作者：张洪波¹, 岳斌^1,2, 邓晓光¹, 张燕南¹, 赵文政¹

作者单位：1. 河北大学质量技术监督学院, 河北 保定 071002;
2. 北京玻钢院复合材料有限公司, 北京 102101

关键词：超声衍射时差法;A扫;分辨力;温度

摘要：

针对温度变化引起超声衍射时差技术（time of flight diffraction，TOFD）测量结果误差的现象，以含不同预置缺陷Q235A试块为测试样品，采用TOFD超声检测技术，并结合A扫结果，研究不同温度对缺陷检测结果的影响。研究发现，当试块表面温度超过40 ℃时，底面小缺陷的检测难度会提高，检测结果的不稳定性提升；随着试块表面温度继续升高，TOFD测量缺陷的最小分辨率会降低到3 mm，同时小缺陷波的A扫波形已经无法从背景噪声中识别。通过比较不同温度下纵波在固体介质中传播速度，发现温度升高导致纵波速度衰减，进而导致仪器分辨力的下降和实际测量误差的增大。

The influence of temperature on the results of time of flight diffraction detection
ZHANG Hongbo¹, YUE Bin^1,2, DENG Xiaoguang¹, ZHANG Yannan¹, ZHAO Wenzheng¹
1. College of Quality and Technical Supervision, Hebei University, Baoding 071002, China;
2. Beijing Composite Materials Co., Ltd., Beijing 102101, China
Abstract: Aiming at the phenomenon that the change of temperature leaded to the measurement error of the time of flight diffraction (TOFD), the TOFD ultrasonic testing technique was used to test the Q235A specimens with different prefabricated defects, and the A-scan outcomes were used to study the effects of different temperature on defect detection. The results show that the difficulty in detecting the small defects on the bottom surface is increasing as the surface temperature of the specimens exceed 40℃, and the instability of the testing results will increase. As the surface temperature of the specimen increasing, the minimum resolution of TOFD in measurement defects will be reduced to 3 mm, and the small defect of A-scan waveform cannot be identified from the background noise. Compared with the propagation velocity of P-wave in solid medium at different temperatures, it is found that the P-wave velocity decays with the increase of temperature, which leads to the decrease of the resolution of the instrument and the increase of the actual measurement error.
Keywords: time of flight diffraction;A-scan;resolving power;temperature
2019, 45(3):41-45  收稿日期: 2017-11-07;收到修改稿日期: 2018-05-02
基金项目: 国家重点研发计划项目（2016YFF0203103-3）
作者简介:
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