Castings mainly focus on the wall thickness, shrinkage rate, and other aspects of the castings. These two are directly proportional, which means that if the wall thickness of the casting is large, the shrinkage rate will also be high, and vice versa. During the storage process, the mold will further tighten, usually at 10%. But after 12 hours of storage, the size will not change at all. For heavy castings produced in small batches, manual molding is still an important method. Manual molding can adapt to various complex requirements and is relatively flexible, without requiring many process equipment.

For heavy castings produced in small batches, manual molding is still an important method. Manual molding can adapt to various complex requirements and is relatively flexible, without requiring many process equipment. It can be applied to water glass sand molds, VRH water glass sand molds, organic ester water glass self hardening sand molds, clay dry molds, resin self hardening sand molds, and cement sand molds; For heavy castings produced in single piece production, the pit molding method has low cost and fast production. The carbon in is present in the form of flake graphite, and its fracture surface is gray, commonly known as gray iron.
During the cooling and solidification process of castings, due to the liquid shrinkage and solidification shrinkage of the alloy, holes often appear at the solidification site of the castings. Large and relatively concentrated pores are called shrinkage pores; Small and dispersed pores are called shrinkage pores. The shape of shrinkage pores is irregular, with a rough surface and well-developed dendrite tips visible, which can be clearly distinguished from pores. Stainless steel precision casting flat ingots have a high tendency for hot cracking, and the temperature of stainless steel precision casting is correspondingly lower. Generally, 680-735 * C stainless steel parts are cast.
The products obtained by investment casting are precise and complex, close to the shape of the parts, and can be directly used without or with little processing. It is an advanced process of near net formation and an excellent process technology in the casting industry, with a wide range of applications. It is not only suitable for casting various types and alloys, but also produces castings with higher dimensional accuracy and surface quality than other casting methods, and even complex, high-temperature resistant, and difficult to machine castings that are difficult to cast by other casting methods. It can be cast using investment precision casting. Foam epc has the function of buffering liquid metal filling and cooling during the pouring process, and it can also reduce the erosion of liquid metal.
When the liquid metal replaces the foam lost foam pattern and fills the mold cavity, the dry sand is mainly supported by the coating. When the coating strength or fire resistance is not enough, the local mold will collapse, especially above the large internal runner. Lost foam casting is suitable for complex casting production due to its lack of parting and stripping, as well as the need for a core. For castings that are difficult to separate, difficult to lift, difficult to lower the core, or have a particularly large number of cores, such as cylinder bodies, intake and exhaust pipes, propellers, impellers, fire hydrants, and box components, the advantages and economy of production are more obvious when using lost foam casting.
The above is the relevant content introduced by casting and processing manufacturers, hoping to be helpful to everyone.