铸钢件常因铸造工艺不适宜,特别是大型铸件易出现气孔、夹杂、偏析等缺陷,为避免这种铸造缺陷而造成的开裂,生产中对热处理工艺提出了比较高的要求。1.退火或正火与锻件及轧材相比,铸件有稳定的结晶组织,重结晶温度较高。大型铸钢件因晶粒粗大、魏氏组织及偏析严重,其退火、正火 Casting often due to casting process is not appropriate, especially large castings prone to porosity, inclusions, segregation and other defects, in order to avoid this casting defects caused by cracking, the production of heat treatment process put forward relatively high requirements. 1. Annealing or normalizing and forging and rolling compared to the casting has a stable crystalline structure, recrystallization temperature is higher. Large castings due to coarse grains, Wei’s organization and segregation serious, its annealing, normalizing