Briefly describe what is the precision casting process
Precision casting production and processing can be divided into gravity casting and working pressure casting according to the casting process of molten metal. Gravity casting refers to the process of introducing molten metal into the mold under the effect of the earth's gravity, also known as casting. Theoretical gravity casting includes sand mold casting, metal mold casting, investment casting, lost foam casting, mud mold casting, etc.; the narrow meaning of gravity casting specifically refers to metal mold casting.
Precision casting is also called investment casting. This processing technology avoids or does not carry out drilling at all during the whole casting process. It is a casting processing technology with little or no drilling, and it is an excellent production technology in the casting field. It has a wide range of applications. It is not only suitable for casting of various types and various aluminum alloys, but also the precision and process performance of the castings produced are higher than other casting methods.
RefinedThe dense casting field is different from the traditional casting field because of the high market competitiveness of stainless steel precision casting. According to relevant statistical analysis (2013Annual data information), among European countries’ aerospace machinery and equipment and excellent automobile engines, the market competitiveness of precision casting originals is close to accounting for the total value-added70%, But the market share in our country is not enough35%. At the present stage in our country, although our country has a large casting volume, the use value of casting is still at an upstream level, and it is not yet possible to achieve a high level.
Because the temperature of the shell is about800Above ℃, the temperature of pouring molten steel is about1600Above ℃, the temperature that touches the surface of the carbon steel precision casting is higher, and the metal is not easy to condense in a short time, especially for thick-walled pipes. At this time, the oxygen in the air easily undergoes the reaction between the shell and the metal surface to form metal oxides. And converge with the impurities in the molten steel to form black spots. Therefore, when the large objects are poured, they will participate in the wood chips (or charcoal) in the insulation. It is a key countermeasure to prevent black spots.