Sand casting is preferred for machine bed castings. The main reason is that sand casting has lower cost, simple production process and shorter production cycle than other casting methods. When the wet type does not meet the requirements, consider using a clay sand table dry sand type, dry sand type or other sand type. The machine bed castings are manufactured according to the national standard GB9439-88. Resin sand type has good rigidity and high sand strength at the initial stage of casting. It has the condition to utilize the graphitization expansion of the solidification process of cast iron, effectively eliminate the shrinkage and shrinkage defects, and realize the less riser and no riser casting of gray cast iron and ductile iron.
Bed castings can also be called large castings.
Machine bed casting
First, the characteristics of the machine bed
(1) Good wear resistance and shock absorption. Since graphite in cast iron is beneficial for lubrication and oil storage, the wear resistance is good. Also, the shock absorption due to the presence of graphite is superior to steel.
(2) Good process performance. Because gray cast iron has a high carbon content and is close to the eutectic composition, the melting point is relatively low, the fluidity is good, and the shrinkage rate is small, so it is suitable for casting complex or thin-walled castings. In addition, since graphite is easy to form chip breaking during cutting, the machinability of gray cast iron is superior to that of steel.
Second, the relationship between hardness and tensile strength: there is a certain correspondence between the hardness and tensile strength of gray cast iron, and its empirical relationship is:
1. When O≥196N/mmm2
HB=RH (fly 00+0 4380b) (B1)
2. When 0≥796N/mmm2
HB=RH (44+O 7240b) (B2)
The relative hardness (RH) value in the formula is mainly determined by the raw material, the melting process, the treatment process, and the cooling rate of the casting.
Third, the advantages of using resin sand casting machine tool bed castings
1 Resin sand type has good rigidity and high sand strength at the initial stage of casting. It has the condition to utilize the graphitization expansion of the solidification process of cast iron, effectively eliminate the shrinkage and shrinkage defects, and realize the less riser and no riser casting of gray cast iron and ductile iron castings. .
2 In the real casting production, the polystyrene foam molding is used to apply the furose resin self-hardening sand molding. When the molten metal is poured into the mold, the foam plastic form is rapidly vaporized under the action of the high-temperature molten metal, and burns and disappears. The molten metal replaces the position occupied by the original foam, and is solidified into a solid casting having the same shape as the shape.
3 Relatively speaking, lost foam casting has great advantages for producing single-piece or small-volume automobile covers, large-sized molds such as machine bed, and traditional sand molds. It not only saves expensive wood type costs, but also is easy to operate. It shortens the production cycle, improves production efficiency, and has the advantages of high dimensional accuracy, small machining allowance and good surface quality.
Machine tool casting
Why choose us:
The three major system integration certification enterprises, Hudong Foundry passed the ISO9001 quality management system, CE certification, China Foundry Association members, Jiangsu AAA-level contract and keeping promises units.
Excellent manufacturing equipment such as medium frequency induction furnace, large natural gas heat treatment furnace and large-scale spray shot blasting machine have won the Chinese casting field.
The existing imported direct reading spectrometer, tensile testing machine, ultrasonic flaw detector and other advanced testing equipment, the implementation of strict inspection, size and appearance inspection of the factory products.
Open casting design consultation, product quality feedback and quick access, promise product warranty replacement and return, and provide life-long product defect repair service.
Casting cooperation consultation telephone: +86-13761616568