研究了灰铸铁局部激冷后的组织及硬度变化特征，通过试验确定了使用冷铁的工艺参数。生产试验结果表明，机床导轨处使用冷铁激冷，能有效地提高导轨面的铸态硬度，且导轨面硬度均匀性和床身断面均匀性提高。 The characteristics of the microstructure and hardness of the gray cast iron after partial chilling were studied. The process parameters of the cold iron were determined through experiments. Production test results show that chilled iron chill is used at the guide of the machine tool, which can effectively improve the as-cast hardness of the guide rail surface and improve the hardness uniformity of the guide rail surface and the homogeneity of the bed section.