Address:Auto Parts Industrial Park, Jinji Town, Tianchang City, Anhui Province
Distortion control of ring carburizing and quenching distortion in large heavy duty gear of 17CrNiMo6 steel
Because of the development of modern industry, the requirement of the gear transmission is more and more high, which is required to have the comprehensive mechanical properties such as wear resistance, surface contact fatigue and bending fatigue. Heat treatment is a key process in the manufacturing of gear manufacturing. The main problem is that the gear is the distortion of the gear. There are many factors that affect the distortion of the gear, and many of them interact with each other. It is difficult to control the distortion of the production.
Inner gear ring of large heavy load in large engineering machinery gear box is widely used, because its volume is large, and belong to the thin-walled structure, such parts of the abnormal change of not easy to control. In the carburizing and quenching process, if heating or cooling unreasonable cause uneven work sizing, resulting in gear ring distortion. The distortion of the inner ring gear mainly includes two aspects: the ellipse degree and the taper. This paper combines with the actual production situation, and the inner ring is controlled in the lower range.
From the process and tooling, the distortion of the inner ring gear is studied. The conclusion is:
1) the internal ring carburizing before adding a stress annealing process, the annealing temperature is much lower than the temperature, quenching temperature, and the heating rate is slow, which is conducive to the release of the stress.
2) the temperature rise and temperature of the inner ring can be reduced. The temperature difference caused by heat and the temperature of the /h can be reduced. The thermal stress and microstructure stress can be reduced to a certain extent.
3) the positioning sleeve can form a good fit with the inner ring in the quenching process, and can improve the heat transfer efficiency, and can improve the heat transfer efficiency, and reduce the distortion caused by the uneven quality.
4) in the process and the small scale production, the ellipse degree can be controlled in 0.70 ~ 0.28 mm, the taper control is 0.036% ~ 0.52 mm, and the average value of the internal gear ring is 0.40 and 0.027% respectively.