Abstract

Scuffing is a catastrophic failure that causes significant surface damages such as plastic flow and welding with a marked increase in friction, wear, temperature and noise. In this study, variations in the crystal grain structure of a steel surface was analysed in situ during the scuffing process using a synchrotron X-ray diffraction system, combined with a visible camera and a near-infrared thermometer. The in situ observation system was synchronously operated to capture a contact area between a rotating sapphire ring and a stationary bearing steel pin. The Debye–Scherrer ring diffracted from the contact area was captured by a two-dimensional detector. The scuffing behaviour could be classified as either micro scuffing or macro scuffing. During the micro scuffing period, plastic flow occurred intermittently with a significant temperature rise of approximately 1000 °C. During the macro scuffing period, heat was continuously generated over the contact area. When plastic flow occurred, the captured Debye–Scherrer ring indicated the orientation of crystal grains as well as a phase transformation from martensite to austenite. This study constitutes the first in-situ observation of the behaviour of crystal grains in the dynamic recrystallisation process occurring during the scuffing process.

Graphic Abstract

中文翻译：

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用同步辐射X射线衍射原位观察钢表面划伤过程中的晶粒取向

摘要

划伤是一种灾难性故障，会导致明显的表面损坏，例如塑料流动和焊接，并且摩擦，磨损，温度和噪音会明显增加。在这项研究中，使用同步加速器X射线衍射系统，结合可见相机和近红外温度计，在划伤过程中就地分析了钢表面晶粒结构的变化。同步运行原位观测系统，以捕获旋转蓝宝石环和固定轴承钢销之间的接触区域。从接触区域衍射的德拜-谢勒环被二维探测器捕获。划伤行为可分为微划伤或宏观划伤。在微擦伤期间 塑性流动是间歇性发生的，温度升高约1000°C。在宏观磨损期间，在接触区域上连续产生热量。当发生塑性流动时，捕获的Debye–Scherrer环表明晶粒的取向以及从马氏体到奥氏体的相变。这项研究是对磨损过程中发生的动态再结晶过程中晶粒行为的首次原位观察。

图形摘要