Brief introduction of casting process With the advancem […]
Brief introduction of casting process
With the advancement of science and technology and the vigorous development of the foundry industry, different casting methods have different mold preparation contents. Taking the most widely used sand casting as an example, mold preparation includes two major tasks: molding material preparation and molding core making. The various raw materials used in sand casting to form the core, such as foundry sand, sand binder and other auxiliary materials, as well as the sand, core sand, coatings prepared from them, are collectively referred to as modeling materials. The task of modeling materials is to follow the casting According to the requirements of the metal, choose the appropriate raw sand, binder and auxiliary materials, and then mix them into molding sand and core sand with certain properties in a certain proportion. Commonly used sand mixing equipment includes roller type sand mixer, counter-current sand mixer and blade groove sand mixer. The latter is specially designed for mixing chemical self-hardening sand, continuous mixing and fast speed.
Modeling core is carried out on the basis of determining the modeling method and preparing the modeling materials according to the requirements of the casting process. The accuracy of the casting and the economic effect of the entire production process mainly depend on this process. In many modern foundry workshops, sculpting and core making have been mechanized or automated. Commonly used sand molding core making equipment include high, medium and low pressure molding machines, sand blasting machines, boxless injection molding machines, core shooting machines, cold and hot core box machines, etc.
After the casting is taken out from the pouring and cooling mold, there are gates, risers, metal burrs, piping and parting lines. Sand castings still adhere to sand, so they must go through a cleaning process. The equipment for this kind of work includes polishing machine, shot blasting machine, pouring riser cutting machine and so on. The falling sand cleaning of sand castings is a process with poor working conditions. Therefore, when choosing the molding method, try to create convenient conditions for falling sand cleaning. Due to special requirements, some castings have to undergo post-casting treatments, such as heat treatment, shaping, anti-rust treatment, and rough machining.