Method for judging complete carburization of tooth crest

Abstract

The invention provides a method for judging complete carburization of a tooth crest, which comprises the following steps: intercepting the tooth profile of a gear, and obtaining a tooth profile surface and the tooth crest according to the tooth profile; drawing a normal line of the intersection point A and a normal line of the intersection point B from the intersection point A and the intersectionpoint B to the interior of the tooth profile according to the intersection point A and the intersection point B, and obtaining an intersection point O in the tooth according to the normal line of theintersection point A and the normal line of the intersection point B; measuring the distance n between the intersection point A and the intersection point O; calculating seepage layer depth ranges L,Lmax and Lmin increased by the effective carburized layer due to overlapping of the front edge low-carbon concentration areas of the carburized layer; and according to the n, the Lmax and the Lmin, judging whether the tooth crest is completely carburized, the Lmax is the maximum carburized layer depth which is increased by an effective carburized layer after the front edge low-carbon concentration areas of the carburized layer are overlapped, and the Lmin is the minimum carburized layer depth which is increased by the effective carburized layer after the front edge low-carbon concentration areas of the carburized layer are overlapped.

Description

technical field [0001] The invention belongs to the technical field of carburizing heat treatment surfaces, and relates to a method for judging complete carburization of tooth tops. Background technique [0002] The traditional view is that only small modulus gears have the risk of complete carburization of the addendum. In fact, for gears with a relatively high effective modulus, when the number of teeth is large, the width of the addendum will become smaller. If a given carburization is designed The depth of the layer is unreasonable. Even if the top of the tooth is protected by copper plating, during the carburizing process, the active carbon atoms continue to diffuse through the tooth surface and the heart tissue of the tooth, which can also cause complete carburization of the top of some gears with a relatively large modulus. carbon phenomenon. [0003] For small and medium gears such as aviation and automobiles, the depth of the carburized layer is mostly concentrated...

AI Technical Summary

Problems solved by technology

[0003] For small and medium gears such as aviation and automobiles, the depth of the carburized layer is mostly concentrated in the range of (0.8-1.3) mm. After the tooth top is completely carburized and quenched, the hardness of the tooth top fully carburized area is greater than HRC55, and it is quenched with the tooth surface carburized area. After the hardness is similar, the brittleness of the addendum is greatly increased. Under the action of impact load, the addendum is easy to break and will have serious consequences.

At present, there is no relevant literature report on the method of judging in advance whether the carburized layer depth given by the design can produce the complete carburization of the tooth top through the tooth shape parameters of the relevant gears.

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