论文部分内容阅读
目前,在球墨铸铁热处理中,正火是最常用工艺之一。由于铸件在空气介质(即氧化性气氛)中加热,其表面会发生氧化脱碳。铸件表面形成氧化层,将使铸件尺寸减小,增加材料损耗。零件不加工表面存在脱碳层(例如球铁连杆),可降低疲劳强度,缩短使用寿命。
At present, normalizing is one of the most common processes in ductile iron heat treatment. As the castings in the air medium (ie oxidizing atmosphere) heating, the surface oxide decarbonization occurs. The oxide layer formed on the surface of the casting will reduce the size of the casting and increase the material loss. Decarburized layers (eg ductile iron bars) are present on the machined part surface to reduce fatigue and reduce service life.