There are many classification methods for Castings in Dalian: according to the metal materials used, castings are divided into steel castings, iron castings, copper castings, aluminum castings, magnesium castings, zinc castings and titanium castings. Each casting can be further divided into different types according to its chemical composition or metallographic structure. For example, iron castings can be divided into gray castings, ductile iron castings, vermicular iron castings, forged castings and alloy castings. According to different mold forming methods, castings can be divided into ordinary sand castings, metal castings, die castings, centrifugal castings, continuous castings, investment castings, ceramic castings, electroslag remelting castings, bimetal castings, etc. Among them, ordinary sand castings are widely used, accounting for about 80% of the total output of castings. However, aluminum, magnesium, zinc and other non-ferrous metal castings are mostly die castings.
Precision casting is different from other traditional industries. It is a new casting process, which is still in the development stage in China. Stainless steel is famous for its high corrosion resistance, high temperature resistance, heat resistance, acid resistance and oxidation resistance. Precision castings have high dimensional accuracy and very clean product surface. Stainless steel precision castings reduce the processing workload to a certain extent, and have good advantages.
General technical requirements for Dalian castings:
1. Material requirements. It mainly includes hardness, tensile strength, elongation and impact toughness.
2. Dimensional accuracy and form and position accuracy. For different castings, different dimensional and geometric tolerance standards and different tolerance classes are used.
3. According to the use requirements, the acceptance requirements for other defects of castings shall be specified. Such as air hole, sand hole, shrinkage cavity, shrinkage porosity, slag inclusion, sand inclusion, crack, etc.
Because the technological characteristics and mechanical properties of part materials roughly determine the type of blank, the part materials of cast iron castings still play a key role in the selection of blank. For example, cast iron parts are used for casting blank; Bars are often used in the case of simple state and low requirements for mechanical properties. For important steel parts, forgings should be selected in order to obtain good mechanical properties. When the shape is complex and the mechanical property requirements are low, steel castings shall be used; Non ferrous metal parts are commonly used as profiles or billets. Therefore, the choice of blank is very important for precision casting.
Cast iron castings generally need cutting fluid, so which cutting fluid should be selected? What should be paid attention to in other machining? Cast iron antirust cutting fluid contains additives, which has excellent lubrication, antirust, hard water resistance, antibacterial and long service life. It is suitable for all kinds of aluminum, copper, stainless steel, alloy steel, cast iron, high carbon steel and other materials.
