Large machine parts castings

The large-scale machine tool castings are made of resin sand and lost foam solid casting. The single piece reaches more than 40 tons, and has the characteristics of relatively low melting point, good fluidity and small shrinkage. Large machine tool castings using vanishing models and resin sand casting have the following advantages: 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. In the real casting production, the polystyrene foam molding is applied to 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. Relatively speaking, lost foam casting has great advantages for producing single or small batches of automobile covers, machine tools and other large molds compared with traditional sand molds. It not only saves expensive wood type costs, but also is easy to operate and shorten. The production cycle has improved production efficiency, and has the advantages of high dimensional accuracy, small machining allowance and good surface quality. The high-strength cast iron HT250-300 made of large machine tool castings has strong tensile strength and long service life. It is widely used in the processing of parts such as instrumentation, electronics, light industry, standard parts, bearing industry and auto parts industry, especially suitable for color. metal. The production of large-scale machine tool castings adopts a complete resin sand production line, which is made of resin sand and lost foam casting. The dimensional accuracy is high and uniform, without buckle, the castings are free of flash and burrs; the surface smoothness is close to precision casting, and the internal structure is stable. . Anti-rust treatment of large machine tool castings: Due to the particularity of the manufacturing process of large machine tool castings, the surface of large machine tool castings is prone to rust, which is difficult to handle after rusting. If it is not taken seriously, not only the anti-corrosion ability of the workpiece is poor, but also the decoration is not good. Many enterprises put forward high corrosion resistance requirements for large machine tool castings, and according to the different working conditions of large machine tool castings, it is required to carry out normal temperature blackening, phosphating and other special processing for large machine tool castings (cast iron, cast steel). Anti-rust treatment. The surface anti-rust treatment of large machine tool castings has received more and more attention from people. This is also a problem that we often encounter in machining and equipment maintenance. To solve such problems, we will improve the quality of related enterprise products. Positive role, this is not only the need of market competition, but also the requirements of enterprise development.