Thermal treatment method for internal spline gear with small modulus

Abstract

The invention discloses a thermal treatment method for an internal spline gear with small modulus. The method has a principle similar to a press quenching and is characterized in that: a core rod with the size consistent to the size of a spline internal hole is adopted, as the size of the spline internal hole is basically consistent to the size of the core rod, the core rod is inserted into the spline internal hole when a spline is heated to the quenching temperature and is taken out of a furnace for quenching; due to the principle of expansion with heat and contraction with cold, the spline and the core rod are tightly pressed together after oil feeding; due to the limitation of the size and the shape of the core rod, the deformation is limited in a defined range. According to the thermal treatment method, a controllable atmosphere heat treatment furnace is adopted for carburization; and through controlling furnace temperature, insulation time and carbon potential and selecting a proper core rod for quenching thermal treatment, the deformation requirement after carburization and quenching of the spline internal hole can be met. Meanwhile, the grinding step is omitted, the use requirements of a carburized layer and the hardness of the core part of a part can be ensured.

Description

technical field [0001] The invention relates to a heat treatment method, in particular to a small modulus internal spline gear heat treatment method. Background technique [0002] 9310 steel is a material commonly used in aviation. The small modulus internal spline gear made of 9310 steel has both external gear and internal spline. The internal spline has a small through hole diameter (diameter less than 20mm), modulus Small (modulus not greater than 1), tooth height and tooth thickness are relatively thin. Internal splines and external gears are required to have good wear resistance, so chemical heat treatment is usually used, and carburizing and carbonitriding are commonly used to achieve the designed performance and meet the use requirements. At present, gears and internal spline parts have different degrees of quenching deformation after carburizing. In order to control this deformation, a certain amount of carburizing layer allowance is usually left, and the quenching ...

AI Technical Summary

Problems solved by technology

However, it is difficult to ensure that the depth of the carburized layer and the core of the part meet the hardness requirements by controlling the deformation by grinding