Change of Ultrasonic Attenuation and Microstructure Evolution during Creep of SUS316L Austenite Stainless Steels
Change of Ultrasonic Attenuation and Microstructure Evolution during Creep of SUS316L Austenite Stainless Steels
复制标题
SUS316L奥氏体不锈钢蠕变过程中超声波衰减变化及组织演变
DOI：
10.2472/jsms.54.607
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
K. Takei
中科院分区：
文献类型：
--
作者：
T. Ohtani;K. Takei
电磁声谐振（EMAR）是一种利用电磁声换能器（EMAT）的非接触式谐振方法。这种方法没有额外的能量损失，导致固体中固有的超声衰减的测量。在这项研究中，EMAR应用于检测奥氏体不锈钢，SUS 316L的蠕变损伤。将材料暴露于973 K的温度下，在各种应力下。我们测量了超声衰减为1-8兆赫的频率范围内的蠕变先进。衰减系数对损伤累积的敏感性远大于速度。在整个寿命的60%和70%之间的短时间间隔内，衰减经历一个大的峰值，与应力无关。这种新现象被解释为由于微观结构的变化，特别是，位错的流动性。位错结构的TEM观察支持了这一点。该技术具有评估损伤进展和预测金属蠕变寿命的潜力。
Electromagnetic acoustic resonance (EMAR) is a contactless resonant method with an electromagnetic acoustic transducer (EMAT). This method is free from extra energy losses, resulting in the measurement of intrinsic ultrasonic attenuation in solids. In this study, the EMAR was applied to detect the creep damage of an Austenite Stainless Steel, SUS316L. The material was exposed to the temperature of 973K at various stresses. We measured ultrasonic attenuation for 1-8-MHz frequency range as the creep advanced. The attenuation coefficient exhibits much larger sensitivity to the damage accumulation than the velocity. In a short interval, between 60% and 70% of whole life, attenuation experiences a large peak, being independent of the stress. This novel phenomenon is interpreted as resulting from microstructure changes, especially, dislocation mobility. This is supported by TEM observations for dislocation structure. This technique has a potential to assess the damage advance and to predict the creep life of metals.