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Abstract：
Today, there are many diagnostic methods and advanced measurement techniques enabling the correct diagnosis and assessment of the type and degree of wear of cogwheels (gears, pumps, etc.). The present study presents an analysis of the surface defects of a cogwheel of an oil pump prototype (3PW-BPF-24). The test object operated for a certain number of hours under controlled operating and environmental parameters. The damage to the surface layer was caused by fatigue phenomena and previous thermo-chemical treatment. On the basis of the significant percentage share (~30%) of residual austenite in the volume of the diffusion layer, a hypothetical conclusion was drawn about the suboptimal parameters of the thermo-chemical treatment process (in relation to the chemical composition of the analyzed pinion). A large number of research studies indicate that the significant presence of residual austenite causes a decrease in tooth surface hardness, the initiation of brittle cracks, a sharp decrease in fatigue strength, an increase in brittleness and a tendency to develop surface layer cracks during operation. High-resolution 3D scans of randomly selected pitting defects were used in the detailed study of the present work. It was indicated that the analysis of the morphology of surface defects allowed some degree of verification of the quality of the heat/chemical treatment. The martensitic transformation of residual austenite under controlled (optimum) repeated heat treatment conditions could significantly improve the durability of the pinion (cogwheel). In the case analyzed, the preferred treatment was the low-temperature treatment. The paper concludes with detailed conclusions based on the microscopic and macroscopic investigations carried out.
摘要：
今天,有许多诊断方法和先进的测量技术，能够正确诊断和评估齿轮的类型和磨损程度(齿轮，泵,等。).本研究对油泵原型（3PW-BPF-24）的齿轮的表面缺陷进行了分析。测试对象在受控的操作和环境参数下操作一定的小时数。对表面层的损坏是由疲劳现象和先前的热化学处理引起的。基于扩散层体积中残余奥氏体的显著百分比(~30%),关于热化学处理过程的次优参数（与分析小齿轮的化学成分有关）得出了一个假设结论。大量的研究表明,大量的残余奥氏体的存在导致齿面硬度的降低,脆性裂纹的开始，疲劳强度急剧下降，脆性的增加和在操作过程中形成表面层裂纹的趋势。在本工作的详细研究中，使用了随机选择的点蚀缺陷的高分辨率3D扫描。结果表明，对表面缺陷形态的分析可以在一定程度上验证热/化学处理的质量。在受控（最佳）重复热处理条件下，残余奥氏体的马氏体相变可以显着提高小齿轮（齿轮）的耐久性。在分析的案例中，首选的治疗方法是低温治疗。本文根据所进行的微观和宏观研究得出了详细的结论。
