The difference between vacuum heat treatment furnace atmospheric furnace and vacuum furnace
First, vacuum heat treatment furnace atmosphere.
1) In a small non-oxidation heat treatment technology trends, the most important development of vacuum atmosphere furnace and vacuum heat treatment rapidly. In the present fewer species, mass production, especially carbon steel bright quenching and general alloy structural steel, and annealing, carburizing, carbonitriding quenching gas Nitrocarburizing still controlled atmosphere for the main application means. So vacuum heat treatment furnace atmosphere is still a major part of advanced heat treatment technology.
2) to prepare the atmosphere gas source. Mastering and promotion of controlled atmosphere process, problem solving atmosphere come a long way. The first endothermic atmosphere furnace is mainly used liquefied petroleum gas, namely high purity propane or butane. In recent years has confirmed that China's abundant natural gas resources for the preparation of endothermic methane atmosphere created good conditions. Do not use raw type atmosphere furnace straight and can not be ignored is a way.
3), a heating device. Sealing high degree of automation and multi-purpose furnace multi-purpose furnace production line, the production of flexible large, applicability, and thus wide application
4), a vacuum atmosphere furnace heat treatment process. Carburizing. Carburizing temperature is one of the carburizing technology trends. Carburizing temperature increase can significantly improve productivity and save energy. Electric radiant tube material can be used to do this research and development is a priority above 1000 ℃, low pressure carburizing technology development and improvement for the realization of high-temperature carburizing (1040 ℃) to create the conditions. Steel case depth requirements are generally more conservative, sometimes very blind. It seems necessary to study the factors that determine the mechanical case depth, and to explore the possibility of reducing the diffusion layer requirements.
Carbonitriding lower temperature than carburizing, small distortion of the workpiece. In the case depth is 0.6mm below the penetration rate is close to 930 ℃ carburizing. Likely to occur when abnormal tissue carbonitriding steel, surface hardness after quenching phenomenon has decreased, the diffusion layer has more residual austenite. How to choose the process, give full play to the potential of carbonitriding is still worth exploring. It has been advocated in the past excessive concentration carbonitriding, have had when carbonitriding steel surface carbon content of 0.6%, with the best mechanical properties of the report, for which different opinions. It seems necessary to grasp these laws, the production process of the preferred helpful. Rolling in the past and now have on the implementation of carbonitriding to improve the contact fatigue strength reported. E.g. AISI52100 (equivalent GCr15) steel balls and rollers by past quenching and tempering to carbonitriding, destroy life quenching and tempering, bearing increased 2.42 times. It seems to realize the full potential carbonitriding process there is much work to be done.