作者：张颖1, 吴昊1, 李彬1, 李栋山2
作者单位：1. 东北石油大学机械科学与工程学院, 黑龙江 大庆 163318;
2. 北京日泰科技有限公司, 北京 100012
关键词：非线性超声;基波;二次谐波;晶粒度;非线性系数
摘要：
传统的线性超声检测技术对微观缺陷的检测不敏感，而非线性超声检测是利用信号的频域特征来进行缺陷判别，具有独特的优势。采用RAM-5000 SNAP非线性超声检测系统，对不同晶粒度20#钢试件进行非线性超声检测实验。通过测量不同试件在相同激励条件下的基波与二次谐波幅值，得到其相关非线性系数，分析材料不同晶粒度对非线性超声特性的影响。结果表明：随着材料晶粒度的增大，超声非线性效应增强，非线性系数值不断增加。因此，利用非线性系数可以表征材料微观晶粒度的变化情况，验证非线性超声检测技术在判别材料微观组织变化中的有效性。
Experimental research on nonlinear ultrasonic characteristics of 20# steel specimens with different grain sizes
ZHANG Ying1, WU Hao1, LI Bin1, LI Dongshan2
1. College of Mechanical Science and Engineering, Northeast Petroleum University, Daqing 163318, China;
2. Beijing RITEC Technology Co., Ltd., Beijing 100012, China
Abstract: Conventional linear ultrasonic detection technique, as constrained by its rationale, is insensitive in microdefect detection; however, the nonlinear ultrasonic detection is of a unique advantage as it applies the characteristics in frequency domain of signal to differentiate defects. RAM-5000 SNAP nonlinear ultrasonic detection system is employed to carry out nonlinear ultrasonic detecting experiment on 20# steel test pieces with different grain sizes. By measuring the amplitudes of fundamental wave and second harmonics of different test pieces under the identical excitation conditions, associated nonlinear coefficients have been obtained and influences on nonlinear ultrasonic characteristics by different grain sizes of materials have been analyzed. Experimental results show that the enlarging of material grain size enhances the ultrasonic nonlinear effects, resulting in the continuous increase of nonlinear coefficient values. Therefore, taking use of the nonlinear coefficient enables the representation of the variation of material microscopic grain size, based on which the validity and effectiveness of nonlinear ultrasonic detection technique are verified in differentiating microstructure changes of materials.
Keywords: nonlinear ultrasonic;fundamental wave;second harmonic;grain size;nonlinear coefficient
2016, 42(8): 123-126 收稿日期: 2016-2-3;收到修改稿日期: 2016-4-11
基金项目: 黑龙江省博士后科研启动项目（LBH-Q14031）；东北石油大学研究生创新科研项目（YJSCX2015-025NEPU）
作者简介: 张颖(1972-),男,黑龙江大庆市人,教授,博士,主要从事过程设备安全检测及完整性评价的研究。
参考文献
[1] 周正干,刘斯明. 非线性无损检测技术的研究尧应用和发展[J]. 机械工程学报,2011,47(8):2-11.
[2] 耿荣生,景鹏. 基于声发射监测的综合无损检测技术与飞机疲劳试验定寿[J]. 应用声学,2011,31(1):28-34.
[3] 吴斌,颜丙生,李佳锐,等. 镁合金疲劳早期非线性超声在线检测实验研究[J]. 声学学报,2011,36(5):527-533.
[4] 颜丙生,吴斌,李佳锐,等. 金属材料力学性能退化非线性超声检测实验系统优化[J]. 仪表技术与传感器,2011(2):95-98.
[5] 陆铭慧,徐肖霞. 非线性超声检测方法及应用[J]. 无损检测,2012,34(7):61-66.
[6] 艾春安,蔡笑风,刘继方,等. 短时傅里叶变换声-超声检测信号缺陷识别[J]. 中国测试,2015,41(4):30-35.
[7] 周正干,刘斯明. 铝合金初期塑性变形与疲劳损伤的非线性超声无损评价方法[J].机械工程学报,2011,47(8):41-46.
[8] 税国双,汪越胜,曲建民. 材料力学性能退化的超声无损检测与评价[J]. 力学进展,2005,35(1):52-68.
[9] 贺西平,田彦平,张宏普. 超声无损评价金属材料晶粒尺寸的研究[J]. 声学技术,2013,32(6):445-450.
[10] 吴斌,颜丙生,何存富,等. AZ31镁合金早期力学性能退化非线性超声检测[J]. 航空材料学报,2011,31(1):87-92.
[11] NAGY P B. Fatigue damage assessment by nonlinear ultrasonic materials characterization[J]. Ultrasonics,1998(36):375-381.
[12] CANTRELL L H,YOST W T. Nonlinear ultrasonic characterization of fatigue microstructures[J]. International Journal of Fatigue,2001(23):487-490.
[13] KIM J Y,JACOBS L J,QU J,et al. Experimental characterization of fatigue damage in a nickel-base superalloy using nonlinear ultrasonic waves[J]. Journal of the Acoustical Society of America,2006,120(3):1266-1273.
