We are not unfamiliar with castings, and casting applications have a long history. In ancient times, people used castings to make coin sacrifices, weapons, tools and some household appliances. However, in modern times, castings are mainly used as rough parts of machine parts or directly as machine parts. The proportion of castings in mechanical products has begun to increase, the amount of use has also increased year by year, and the shape and variety of castings are also constantly changing. Castings have gradually become an indispensable part of our daily life. The use of castings can be seen in various places such as various door handles, door locks, and small water pipes.
The casting has excellent mechanical and physical properties. It can have various comprehensive properties of strength, hardness, and toughness. It can also have one or more special properties, such as wear resistance, high temperature and low temperature resistance, corrosion resistance, etc. .
The castings have a wide range of weights and sizes. The lightest weight is only a few grams, the heaviest can reach 400 tons, the thinnest wall thickness is only 0.5 mm, and the thickest can exceed 1 meter. Can meet the requirements of different industrial sectors.
Compare the differences between castings and stainless steel forgings:
1. Castings have good abrasion resistance and shock absorption, because graphite in cast iron is good for lubrication and oil storage, so it has good abrasion resistance. Similarly, gray graphite cast iron has better shock absorption than steel because of graphite.
2. The casting has good process performance. Because of the high carbon content of the gray cast iron, which is close to the eutectic composition, the melting point is relatively low, the fluidity is good, and the shrinkage rate is small. Therefore, it is suitable for casting with complex or thin-walled castings. It is easy to form chip breaking during cutting, so the machinability of gray cast iron is better than that of steel.
3. After forging, stainless steel can improve its microstructure and mechanical properties. Due to the deformation and recrystallization of stainless steel after hot working deformation of the forging method, the original coarse dendrites and columnar grains become equiaxed recrystallized structures with finer grains and uniform size, which causes the original segregation, The compaction and welding of looseness, pores, and slag inclusions make the structure more compact, which improves the plasticity and mechanical properties of the metal.
4. The mechanical properties of castings are lower than those of forgings of the same material. However, the forging process can ensure the continuity of the metal fiber structure, make the fiber structure of the forging consistent with the shape of the forging, and ensure that the part has good mechanical properties and long service life. Precision die forging, cold extrusion, warm extrusion and other processes are used. The forgings produced are unmatched by castings.
Both castings and stainless steel forgings are an indispensable part of mechanical production. In mechanical production, according to the different product properties, choose the corresponding castings or forgings. Only by fully exerting the role of castings or forgings can there be perfect mechanical products.