Driven gear heat treatment method

Abstract

The invention relates to a driven gear heat treatment method. According to the scheme of the driven gear heat treatment method, a copper plating layer on the surface of the area where carburization is needed is removed through machining after copper plating treatment is carried out on the whole surface of a driven gear workpiece, then, carburization treatment is carried out, and the purpose that carburization is carried out only in the local area can be achieved; before quenching treatment is carried out, the cavity area, likely to be damaged, of the copper plating layer is coated with an anti-carburization coating, dual-layer protection is carried out on the cavity area, coal oil is added during quenching for atmosphere protection, decarburization on a carburization face can be effectively prevented, carburization can be effectively avoided due to the protection of the anti-carburization coating on the cavity area, and follow-up machining is convenient; and a pressure quenching machine tool is used for oil cooling after quenching, and shrinkage distortion is effectively reduced. By means of the method, the technical effects that carburization is carried out on the designated area of the driven gear, a carburization layer is free of decarburization after carburization is completed and carburization is avoided for the cavity area can be effectively achieved, volume production is easy, and the cost is low.

Description

technical field [0001] The invention relates to the technical field of heat treatment of 18Cr2Ni4WA parts, in particular to a heat treatment method for a driven gear made of 18Cr2Ni4WA. Background technique [0002] 18Cr2Ni4WA has good processability and fatigue resistance, and has relatively ideal hardenability, toughness and good carburization controllability. It is an irreplaceable material for the production of heavy-duty transmission parts. Shafts, crankshafts, spline shafts and other special wear-resistant parts are widely used in the manufacture. Carburizing and nitriding the surface during manufacture is a conventional method to improve the surface hardness of parts. [0003] As a part with special requirements on surface hardness, gears often only require partial carburizing, such as figure 1 As shown, the driven gear used in the aero-engine is made of 18Cr2Ni4WA, that is, the areas A, B, C, D, H, N in the figure and the area of ​​the inner spline E are required to...

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Problems solved by technology

[0003] As a part with special requirements on surface hardness, gears often only require partial carburizing, such as figure 1 As shown, the driven gear used in the aero-engine is made of 18Cr2Ni4WA, that is, the areas A, B, C, D, H, N in the figure and the area of ​​the inner spline E are required to be carburized, and F is the cavity area. No carburization is allowed in this area. In the production process, whether it is gas carburization, liquid carburization or solid carburization, it can only be processed on the surface of the part as a whole, and it is difficult to deal with such special requirements.

After the carburizing of the driven gear is completed, the inner spline E area needs to be machined. During the machining process, the surface of the adjacent cavity area is easily affected, and the surface coating is damaged. In the subsequent quenching, kerosene is often added as a Protect the atmosphere to prevent decarburization of the carburized layer. At this time, it is very easy to cause the cavity area to be carburized. After quenching, the hardness reaches the hardness of the carburized layer, and the subsequent cavity cannot be processed.

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