渗碳淬火齿轮氧化皮探究

Research on Oxide Scale on Carburized and Hardened Gears

经渗碳淬火的零件表面通常会产生极薄的氧化皮。为揭示氧化皮的实质及其形成原因,用17CrNiMo6铜齿轮进行了热处理工艺试验：在密封箱式炉内430~450℃预氧化,930℃渗碳,在空气炉中660℃高温回火,在密封箱式炉内从820~830℃油淬和180℃低温回火。结果表明,齿轮表面的氧化皮成分主要是FeO,厚度10μm左右,是渗碳后在空气炉中高温回火所致。将齿轮在氮气保护炉中高温回火而不是在空气炉中回火可避免氧化皮的产生。

An extremely thin oxide scale will generally form on the components subjected to carburizing and hardening. A trial heat treatment process, which consists of pre-oxidizing at 430 to 450℃, carburizing at 930 ℃in seal box furnace, high tempering in air furnace at 660℃, oil-quenching from 820 to 830℃ in seal box furnace, and low tempering at 180℃, was performed with the use of 17CrNiMo6 steel gears to reveal substance of the oxide scale and the factors responsible for it. The results show that the oxide scale on the gear mainly is FeO about 10μm thick, and derived from the high tempering in an air furnace following the carburizing. The oxide scale may be avoided by the high tempering in a furnace provided with nitrogen rather than air furnace for the gear or the others.