Resin sand casting machine bed casting advantages: 1, resin sand stiffness, initial sand casting, high strength, which conditional use graphite cast iron during solidification of the expansion, effectively eliminate shrinkage, shrinkage defects, to achieve gray cast iron, Ductile Iron Castings less riser, no riser casting .2, solid casting used in the production of polystyrene foam appearance, taste furans application of self-hardening resin sand molding. When the liquid metal poured into the mold, the foam looks like in the endless liquid metal under high rapid gasification, liquid metal to replace the original position occupied by the plastic, cooling and solidification into the same shape and look like real type casting .3, relatively speaking, lost foam casting for the production of single or small quantities automobile parts, machine tools and other large bed of the traditional sand mold gown has a great advantage, it not only eliminates the cost of expensive wood type, and easy to operate, reducing the production cycle and improve production efficiency, with high dimensional accuracy, machining margin is small, and good surface quality advantages, the advantages of good surface quality. large-scale machine tool gray casting process: With the rapid development of China's machinery manufacturing industry, large-scale machine tool increasingly wide range of applications. In large machine tools manufacturing process, the production of large castings is particularly important. Large castings as a major component of the machine, widely used in various milling machine range, up trucks and other large machine tools. Production of large castings in various aspects of process design from the deterministic effect on the production process, quality of casting have a significant impact. Casting unit value based on large, risky, a huge loss but there waste. Therefore, the correct process to develop a complete program is even more important. In the process design should be a trace of informality, excellence, to ensure the quality of castings. Large cast iron is characterized by: 1. Weight, generally about 15-60 tons. 2 outlines the specific performance of large dimensions: length long, usually 5-15 m; height is high, typically 0.7-2 meters. 3 shapes, complex structure, more sand core. 4 uneven wall thickness. Slide, rails, countertops and other important parts of the wall and do not allow any large defects; but also to ensure its uniform composition, mechanical properties and stability. Large cast iron is generally single, small batch production. Grades to gray cast iron main, as well as some cast iron pieces. The main products are column, table, bed, beams and so on. Here I talk about large-scale example of a beam of gray cast iron craft design process.