Research On The Carburizing In The Sealed Box Multi-purpose Furnace

Because of excellent airtightness, high precision temperature atmosphere control and high degree computer automation, the Seal-box multi-purpose furnace is widely used in various chemical heat treatment procedures, such as gas carburization and carbonitriding, and it has been the most extensively used in temperature atmosphere control heat treatment equipment at present. In China, most of matured seal-box multi-purpose furnace equipments and critical components are introduced from foreign countries. However, due to being short of service time and inapprehensionin about the equipments, most of these equipments use traditional carburizing technology of well-furnace, or use references technique from manufacturers. These results in solving problems mostly judging by experience which is out-dated of well-furnace, also the technique doesn’t correspond with multi-purpose furnace. It may resolve problems in short time, but simultaneously brings potential quality accident over a long period of time. Combining with actual application of products and equipments, making use of test method to research on carburizing technique of seal-box multi-purpose furnace systematically, looking for the balance point of equipment, quality and production efficiency in process technology, making full of the equipment ability and the application of technique level is an important parts of processing technology research in heat-treatment spot, also is the principle of this paper.The quality of gear heat treatment has an important influence on failure under heavy load operating condition, and the external feedback rate of loader axle pinion is the first place for a long time. Improving the carburizing quenching quality of pinion by the way of heat treatment has an important significance on decreasing external feedback loss and advancing the quality of product. So it has long-term impact on improving product technology and increasing market income that analyzing and proofing various processing parameters systematically which have an effect on carburizing quality of pinion, and optimizing the processing parameters of pinion to ensure the carburizing quality of pinion in seal-box multi-purpose furnace by experiment and professional theory.The deformation of heat treatment is a permanent topic in profession. The study object of this paper is spline deformation carburized in seal-box multi-purpose furnace, using statistics analysis and experiment design to research the result of processing deformation, combining with profession theory to control the deformation. The process and method of experiment have an important reference and guidance significance on the research of heat treatment deformation.This disquisition includes six sections:Firstly, introduce the equipment, technique, carburizing actuality of the Seal-box multi-purpose furnace, bring up DOE method to study the Seal-box multi-purpose furnace carburizing technology and depict the practical industry value and technology.Secondly, analyze the Seal-box multi-purpose furnace carburizing technology features, implementation and parameter control system to find the major factors that influence the control system and stable situation of the equipment by the way of experiment.Thirdly, combining the gas carburizing and carbon potential control theory, utilizing the full factor experimental design method finds the assistant control method which have the least influence to carbon potential fluctuation and oxygen probe measuring error instill atmosphere flow velocity, Also find a cheap method to help control the carbon potential.Fourthly, based on the bevel gear as the study object, which is one of the external feedback typical parts produced by the Seal-box multi-purpose furnace, and combining the heat treatment and DOE theory, optimizes the carburizing the technology.Fifthly, basing on the special shape parts, the long castellated shaft, as the carburizing quenching distortion study object, through analyzing the shaft structure and present quality situation, combining the profession and DOE theory, finds out the critical factors of castellated distortion and optimizes the carburizing the technology.Lastly, sum up the paper and give an outlook of the technology.