要保证机床精度的长期稳定性,除去设计的结构刚性外,最关键的是取决于灰铸铁铸件的机械性能。而灰铸铁的机械性能又取决于它的基体组织和石墨的形状、大小、分布。化学成分、冷却速度、孕育处理、炉料和铁水过热温度等诸因素直接影响着铸铁的石墨化和基体组织,其中冷却速度的大小是影响铸铁结晶过程中基体组织和晶粒大小的重要因素之一。冷却速度之所以能影响铸铁组织,是因为它改变了过冷度的大小。冷却 To ensure the long-term stability of machine tool accuracy, except for the structural rigidity of the design, the key is to depend on the mechanical properties of gray iron castings. The mechanical properties of gray cast iron in turn depends on its matrix and graphite shape, size, distribution. Chemical composition, cooling rate, inoculation, charge and hot metal overheating temperature and other factors directly affect the graphitization and matrix microstructure of cast iron. The cooling rate is one of the important factors affecting the microstructure and grain size of cast iron during crystallization . The reason why the cooling rate affects the cast iron structure is that it changes the degree of undercooling. cool down