladles plants, vacuum machines, etc.) -large companies have their own shops for producing old-type slide gates and their closing may cause social tension;-single-use refractories for slide units made in Russia are cheaper than imported analogs (2 -3 times). The consumers of refractories agree to buy obsolete refractory products due to their low price.However, some reasons encourage consumers to upgrade this type of metal casting. To ensure the required quality of metal, especial product for export, producers introduce contemporary technologies, in particular, extra-furnace treatment methods. Some metallurgical companies producing steel in open-hearth or small electric arc furnaces actively implement aggregates for complex treatment of steel (ACTS) and vacuum machines and thus significantly improve the quality of metal produced. An ACTS uses expensive main lining. Its efficient use requires prompt replacement of refractories making part of the slide unit. The replacement of refractories used to take 2 -3 h, whereas now it has to be carried out in 10 -15 min.One of the main factors in this line of research is an integrated approach to the development and production of slide systems. The fact that Russia substantially lags behind the advanced countries in this area is related to a lack of systematic approach. Manufacturers of slide valves, producers of refractories, as well as metallurgists consuming the former products tried to impose their own frequently unjustified requirements on the other participants of the process. The problem of steel teeming from ladles with slide valves was solved disregarding the latest world experience. A current slide system has the following components: a slide valve, a drive, and refractory elements of the teeming unit. SLIDE VALVE DESIGNEach component of a slide system has is own function and a particular cost. The cost of a contemporary slide gate and a drive withstanding over 2000 heats is 20 -25 rubles per heat (0.002% of the steel production cost). These expenses are one-time expenses and require substantial funds. The repa...