Session: NDE-03-01 NDE Reliability-Modeling and Experimental Analysis

Paper Number: 122966

122966 - Numerical and Experimental Study of Detection of Linear Damage of Pressure Equipment Using Electromagnetic Acoustic Resonant Method 

The pressure equipment is long-term serviced in harsh environments such as high temperature and strong corrosion, which is prone to linear damage such as corrosion thinning, delamination and cracking. Due to the necessity of coupling agent and surface pretreatment, the contact ultrasonic testing method is difficult to applied to the non-grinding detection of pressure equipment with corrosion layer or under high temperature. Electromagnetic acoustic testing method has the advantages of non-contact and no coupling agent. However, the improvement of detection accuracy is restricted by the low energy conversion efficiency and time domain signal distortion at high temperature restrict. Acoustic resonance is an analysis technique of frequency domain that uses a broadband signal to excite the transducer to obtain the resonance information of the test samples, which can effectively improve the echo energy intensity. In this paper, the electromagnetic acoustic resonance (EMAR) testing model is established based on the mechanism of magnetic-electric-force-acoustic energy conversion. A magnetically concentrated electromagnetic acoustic resonant transducer is designed further. The flat-bottom holes and rectangular grooves are used to simulate the linear damage of the test samples. Then, the electromagnetic sound field distribution and time-frequency domain response characteristics of different damages are studied. The correlation between the local corrosion detection ability and the transducer size is clarified. A testing system of the electromagnetic acoustic resonance is designed and developed. The series of experiments including thickness measurement of step plate in high temperature and the flat bottom holes detection are carried out. The results show that the electromagnetic acoustic resonance testing system under broadband pulse excitation can achieve accurate measurement of wall thickness variation with an error of less than 1 %. the relationship between local corrosion defects and transducer size is verified. The measurement of wall thickness at 500℃ is realized and the error is within ±0.1 mm. The studies lay a foundation for the quantitative detection and monitoring of linear damage of pressure equipment with corrosion layer or under high temperature.

Presenting Author: Zhe Wang Hefei General Machinery Research Institute Co., Ltd

Presenting Author Biography: Zhe Wang, born in 1991, is currently an assistant research fellow at Hefei General Machinery Research Institute Co., Ltd, China. He received his BSc and Phd from School of Mechanical Science & Engineering at Huazhong University of Science and Technology, China, in 2013 and 2019, respectively. His research interests include nondestructive testing technology and instrumentation development, such as piezoelectric/electromagnetic ultrasonic inspection.

Authors:

Zhe Wang Hefei General Machinery Research Institute Co., Ltd
Zhichao Fan Hefei General Machinery Research Institute Co., Ltd
Jian Tang Hefei General Machinery Research Institute Co., Ltd
Jingwei Cheng Hefei General Machinery Research Institute Co., Ltd
Tian Ji Hefei General Machinery Research Institute Co., Ltd
Haibin Wang Hefei General Machinery Research Institute Co., Ltd
Yangguang Bu Hefei General Machinery Research Institute Co., Ltd