Development and applications of grey iron castings

With desirable stock material readied, iron foundries use several different processes to produce grey iron castings. Virtually every technique requires the liquification of the grey iron which is then poured into a mold and cooled at precise rates before the completed part is ejected. Aluminum die casting employs reusable dies which contain an impression of the finished product. This method is popular when continuous cycle or fast production is needed. Centrifugal casting is used for cylindrical parts and components and works by rotating the mold at high speeds as the molten metal is introduced. This creates a fine grained outer surface with even dispersion. Pump casting is another commonly used process as it is low cost and easily accomplished. A two part mold cavity is formed using a sandy mixture, the composition of which can be any of four choices which include green sand, skin-dried, dry sand and no bake. The material chosen depends largely upon the accuracy needed and the desired surface finish which is often rough and may require finishing operations. As most mold and casting techniques leave the possibility for burrs and other undesirable artifacts, iron foundries often provide a number of secondary operations in order to provide more finished products. Additionally, processes such as annealing, machining, painting and galvanizing among others may also be had at several metallurgical work shops.

Though often confused with forges, only foundries provide the closed mold operations needed to produce quality grey iron castings for the many industries that employ them. Automotive, agricultural, machinery building, electronics, irrigation, ventilation, architecture, construction and transportation industries all utilize these molded parts in daily operations as they provide both strength and durability. As a building and construction component, grey iron castings provide protection against fires as they are non-flammable and thus preferred over wooden support structures. The graphite content of the parts also provides reliable and efficient energy dissipation making the parts suitable for applications in which the dampening of mechanical vibrations is required or desired such as crankshafts and engine blocks. Additional cast iron gear components commonly used include pipes, cases, dies and even decorative embellishments as the material is easily machined with accuracy and precision.

alloy castings: http://www.ftm-china.com/product/alloy-steel-castings.html