A Study On Heat Treatment Process Of Gear Shaft In The Gearbox Of Heavy-duty Automobile

In the carburizing heat treatment process,in order to obtain hardness and qualified internal organization,the need for a long time at high temperature,the effect of thermal stress and structural stress,after cooling the work piece has certain d eformation,at the same time to meet the requirements of the internal microstructure and hardness of qualified,deformation small,difficult.The key problem of this paper is how to adjust the parameters of the process,including the temperature,cooling medium and so on.The object of this paper is the Chongqing machine tool group of heat treatment of key products branch of research,the research results will improve the heavy vehicle transmission gear shaft production efficiency,reduce production cost and meet the requirement of mass production products,technology also has reference value to the similar products.This research in-depth and rigorous in the heat treatment process of heavy vehicle transmission gear pump was carried out,looking for methods to determine the optimal gear shaft in the machining process parameters,in obtaining qualified heart organization and hardness at the same time,to meet the requirements of gear tooth precision technology,to improve production efficiency and reduce production cost the purpose of.By analyzing the theory of heat treatment and the practical engineering experience,this paper analyzes the characteristics of the gear shaft of heavy duty automobile transmission gear,and designs the experimental scheme and the experiment plan of carburizing quenching process.Process experiments under different parameters,and to understand the influence of process parameters on Microstructure and dimensional accuracy of gear shaft,so as to determine the optimal process parameters,microstructure and size to satisfy the accuracy requirement.After mass production,using SPC method to calculate the value of CPK,the continuous extraction of 25 groups of data acquisition object respectively,surface hardness,hardness of the core and the depth of the hardened layer,demonstrates the best technology and equipment to ensure the rationality and reliability of process product yield on the required standard,and can be used as a continuous improvement process.On the basis of.