The Preparation And Organizational Performance Analysis Of18CrNiMo7-6Carburized Gear Steel

18CrNiMo7-6carburized gear steel was chose as the experimental material. Inorder to better adapt to market demand, to meet the requirements of users and thesubsequent production, the study of manufacture process and the organizationalperformance analysis of18CrNiMo7-6carburized gear steel were accomplished. Itspurpose was to perfect the preparation technology of18CrNiMo7-6carburized gearsteel, to reasonable control18CrNiMo7-6carburized gear steel grain size andmicrostructure to improve organizational performance, and to prepare for rawmaterials base for the development of the downstream equipment manufacturingindustry.The preparation of18CrNiMo7-6carburized gear steel was completed.According to the experience of the early production preparation, the reasonable teststeel for process route was developed, and the process effect on the properties oftest steel was analyzed, so that the attention matters and control points in theprocess were summarized. Then the preparation difficulties and process controls of18CrNiMo7-6carburized gear steel were earmarked to obtain18CrNiMo7-6carburized gear steel with better organizational performance.In order to obtain excellent microstructure of18CrNiMo7-6carburized gearsteel, with grain size as reference object, the18CrNiMo7-6carburized gear steel ingrain size control was analyzed. According to the grain size tests scheme, theperformance tests of18CrNiMo7-6carburized gear steel samples were analyzed andthe chemical composition influence (alloying elements) on the grain size andorganization performance were discussed, the optimum composition choice andcontrol were developed. Focus on comparative analysis of grain size andorganizational performance with different level of Al/N ratio, the influencingmechanism of Al/N on grain size was discussed, which was the AlN control theoryof the grain boundary migration.Under different heat treatment states, the microstructure and mechanicalproperties18CrNiMo7-6carburized gear steel were analyzed, to obtain laterreasonable heat treatment process conditions of18CrNiMo7-6carburized gear steel.The microstructure and mechanical properties18CrNiMo7-6carburized gear steel on the circumstance of primitive annealing state, normalizing treatment andtempering treatment were earmarked, the influence of heat treatment process onsample steel and influencing mechanism were discussed, and the later relativelyexcellent heat treatment system of18CrNiMo7-6carburized gear steel wasdetermined.