SAND CASTING EQUIPMENT.

1. There are many factors that affect the quality of castings. The xinyuanzhu Group summarizes the following aspects in the process of reproducing and casting:
1.1 Design manufacturability of castings. When designing, in addition to determining the geometry and size of the casting according to the working conditions and the properties of the metal material, the rationality of the design must also be considered from the perspective of the casting alloy and casting process characteristics, that is, the obvious size effect and solidification and shrinkage. , Stress and other problems to avoid or reduce the occurrence of defects such as component segregation, deformation, and cracking of the casting.
1.2 There is a reasonable casting process. That is, according to the casting structure, weight and size, casting alloy characteristics and production conditions, select the appropriate parting surface and shape, core making method, and reasonably set the casting rib, cold iron, riser and gating system. To ensure high-quality castings.
1.3 The quality of raw materials for casting. The quality of metal charge, refractory materials, fuels, fluxes, modifiers and foundry sand, sand binders, coatings and other materials are substandard, which will cause pores, pinholes, slag inclusions, sand sticking and other defects in the castings, which will affect the appearance quality of the castings and internal quality, if serious, the casting will be scrapped.
1.4 Process operation, it is necessary to formulate reasonable process operation procedures, improve the technical level of workers, so that the process regulations can be implemented correctly.

2. The quality of castings has a great influence on the performance of mechanical products, so the quality of castings is very important. Xinyuanzhu Group will share five common metal casting problems and countermeasures with casting colleagues
2.1 Pinholes in metal castings
Measures to prevent pinholes: It is strictly forbidden to use contaminated cast aluminum alloy materials, materials stained with organic compounds and severely oxidized and corroded; control the smelting process, strengthen degassing and refining; control the thickness of metal coatings, too thick will easily produce pinholes ; Mold temperature should not be too high, adopt chilling measures for thick wall parts of castings, such as copper inlay or watering, etc.; when using sand molds, strictly control moisture and try to use dry cores.
2.2 Porosity often occurs in metal castings
Measures to prevent pores: modify the unreasonable pouring and riser system to make the liquid flow stable and avoid the entrapment of gas; the mold and core should be preheated, and the paint must be applied afterwards, and the mold must be dried thoroughly before use; design the mold Adequate exhaust measures should be considered with the core.
2.3 Oxidation and slag inclusion often occur in metal castings
Measures to prevent oxidation and slag inclusion: strictly control the smelting process, fast smelting, reduce oxidation, and thoroughly remove slag; Al-Mg alloy must be smelted under a covering agent; furnaces and tools must be clean, free of oxides, and preheated, paint After coating, it should be dried and used; the designed pouring system must have stable flow, buffering, and slag-skimming capabilities; the inclined pouring system should be used to stabilize the liquid flow without secondary oxidation; the selected coating must have strong adhesion and no Flaking occurs and enters the casting to form slag inclusions.
2.4 Hot cracking often occurs in metal castings
Measures to prevent thermal cracking: In the actual pouring system, local overheating should be avoided to reduce internal stress; the inclination of the mold and core must be above 2°, and the pouring riser can be core-pulled to open the mold once it has solidified, and sand cores can be used if necessary Replace the metal core; control the thickness of the coating to make the cooling rate of each part of the casting consistent; select the appropriate mold temperature according to the thickness of the casting; refine the alloy structure to improve the hot cracking ability; improve the casting structure, eliminate sharp corners and wall thickness mutations, and reduce Hot cracking tendency.
2.5 Metal castings often appear loose
Measures to prevent porosity: reasonable riser settings to ensure solidification and feeding capacity; appropriately lower the working temperature of the metal mold; control the thickness of the coating and reduce the thickness of the thick wall; adjust the cooling rate of each part of the metal mold to make The thick wall of the casting has a greater chilling capacity; appropriately reduce the metal pouring temperature.

Xinyuanzhu Group specializes in the production of Ductile iron castings, Pig iron gray iron casting, Steel casting, Brass Casting, Malleable Iron Casting, and undertakes batch casting processing of castings. Welcome guests to cooperate with pictures or samples.