Foseco’s foundry filters are designed to provide the casting producer with high levels of inclusion removal and flow control as the metal enters the mould.
STELEX filters for steel and high temperature alloy filtration smooth metal flow and mould fill when used in a conventional gating system. They also remove non-metallic inclusions such as furnace and ladle refractory materials and slag, moulding sand, products of de-oxidation, and re-oxidation. Filtration provides improved casting quality, productivity, and profitability. The casting producer benefits from reduced re-work costs associated with welding and cleaning, reduced casting returns, and often increased casting yield. In addition the casting exhibits improved machinability facilitating improved machine tool life.
Filtration effectiveness is largely dependent on the correct application and positioning of the filter. Foseco Service Engineers are able to provide technical application support for the incorporation of filters and design of gating systems.
STELEX ZR Zirconia Filters
STELEX ZR filters are based on zirconia which generates a highly stable refractory material offering a unique combination of thermal shock resistance, resistance to chemical attack, hot strength and creep resistance.
STELEX ZR ULTRA Zirconia Filters
STELEX ZR ULTRA filters enable even higher filtration efficiency to be achieved through the use of finer pore filters. An integral ceramic frame around the filter enhances the strength which enables improved performance consistency.
STELEX PrO Carbon Alumina Filters
STELEX PrO carbon filters have a low thermal mass and are ideally suited for application to carbon, low alloy and manganese steel casting production.
STELEX PrO filters provide optimal priming characteristics and are therefore suited to applications where metal chill by the filter are a concern. Because STELEX PrO filters effectively prime at lower temperatures than traditional zirconia based filters, the application of filters to steel castings is expanding.
HOLLOTEX Running and Gating System Components
Centrifugal filter units
HOLLOTEX CFU products are highly engineered filtration devices used exclusively in the production of large ferrous castings. The device comprises of a HOLLOTEX Refractory Centrifuge System and STELEX Ceramic Foam Filters.
The HOLLOTEX refractory centrifuge system separates inclusions from the molten metal before it reaches the filters. The integral STELEX ZR filters remove remaining contaminants from liquid metal and reduce turbulence as the mould cavity fills.
HOLLOTEX Shroud provides a reliable method of shrouding the metal stream as it exits the bottom pour ladle eliminating air entrainment in the sprue, and the subsequent formation of re-oxidation inclusions. The molten metal is therefore cleaner, allowing a higher level of filtration efficiency and turbulence reduction in the production of large steel castings.