The gears installed in the transmission, reducer and differential undertake the tasks of changing speed, output torque and driving the vehicle. When the gear works, all the torque acts on the meshing teeth to make them bear great bending stress and contact stress, and periodically acts on each tooth...
Shanghai Tractor internal combustion engine Co., Ltd. studied the spline hole distortion of xf-125 primary transmission gear, carried out tests from the aspects of raw materials, heat treatment process and cold working stress, explored many influencing factors of spline hole shrinkage, and took corresponding technical measures to solve this...
1. Cracks 1) In the carburizing diffusion stage, the carbon potential is high, the carburizing layer carbon concentration is too high and the gradient is large, and the tooth surface peels and falls off during grinding. Solution: control the carbon potential between 1.0 ~ 1.20% C in the strong...
Whether carburizing quenching, carbonitriding quenching, induction heating quenching or overall heating quenching, the possible heat treatment defects during gear quenching and cooling mainly include: (1) The hardness in quenched state is insufficient, the hardness is uneven, and the quenching and hardening depth is not enough. (2) The core hardness...
Various defects produced during heat treatment of gears will have potential or obvious adverse effects on their quality and service life. The effects of several main defects are briefly described. 1. Cracks Local fracture of metallic materials is called crack. Local fracture. Cracks not only directly destroy the continuity...
The center of carburized gear is required to have a certain hardness. When the hardness is low, the yield point of the gear material is reduced, which is easy to produce plastic deformation in the center, which reduces the anti peeling performance of the gear surface hardening layer and...
The surface hardness of carburized gear is too shallow, which not only reduces the anti peeling performance of surface hardened layer, but also reduces the service life. 1. Cause analysis (1) In the carburizing process, the carburizing time is too short, the carburizing temperature is low, the carburizing layer...
1. Defect content Including coarse martensite, excessive retained austenite as shown in figure (a), excessive surface carbides as shown in figure (b), out of tolerance of ferrite in the center as shown in figure (c), surface oxidation decarburization, etc. On the one hand, the out of tolerance of martensite,...
Gear heat treatment deformation is affected by many aspects, such as part shape, raw materials, forging and preliminary heat treatment, workpiece residual stress before cold and hot processing and heat treatment, and heat treatment process methods. Therefore, gear heat treatment deformation control should be solved from the comprehensive control...
The problem of spline hole distortion of xf-125 primary transmission gear by China First Tractor internal combustion engine company is studied. Experiments are carried out from the aspects of raw materials, heat treatment process and cold working stress. Many influencing factors of Huajian hole shrinkage are explored and corresponding...