The cast iron bed adopted by this machine has the following characteristics:1. The casting bed is made of gray cast iron, which has high carbon content and is not easy to be deformed by heat. 2. Casting the bed, one body, after aging treatment, its internal stress can almost be ignored, thus high stability can make the accuracy of the machine tool for a long time to maintain. 3. Compared with the ordinary welding bed, the casting bed is much heavier. In theory, the heavier the bed is, the smaller the machine vibration is, and the less the impact on the cutting quality. 4. Casting bed notch sensitivity is lower, because the bed in transportation and processing and other links, there will be an inevitable unexpected gap, cast iron bed due to the material characteristics, there will not be any change due to the gap, so as to further improve the overall stability of the machine. Whether casting or welding, there is a thermal process. In this case, there must be residual stress inside the structure after cooling. Residual stress can make the geometry of the machine in an unstable state, which is obviously not allowed for the machine like a mother machine. In terms of technology, the casting machine body is usually given aging treatment after casting. The welded bed is then subjected to stress relief annealing to eliminate the threat of these residual stresses before being processed into the bed product.
The casting bed has good stability, high cost and long life, causing trouble: wood mold → sand mold → pouring → forming → removing the head → heat treatment → natural aging (at least 3 years, but more than 10 years)→ artificial aging → planing → forceps → high-frequency quenching → grinding → testing.