Carburizing and quenching of truck gears is a key process in the process of gear quality control. Many key characteristics of truck gear need to be realized through this final heat treatment. The quality of heat treatment directly affects the tooth surface meshing and service life of truck gear. At present, the process of heat treatment of truck gears in the world is mainly gas carburizing process. Generally speaking, for the carburizing and quenching process of truck gears, high quality is guaranteed by advanced equipment. With the rapid popularization of highly flexible automatic manufacturing system and the technological progress in the fields of materials, heat treatment and computer, the traditional gas carburizing equipment is developing towards flexible manufacturing system. The advanced flexible line for heat treatment of truck gears has the following characteristics:
- Parts with different layer depth requirements can be processed synchronously;
- It can accurately control the process parameters;
- The whole process is controlled and tracked by microcomputer.
Advanced computer control technology can not only control the carburized layer depth and surface hardness, but also control the surface carbon content, the morphological distribution of carbides and residual austenite in the structure, as well as the surface hardness gradient, so as to obtain the best carburized layer quality and the smallest deformation, and improve the product quality. In recent years, the use of high-pressure gas quenching vacuum and plasma carburizing process in truck gear processing industry has achieved great success, completely solved the internal oxidation problem that cannot be overcome by conventional equipment, and brought a series of advantages such as no pollution, reduced energy consumption and small deformation, which will also be a direction of truck gear heat treatment. German ALD uses gas quenching instead of oil quenching in carburizing steel hardening for the production of high-grade car gears. The core hardness of truck gears is higher than oil quenching and the deformation is relatively small. It can be predicted that with the continuous improvement and improvement of the level of truck gear heat treatment production line, the quality of heavy truck gears will be improved to a new level.