耐低温冲击球墨铸铁的工艺控制

为生产耐低温冲击球墨铸铁件，制定了不同球化及孕育处理工艺的组合方案，对浇注的试样进行了拉伸和低温冲击性能试验，并观察了显微组织，分析了不同预处理工艺和多次孕育工艺对球墨铸铁石墨形态和力学性能的影响。结果表明：采用稀土球化剂、包内预处理及多次孕育的组合工艺，能显著改善石墨球径的均匀性及石墨球分布的均匀性，保证球墨铸铁低温冲击性能的稳定。

Process Control of Low-Temperature Impact Resistant Ductile Iron

To produce low-temperature impact resistant ductile iron castings, the combining schemes with different spheroidizing and inoculation process were established. The tensile and low-temperature impact property for samples were tested and their microstructure was observed. The effects of different pre-treatment and multi-inoculation process on the graphite morphology and mechanical property of ductile iron were analyzed. The results show that the integrated process with RE nodulizer, ladle pre- treatment and multi-inoculation can be used to improve the uniformity of the diameter and distribution for graphite module and stabilize the low-temperature impact property of ductile iron.