目前,在球墨铸铁的热处理中,正火是最常用的工艺之一。由于铸铁件在空气介质(即氧化性气氛)中加热,其表面与氧发生反应,生成氧化层。根据生产实践,我们认为,从球铁件表面氧化层的颜色和形态可以大致判断出其正火加热温度。两者的关系如下: 1.正火温度为800～880℃时,氧化皮的颜色为红综色。随着加热温度的升高,颜色由浅变深;随保温时间的延长,氧化皮由薄膜状变成绒毛状。 At present, normalizing is one of the most common processes in the heat treatment of ductile iron. As cast iron in the air medium (ie oxidizing atmosphere) heating, the surface of the reaction with oxygen, generating oxide layer. According to the production practice, we believe that the color and morphology of the oxide layer on the surface of ductile iron can roughly determine the normalizing heating temperature. The relationship between the two is as follows: 1. Normalizing temperature is 800 ~ 880 ℃, the color of the oxide skin red mixed color. As the heating temperature increases, the color changes from shallow to deep; with the extension of the holding time, the oxide scale changes from film to fluff.