Quenching method for high alloy carburizing steel gear

Abstract

The invention relates to a quenching method for a high alloy carburizing steel gear. The method comprises the following steps that the carburized gear is heated along with a furnace for the first time till the temperature is 860 +- 10 DEG C, and the heat insulation time is 2-3 h; the gear is quickly cooled to be 780 +- 10 DEG C for the first time, and the heat insulation time is 3-4 h; the gear is quickly heated till the temperature is 840 +- 10 DEG C for the second time, and the heat insulation time is 2-3 h; the gear is quickly cooled to be 700 +- 10 DEG C for the second time, and the heat insulation time is 3-4 h; the gear is quickly heated till the temperature is 820 +- 10 DEG C for the third time, and the heat insulation time is 2-3 h; the quenched gear is placed into a tempering furnace, heating is conducted till the temperature is 180-220 DEG C, low-temperature tempering is conducted in the environment with the temperature being 180-220 DEG C, and heat insulation is conducted for 3-4 h; and the gear is taken out of the furnace and subjected to air cooling till the temperature reaches a room temperature. According to the quenching method for the high alloy carburizing steel gear, martensite of the surface layer of the gear can be effectively refined, the residual austenite content is reduced, and thus the metallographic structure of the surface of the gear is optimized; and meanwhile, surface hardness, abrasive resistance, fatigue strength and the plastic tenacity index of the gear are improved.

Description

technical field [0001] The invention relates to a quenching method for high-alloy carburizing steel gears, belonging to the technical field of heat treatment. Background technique [0002] Gears are one of the commonly used transmission parts in reducers and transmission mechanisms. They are mainly used to support transmission parts, transmit torque and bear loads. During the running process, there are both rolling and sliding between the meshing tooth surfaces of the gears, which are subjected to both pulse stress and alternating bending stress, and carburizing and quenching is still one of the main surface strengthening methods of the gears, so the gears need to be heat treated To have good hardness, wear resistance, high bending fatigue strength and impact resistance. [0003] In recent years, with the development of heavy-duty gears, high-alloy carburized steel gears can greatly improve the core toughness, surface wear resistance and fatigue strength of gears, making hi...

AI Technical Summary

Problems solved by technology

Although this method can meet the technical requirements of general gears, in-depth research shows that there are the following deficiencies: after carburizing and quenching, the martensite needles on the surface layer are relatively thick, the content of retained austenite is relatively large, and the surface hardness of the gear is low, which will reduce the wear resistance of the gear. Wear resistance, toughness and comprehensive mechanical properties

Images