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一、前言 最近,球墨铸铁的离子氮化法,因为没有公害,气体使用量少,处理温度低,处理零件的变形量小,可以提高耐磨性、耐热胶着性、耐蚀性以及疲劳强度,所以以汽车零件为主,正在被广泛的利用。 根据机械零件的要求,可使用珠光体系及铁素体系作为离子氮化前的组织。需要高的表面抗压强度时,使用珠光体系。珠光体系在接近570℃下进行离子氮化处理时,如果处理时间长,使Fe_3C石墨化元素Si含量多,那么基体珠光体中的Fe_3C就石墨化,引起硬度降低及尺寸变化,不耐使用。作为珠光体的稳定剂,加入少量的Sn最有效,在工业上被广泛利用。 例如:美国通用汽车公司,在球墨铸
I. Introduction Recently, the ductile iron ion nitriding method, because there is no public hazard, less gas usage, low processing temperature, the deformation of the processing of small parts, can improve the wear resistance, heat resistance, corrosion resistance and fatigue strength , So the main automotive parts, is being widely used. According to the requirements of mechanical parts, pearlite system and ferrite can be used as the pre-ion nitriding organization. When high surface compressive strength is required, pearlite is used. Pearlescent nitriding at near 570 ℃, if the processing time is long, so that the amount of Si in the Fe 3 C graphitized element is too large, then the matrix pearlite Fe 3 C is graphitized, resulting in reduced hardness and dimensional changes, intolerant to use. As a pearlite stabilizer, adding a small amount of Sn is most effective and is widely used industrially. For example: United States General Motors, in ductile cast