Heat treatment method for 18CrNi4A steel spiral bevel gear

Abstract

The invention discloses a heat treatment method for an 18CrNi4A steel spiral bevel gear. The heat treatment method comprises the following steps that (1) copper plating protection is carried out on parts, except a tooth part, of a workpiece; (2) first carburizing treatment is carried out on the workpiece; (3) copper is removed from the whole workpiece, and then copper plating protection is carried out on other parts of the workpiece except the tooth part and the outer circle; (4) the workpiece is subjected to second carburizing treatment; and (5) quenching is carried out on the workpiece, then subzero treatment is carried out on the workpiece, and then tempering treatment is carried out. According to the method, the process control problem of different carburizing depths of different parts in the prior art is solved, the problem of low precision of two-time carburizing depth control is solved, a two-time carburizing superposition technology is adopted, and quenching-subzero treatment-tempering treatment is performed after carburizing, so that different requirements of different parts of the workpiece on the carburizing depths can be met, the carburizing depth of each part can be accurately controlled, and the performance requirement of the carburized workpiece can be ensured.

Description

technical field [0001] The invention relates to a heat treatment method, in particular to a heat treatment method for a 18CrNi4A steel spiral bevel gear. Background technique [0002] Aviation gears are key components of aero-engines, and reliable and accurate gear transmission is a necessary condition to ensure engine life. In order to improve the fatigue strength and wear resistance of the gear surface and increase the life of the gear, the surface of the gear and the bearing raceway are often carburized, and after quenching, parts with high surface hardness and high toughness are obtained. 18CrNi4A steel is a commonly used carburized gear steel. When the carburized layer depth is ≥ 1.0mm, the carburized layer depth fluctuates greatly, especially for parts that require different carburized depths in different parts. It is difficult to achieve the carburized layer depth with the existing technology. precise control. Aviation products involve a spiral bevel gear part, whic...

AI Technical Summary

Problems solved by technology

18CrNi4A steel is a commonly used carburized gear steel. When the carburized layer depth is ≥ 1.0mm, the carburized layer depth fluctuates greatly, especially for parts that require different carburized depths in different parts. It is difficult to achieve the carburized layer depth with the existing technology. precise control of

Aviation products involve a spiral bevel gear part, which requires the carburizing depth of the teeth to be 1.75-1.95mm, the carburizing depth of the outer circular runway to be 0.95-1.1mm (measured to HV550), and the hardness of the carburizing surface to be ≥ 58HRC, while the existing technology It is difficult to achieve precise control of the carburizing depth and performance of each part of the part