Heavy Duty Automobile Transmisson Gear Materials And Heat Treatment Process Of The Experimental Study

For the automobile transmission, gear are the key parts. In this paper, through applying the metal material alloying principle and HT technology to analyse the chemical composition, mechanical performance characteristics of the different series steel and choose the materials ,CrNi2MoH 20 and 17CrNiMo6H, generally used in domestic and abroad for heavy transmission gear and to do technology research according to their characteristics . Based on the analysis of the continuous change curve of the selected materials, conduct the two kinds of different pre-heat treatment process,then get the best pre-heat treatment process for production according to the final testing result.Researching the carburizing, quenching ,tempering processes of the two kinds of materials ,20 CrNi2MoH steel and 17 CrNiMo6H. Based on the alloy composition and content, the heat treatment characteristics of the two materials, formulate two sets of different carburizing quenching tempering processes to do comparative analysis from the surface hardness , the core hardness, microstructure, the effective hardening case, as well as to discuss the quality control points in the process and put forward the defect easily occurred during the carburizing quenching process, causes and preventive methods . Eventually find the suitable heat treatment process for the company's heat treatment equipment to guide production. Finally research the reinforce processing method to the processed gear and improve the fatigue strength of the gear.