The most fundamental focus of the solution to repair the casting defection in castings is “heat balance.” The method is:
(1) In the thick and hot joints formed by the machine tool casting structure, rapid solidification is carried out, artificially causing the basic balance of the temperature field throughout the casting of the machine tool. The internal and external cold iron is used, and the zircon sand, chromite ore or special coating with large heat storage is used locally.
(2) Reasonable process design. The inner runner is located at the opposite side of the machine tool casting, and is scattered and scattered for several hours. The metal liquid that first enters the thick wall is firstly solidified, and the thin wall is solidified afterwards, so that the equilibrium solidification is basically achieved everywhere. For machine tool castings with uniform wall thickness, multiple ingates and vents are used. There are many internal runners, scattered and evenly distributed to balance the overall heat. The venting holes are fine and numerous, that is, the exhaust gas is smooth and heat-dissipating.
(3) Change the position of the gate
(4) The use of modeling materials with large heat storage is extremely important for the production of anti-wear products with lost foam! The chromite ore replaces other sands such as quartz sand, which have a small heat storage capacity, and will achieve good results.
(5) Low temperature fast burning, open casting system. Make the molten metal fill the mold quickly, smoothly and evenly. This should be tailored to the requirements.
(6) The machine tool of ductile iron has high strength, surface hardness of ≧90, and the rigidity of the sand box is large, which is beneficial for eliminating shrinkage.
(7) When a riser is needed, when the first move is hot, and leave the hot section. If the riser is placed on a hot section, the size of the riser will be increased to form a “hot heating”. If you don’t get it, it will not only shrink and shrink, but also produce concentrated shrinkage holes, which will reduce the process yield.
(8) Both the inclined placement and alloying of the mold benefit. Eliminating shrinkage defects in machine tool castings is a complex process of understanding and implementation. Based on the principle of “heat balance”, we should make a scientific analysis of the body castings, formulate a reasonable technological plan, and select suitable modeling materials, tooling and correct operation and standardization. Then the shrinkage defects of any machine tool casting can be solved.
Alloy Castings,Centrifugal Castings,Open Closed Die Casting,Zinc Die Castings,Heat Treated Castings,Machined Castings Specification of Alloy Castings: Inspection of work-in-progress Finished product inspection Random warehouse inspections All of our operations are strictly compliant with ISO 9001: 2008 guidelines Aluminum Sand Casting and sand casting process is always used for heavy part with big wall thickness and very […]