scholarly journals Evaluation of Microscopic Damage to TIG Welded Carbon Steel using Acoustic Emission and Ultrasonic Test

2012 ◽  
Vol 26 (5) ◽  
pp. 5-10
Author(s):  
Joon-Hyun Lee ◽  
Jin-Kyung Lee
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Ultrasonic Test ◽  
Microscopic Damage

An Evaluation on Corrosion Effect of Carbon Steel Using the NDT

2007 ◽  
Vol 353-358 ◽  
pp. 2411-2414
Author(s):  
Sang Ll Lee ◽  
Jin Kyung Lee ◽  
Joon Hyun Lee
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Power Plant ◽  
Failure Mechanism ◽  
Attenuation Factor ◽  
Ultrasonic Test ◽  
Carbon Steels ◽  
Secondary Circuit ◽  
Acoustic Emission Technique ◽  
Corrosion Effect

The nuclear power plant has lots of pipes that the fluid of high temperature and high pressure flows. Among the pipe materials used at secondary circuit of the power plant the carbon steels are sensitive to corrosion due to their material properties. In this study, both ultrasonic test and acoustic emission test were used to study the corrosion effect for the carbon steel pipe nondestructively. The carbon steel specimens were in the pipe under 473K temperatures and 10MPa pressure conditions for corrosion processing. According to the degree of corrosion the strength of the specimen was evaluated, and the thickness of the corrosion specimens was also measured by using the ultrasonic wave. The experimental results showed that the attenuation factor was also increased as a depth of corrosion increased. The measured depth of the real corrosion by ultrasonic test shows the good agreement with that by an optical microscope. In order to understand the corrosion effect for the failure mechanism of carbon steel, a failure test on the specimen with various corrosion conditions was performed. An acoustic emission technique was also used to evaluate the degree of damage of corrosion specimen in real time. Acoustic emission technique is proved a useful method for on-line monitoring the microscopic failure mechanism and the damage location for the structures.

scholarly journals In-Situ Monitoring and Analysis of the Pitting Corrosion of Carbon Steel by Acoustic Emission

2019 ◽  
Vol 9 (4) ◽  
pp. 706 ◽  
Author(s):  
Junlei Tang ◽  
Junyang Li ◽  
Hu Wang ◽  
Yingying Wang ◽  
Geng Chen
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Pitting Corrosion ◽  
Optical Microscope ◽  
Open Circuit ◽  
In Situ Monitoring ◽  
Localized Corrosion ◽  
Uniform Corrosion ◽  
Corrosion Morphology

The acoustic emission (AE) technique was applied to monitor the pitting corrosion of carbon steel in NaHCO3 + NaCl solutions. The open circuit potential (OCP) measurement and corrosion morphology in-situ capturing using an optical microscope were conducted during AE monitoring. The corrosion micromorphology was characterized with a scanning electron microscope (SEM). The propagation behavior and AE features of natural pitting on carbon steel were investigated. After completion of the signal processing, including pre-treatment, shape preserving interpolation, and denoising, for raw AE waveforms, three types of AE signals were classified in the correlation diagrams of the new waveform parameters. Finally, a 2D pattern recognition method was established to calculate the similarity of different continuous AE graphics, which is quite effective to distinguish the localized corrosion from uniform corrosion.

Feature Extraction of the Acoustic Emission Signals of Low Carbon Steel Pitting Corrosion Based on Independent Component Analysis and Wavelet Transform

2013 ◽  
Vol 373-375 ◽  
pp. 677-680
Author(s):  
Wei Li ◽  
Yu Li Gong ◽  
Yang Yu
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Independent Component Analysis ◽  
Pitting Corrosion ◽  
Wavelet Transformation ◽  
Low Carbon Steel ◽  
Component Analysis ◽  
Independent Component ◽  
Low Carbon ◽  
Ae Signals

Based on the characteristics of the acoustic emission (AE) signals from low carbon steel pitting corrosion, a new extraction method was proposed with wavelet transformation and independent component analysis. The experiment result shows that the new method can overcome the influence induced by the uncertainty of the independent source of low carbon steel pitting corrosion and good extraction result can be achieved.

Study on Damage Mechanism of Pipe Using Ultrasonic Wave and Acoustic Emission Technique

2007 ◽  
Vol 353-358 ◽  
pp. 2415-2418
Author(s):  
Jin Kyung Lee ◽  
Sang Ll Lee ◽  
Joon Hyun Lee
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Ultrasonic Wave ◽  
Guided Waves ◽  
Damage Mechanism ◽  
Ultrasonic Waves ◽  
Steel Pipe ◽  
Thin Wall ◽  
Acoustic Emission Technique ◽  
Velocity Transmission

A study on corrosion evaluation by using ultrasonic waves and acoustic emission technique is presented. The experimental equipment was established to improve the corrosion process of carbon steel pipe. The carbon steel pipe was under 473K temperatures and 10Mpa pressure conditions, and ultrasonic wave and acoustic emission techniques were used to inspect the degree of corrosion after a certain period of time. Ultrasonic bulk waves are limited by the poor time resolution when used in the measurement of corrosion depth in thin wall structures because the corroded surfaces cause unclear echo signal edges. Therefore, in this study, the ultrasonic guided waves were generated on the pipe because the thickness of pipe was thin. Various wave modes were subsequently generated on the pipe to evaluate the implications of corrosion thinning on group velocity, transmission and reflection amplitudes. The amplitudes of the transmitted and the reflected waves are influenced by couplent material. In order to reduce the effect of coupling acoustic emission sensor was used. Acoustic emission technique has lots of parameters to evaluate the corrosion besides amplitude parameter. Among parameters energy, count, and frequency were useful parameters to measure the degree of corrosion inside the carbon steel pipe under 473K temperatures.

Cluster Analysis of Acoustic Emission Signals During Carbon Steel Pitting Corrosion Process

2014 ◽  
Author(s):  
Zhongzheng Zhang ◽  
Cheng Ye ◽  
Jun Jiang
Keyword(s):  
Cluster Analysis ◽  
Acoustic Emission ◽  
Carbon Steel ◽  
Ferric Chloride ◽  
Pitting Corrosion ◽  
Chloride Solution ◽  
Ferric Chloride Solution ◽  
Corrosion Process ◽  
Different Types ◽  
Ae Signals

In order to study acoustic emission (AE) signals characteristics of pitting corrosion on carbon steel, Pitting corrosion process on carbon steel in 6% ferric chloride solution was monitored by AE technology. K-mean cluster algorithm was used to classify the monitored AE signals, in which the duration, counts, amplitude, absolute energy and peak frequency were analyzed as the AE signals characteristics, and different types AE sources were identified. The results showed that there were mainly three type AE sources during carbon steel pitting corrosion process in ferric chloride solution, and the different types AE sources could be classified by cluster analysis. The research results have some certain significance for AE monitoring of pitting corrosion on carbon steel.

Damage Evaluation on Torsion Fretting Fatigue Behavior of Low Alloy Carbon Steel using Acoustic Emission

2019 ◽  
Vol 2019 (0) ◽  
pp. J02338P
Author(s):  
Abhinav YADAV ◽  
Sarita MORAKUL ◽  
Yuichi OTSUKA ◽  
Kouhei Kaigaishi ◽  
Keisuke Okita ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Carbon Steel ◽  
Fatigue Behavior ◽  
Fretting Fatigue ◽  
Damage Evaluation ◽  
Alloy Carbon

Damage Pattern Recognition of Refractory Materials Based on k-Means Clustering Analysis

2012 ◽  
Vol 602-604 ◽  
pp. 990-994
Author(s):  
Xi Li ◽  
Zhi Gang Wang ◽  
Chang Ming Liu ◽  
Bing Qiang Han
Keyword(s):  
Pattern Recognition ◽  
Acoustic Emission ◽  
Clustering Analysis ◽  
Bending Test ◽  
Refractory Materials ◽  
Damage Pattern ◽  
Three Point Bending ◽  
Centroid Frequency ◽  
Acquisition Device ◽  
Microscopic Damage

The k-means algorithm was used to divide the acoustic emission signals collected during the three-point bending test into two types. Combining with the analysis of AE parameters can we distinguish the micro-damage pattern recognition of the refractory materials. The bending test equipment is HMOR/STRAIN, and the AE acquisition device is DISP from PAC. Amplitude, counts, risetime, duration and centroid frequency were selected as the AE parameters .The microscopic damage modes of the refractory materials were recognized.

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