Machine tool castings Casting standards and advantages of large machine tool castings - casting technology
First, the bed standard: GB9439-88
Second, the characteristics of large machine tool casting bed:
(1) Good wear resistance and shock absorption, because the graphite in cast iron is conducive to lubrication and oil storage, so good wear resistance. Also due to the existence of graphite, the shock absorption of gray cast iron is better than that of steel.
(2) Good process performance, due to the high carbon content of gray cast iron, close to the eutectic composition, so the melting point is relatively low, good fluidity, small shrinkage, so suitable for casting structure complex or thin-walled castings. In addition, because graphite makes it easy to form chip breaking during cutting, the machinability of gray cast iron is better than that of steel.
Third, the relationship between hardness and tensile strength: there is a certain corresponding relationship between the hardness and tensile strength of gray cast iron, and its empirical relationship is:
1, when O≥196N/mm㎡ HB=RH(fly 00+0 4380b) (B1)
2, when 0≥796N/mm㎡ HB=RH (44+O 7240b) (B2) in the relative hardness (RH) value is mainly determined by the raw materials, melting process, treatment process and cooling speed of the casting.
Four, the use of resin sand casting machine tool castings bed castings advantages:
1, resin sand stiffness, high strength of the initial casting of the sand, which has the conditions to use the graphitization expansion of cast iron solidification process, effectively eliminate shrinkage holes, shrinkage defects, to achieve less riser casting, no riser casting gray cast iron, ductile cast iron;
2. In the solid casting production, polystyrene foam pattern is used and Furosol resin self-hardening sand modeling is applied. When the metal liquid is poured into the mold, the foam mold quickly vaporizes under the action of high temperature metal liquid, burns and disappears, the metal liquid replaces the position occupied by the original foam, and cools and solidifies into a solid casting with the same shape as the mold;
3, Relatively speaking, the lost mold casting for the production of single or small batch of automotive covering parts, machine tool bed and other large molds than the traditional sand mold has a great advantage, it not only saves the expensive wood type cost, but also easy to operate, shorten the production cycle, improve the production efficiency, with high dimensional accuracy, small processing allowance, good surface quality and other advantages.
Changshu Hongqiao Cast Steel Co., Ltd. is located in the Yangtze River delta, at the foot of Yushan, Changshu City, next to 204 National Highway, Sujia-Hangzhou Highway, along the river highway are within 5 kilometers. Changshu City international garden health city, Yushan National Forest Park, Shajiabang reed, Shanghu and other scenic spots, simple folk customs, rich historical heritage, beautiful environment, transportation is very convenient.
Founded in March 2003, the company is a private joint-stock enterprise. The company now covers an area of 25,000 square meters, production workshops of 15,000 square meters, offices, dormitories of 2,000 square meters, more than 100 employees.
The company mainly produces various specifications of carbon steel, high, medium and low alloy steel, stainless steel, heat-resistant steel, high manganese steel, high chromium cast iron. For petroleum, chemical industry, metallurgy, mining machinery, coal mining machinery, wind power, nuclear power, Marine and other industries to provide high-quality steel casting, and export abroad.