Abstract It is crucial to control and minimize the geometrical distortions resulted from the application of carburizing and quenching processes. This is particularly of the utmost importance for high quality steel products such as power transmission components which require high performance and dimensional precision in the range of micrometers. Carburized steel components are quenched from hardening temperature to room temperature to acquire a very hard martensitic layer (case). During the quenching process, due to the phase transformation-induced volumetric expansion in case and the interior region (core), unwanted dimensional changes may occur. In the present work, the effects of a modified hardening temperature and different soaking times on the core microstructure, the final dimensional stability and the mechanical properties are systematically investigated. Navy C-ring specimens are employed to quantify and correlate the effect of the developed microstructural constituents, magnitude of distortion, distribution of residual stresses and hardness values (macro, micro and nanohardness). Mini-tensile specimens are additionally fabricated out of the Navy C-rings’ core to evaluate the overall tensile behavior of the developed microstructures. The results show that by application of the modified hardening temperature the quenching-induced distortion can be reduced up to 27% while retaining the hardness properties of the case and core similar to that in the reference specimens which are quenched from a typical hardening temperature. The overall tensile properties of the core microstructures developed by the reference and modified heat treatments also show a nearly similar behavior.

中文翻译：

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渗碳钢部件的微观组织调整以减少淬火引起的变形

摘要 控制和最小化渗碳和淬火工艺应用导致的几何变形至关重要。这对于要求高性能和微米级尺寸精度的高品质钢产品（例如动力传输部件）尤为重要。渗碳钢部件从硬化温度淬火到室温，以获得非常坚硬的马氏体层（案例）。在淬火过程中，由于外壳和内部区域（核心）的相变引起的体积膨胀，可能会发生不需要的尺寸变化。在目前的工作中，修改后的硬化温度和不同的保温时间对核心微观结构的影响，系统地研究了最终的尺寸稳定性和机械性能。海军 C 形环试样用于量化和关联已开发的微观结构成分、变形量、残余应力分布和硬度值（宏观、微观和纳米硬度）的影响。微型拉伸试样另外由海军 C 型环的核心制成，以评估开发的微观结构的整体拉伸行为。结果表明，通过应用修改后的硬化温度，淬火引起的变形可以减少高达 27%，同时保持与从典型硬化温度淬火的参考试样相似的壳和芯的硬度特性。