Combined method of foundry and thermal processes of manufacturing castings from iron-carbon alloys

Abstract

With the help of innovations at an industrial enterprise, it is possible to increase labor efficiency and reduce the resource intensity of production. The relevance of the development of the technology of metal casting in sand molds, as the most common casting process, is justified by the fact that up to 80 % of the tonnage of castings is produced in such molds, including special types of casting in molds from sand materials. 60-70 % of the equipment capacities, areas, and personnel of foundry shops are attributed to molding processes, including mixing and rod production. Pollution "due to the mold" can reach up to 80%. A significant potential for the development of foundry mold technology is the improvement of the processes of casting metal into molds made of loose sand without a binding component, in particular, according to the Lost Foam Casting Process (LFC). The authors present the concept of improving the processes of casting metal into molds made of loose sand by the method of dual application of molding materials and give examples of such application. The use of loose molding sand for rapid cooling of the casting, including heat treatment, is able to strengthen its metal and reduce the duration of cooling of the casting in the mold, which leads to an increase in the productivity of foundries without increasing the number of furnace equipment and loose mold filler. The applied method of isothermal hardening (austempering) from the hot state of castings from iron-carbon alloys excludes heating with exposure for austenization of castings, which reduces the cost, time and energy consumption of obtaining products with a strengthened bainite structure, which, in fact, corresponds to the concept of realizing internal reserves as a foundry sand mold, and cast metal. Some foundry enterprises of the Vinnytsia region also use LFC or have concluded contracts, planning to reconstruct their shops for this ecological and economically beneficial foundry technology.