Deformation rectifying method for plate carburizing and quenching gears and special tool for deformation rectifying method

Abstract

The invention relates to a deformation rectifying method for plate carburizing and quenching gears, and belongs to the technical field of metal thermal treatment. The method comprises steps of measuring and selecting, pre-moving stress, preparing a tool, mounting a workpiece, re-quenching, tempering and the like. By adopting the deformation rectifying method, the large end of a common normal line of a to-be-rectified gear faces downwards and is in direct contact with a tray higher than the gear, so that the cooling speed of the part of the gear can be reduced, thermal treatment expansion of the part is relatively small, and the phenomena of a relatively shallow carburized layer and a gear root step caused by too great follow-up milling amount due to secondary quenching are avoided; and meanwhile, the cooling speed for the upper end of the gear is relatively high, and the thermal treatment expansion is greater, so that the defect of a relatively small size of the common normal line after primary carburizing and quenching is compensated.

Description

technical field [0001] The invention relates to a method for correcting heat treatment deformation, in particular to a method for correcting deformation of disc-type carburized and quenched gears, and also relates to a special tool for realizing the method, which belongs to the technical field of metal heat treatment. Background technique [0002] Practice has shown that after carburizing and quenching of disc gears, the possibility of deformation such as ellipticity, taper, and end face runout exists. If it is not controlled, it is easy to exceed the scope of the process permit, resulting in no machining allowance in subsequent precision machining, resulting in scrap. [0003] The existing heat treatment deformation control is not good for disc carburizing and quenching gears, and the machining allowance before carburizing and quenching often has to be increased. As a result, not only the subsequent processing volume is large, but also the retained carburized layer is thin,...

AI Technical Summary

Problems solved by technology

However, theory and experiments have shown that the above-mentioned technical solution can only establish a gradually changing temperature field with a small gradient due to the heat conduction of the quenching medium itself, which is difficult to meet the demand for compensating for large deformations, especially when the medium used is quenching oil. To avoid exceeding its flash point, the temperature rise is limited, so the actual required temperature field cannot be established

[0005] On the other hand, the quenching temperature of the gear is usually around 840°C, and the limited temperature gradient managed to be established in the quenching medium has little compensation effect compared to the heat capacity of the gear itself, so it is actually difficult to achieve the purpose of suppressing deformation

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