Comparative Study of Acoustic Emission Characteristics for Intergranular Corrosion of 316L Stainless Steel Parent Material and Weldment

2014 ◽  
Author(s):  
Wenjie Bai ◽  
Mengyu Chai ◽  
Lichan Li ◽  
Quan Duan
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Comparative Analysis ◽  
Intergranular Corrosion ◽  
316L Stainless Steel ◽  
Signal Amplitude ◽  
Parent Material ◽  
Ae Signal ◽  
Preliminary Corrosion ◽  
Spectrum Characteristics

The 316L stainless steel parent material and weldment specimens were made to carry out intergranular corrosion(IGC) test using the method of boiling nitric acid. During the corrosion experiment, the acoustic emission(AE) signals were collected. Through the comparative analysis of corrosion rate and metallographic structure, the results showed that the IGC of parent material and weldment can be divided into the preliminary corrosion stage and the rapid corrosion stage. The AE parameters and spectrum characteristics of the two corrosion stages of the parent material and weldment were analyzed. The results showed that: in preliminary and rapid corrosion stages, the AE signal amplitude and energy of weldment were higher than that of parent material; the spectrum characteristics of weldment was more abundant than that of parent material. Based on the results of the comparative analysis, the AE sources of parent material and weldment IGC and the possibilities of monitoring IGC using AE technique were analyzed.

scholarly journals Identification of fatigue damage evolution in 316L stainless steel using acoustic emission and digital image correlation

2018 ◽  
Vol 165 ◽  
pp. 22007 ◽  
Author(s):  
Farhan Tanvir ◽  
Tariq Sattar ◽  
David Mba ◽  
Graham Edwards ◽  
Elvin Eren ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Digital Image Correlation ◽  
Digital Image ◽  
316L Stainless Steel ◽  
Signal Amplitude ◽  
Image Correlation ◽  
Effective Measure ◽  
Time Domain Signal ◽  
Renyi’S Entropy

One of the main objectives of Acoustic Emission (AE) monitoring is to identify approaching critical stage of damage in the structure before it fails. State-of-the-art AE analysis is done on the features in both the time and frequency domains. Many features such as centroid frequency, duration, rise-time, count and energy are dependent on acquisition settings; threshold and timing parameters. Incorrect acquisition settings may result in inaccurate classification of the AE source. This work proposes a new feature in the time domain signal based on 2nd order Renyi’s entropy, which proves to be efficient in identifying different stages of damage. Renyi’s entropy is a measure of uncertainty or randomness of the signals and is directly derived from the distribution of signal amplitude. Therefore, it is independent of threshold and timing parameters. The validity of the proposed parameter is investigated by performing AE monitoring during fatigue endurance test of 316L stainless steel. Digital Image Correlation (DIC) and global strain monitoring was carried out to relate material damage with AE activity. The result shows Renyi’s entropy to be an effective measure to identify critical stages of damage in the material.

scholarly journals Analysis of Acoustic Emission (AE) Signals for Quality Monitoring of Laser Lap Microwelding

2021 ◽  
Vol 11 (15) ◽  
pp. 7045
Author(s):  
Ming-Chyuan Lu ◽  
Shean-Juinn Chiou ◽  
Bo-Si Kuo ◽  
Ming-Zong Chen
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Frequency Domain ◽  
Monitoring System ◽  
Welding Quality ◽  
Steel Sheets ◽  
Signal Features ◽  
Ae Signal ◽  
Laser Microwelding ◽  
Ae Signals

In this study, the correlation between welding quality and features of acoustic emission (AE) signals collected during laser microwelding of stainless-steel sheets was analyzed. The performance of selected AE features for detecting low joint bonding strength was tested using a developed monitoring system. To obtain the AE signal for analysis and develop the monitoring system, lap welding experiments were conducted on a laser microwelding platform with an attached AE sensor. A gap between the two layers of stainless-steel sheets was simulated using clamp force, a pressing bar, and a thin piece of paper. After the collection of raw signals from the AE sensor, the correlations of welding quality with the time and frequency domain features of the AE signals were analyzed by segmenting the signals into ten 1 ms intervals. After selection of appropriate AE signal features based on a scatter index, a hidden Markov model (HMM) classifier was employed to evaluate the performance of the selected features. Three AE signal features, namely the root mean square (RMS) of the AE signal, gradient of the first 1 ms of AE signals, and 300 kHz frequency feature, were closely related to the quality variation caused by the gap between the two layers of stainless-steel sheets. Classification accuracy of 100% was obtained using the HMM classifier with the gradient of the signal from the first 1 ms interval and with the combination of the 300 kHz frequency domain signal and the RMS of the signal from the first 1 ms interval.

Precipitation formation on ∑5 and ∑7 grain boundaries in 316L stainless steel and their roles on intergranular corrosion

2021 ◽  
pp. 116822
Author(s):  
Shao-Pu Tsai ◽  
Surendra Kumar Makineni ◽  
Baptiste Gault ◽  
Kaori Kawano-Miyata ◽  
Akira Taniyama ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Intergranular Corrosion ◽  
316L Stainless Steel ◽  
Precipitation Formation

Acoustic Emission Analysis of Nanoindentation-Induced Fracture Events

2004 ◽  
Vol 841 ◽  
Author(s):  
Pawel Dyjak ◽  
Raman P. Singh
Keyword(s):  
Acoustic Emission ◽  
Brittle Materials ◽  
Signal Amplitude ◽  
Crack Arrest ◽  
Quantitative Information ◽  
Local Failure ◽  
Emission Analysis ◽  
Specimen Holder ◽  
Cube Corner ◽  
Ae Signal

ABSTRACTMonitoring of acoustic emission (AE) activity was employed to characterize the initiation and progression of local failure processes during nanoindentation-induced fracture. Specimens of various brittle materials were loaded with a cube-corner indenter and AE activity was monitored during the entire loading and unloading event using an AE transducer mounted inside the specimen holder. As observed from the nanoindentation and AE response, there were fundamental differences in the fracture behavior of the various materials. Post-failure observations were used to identify particular features in the AE signal (amplitude, frequency, rise-time) that correspond to specific types of fracture events. Furthermore, analysis of the parametric and transient AE data was used to establish the crack-initiation threshold, crack-arrest threshold, and energy dissipation during failure. It was demonstrated that the monitoring of AE signals yields both qualitative and quantitative information regarding highly local failure events in brittle materials.

scholarly journals Monitoring of Changes Signal Acoustic Emission Signals Using Waveguides

2017 ◽  
Vol 65 (4) ◽  
pp. 1317-1322 ◽  
Author(s):  
Jaroslav Začal ◽  
Petr Dostál ◽  
Michal Šustr ◽  
David Dobrocký
Keyword(s):  
Experimental Study ◽  
Stainless Steel ◽  
Acoustic Emission ◽  
Signal Detection ◽  
Piezoelectric Sensors ◽  
Material Surface ◽  
Medium Density ◽  
Medium Density Fibreboard ◽  
Ae Signal ◽  
Signal Dampening

This paper is focused on possibilities of acoustic emission (AE) signal detection from material surface through waveguide for commonly used piezoelectric sensors. It also considers the experimental study of enhanced detection of occurrence of signal guided through waveguide corpus, its changes and deformities. Aim of this work is verification of several waveguide setup possibilities for maximization of AE signal detection in practice. For this purpose, multiple waveguide setups were manufactured from stainless steel and aluminium alloy. Hsu‑Nielson pen test was utilized for signal actuation. Results demonstrate the differences between measured AE signal with and without employment of waveguide (changes in signal course through different materials and shapes), as well as magnitude of signal dampening and amplification necessary for veritable signal interpretation. Measurements were conducted on agglomerated composite of medium density fibreboard (MDF).

The Effect of Sigma Phase vs Chromium Carbides On the Intergranular Corrosion Of Type 316 and 316L Stainless Steel (Part 2—Laboratory Investigation)★

CORROSION ◽  
1959 ◽  
Vol 15 (5) ◽  
pp. 17-28 ◽  
Author(s):  
DONALD WARREN
Keyword(s):  
Stainless Steel ◽  
Intergranular Corrosion ◽  
Sigma Phase ◽  
316L Stainless Steel ◽  
Steel Part ◽  
Intergranular Attack ◽  
Acid Media ◽  
Chromium Carbides ◽  
Type 316L ◽  
Stainless Steel Part

Abstract A laboratory study was made of the intergranular corrosion behavior of Types 316 and 316L stainless steel in 14 different acid environments. Included were nitric, nitric-hydrofluoric, acetic, citric, sulfuric, lactic, oxalic, formic and phosphoric acids. Results of this study showed that sensitized or welded Type 316L had excellent resistance to intergranular attack in all of the acid media except nitric. This was true despite the presence of a continuous network of sigma phase in the grain boundaries of the sensitized steel. In contrast, Type 316 having a continuous grain boundary network of chromium carbides underwent severe intergranular corrosion in 12 of the 14 environments studied. 3.2.2

Investigation on Acoustic Emission Characteristics from Corrosion of Conventional Materials of Primary Pipe in Nuclear Power Plants

2014 ◽  
Vol 487 ◽  
pp. 54-57 ◽  
Author(s):  
Meng Yu Chai ◽  
Li Chan Li ◽  
Wen Jie Bai ◽  
Quan Duan
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Pitting Corrosion ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
316L Stainless Steel ◽  
304 Stainless Steel ◽  
Emission Characteristics ◽  
Research Topics

304 stainless steel and 316L stainless steel are conventional materials of primary pipeline in nuclear power plants. The present work is to summarize the acoustic emission (AE) characteristics in the process of pitting corrosion of 304 stainless steel, intergranular corrosion of 316L stainless steel and weldments of 316L stainless steel. The work also discussed the current shortcomings and problems of research. At last we proposed the coming possible research topics and directions.

Mechanism of intergranular corrosion of 316L stainless steel in oxidizing acids

1980 ◽  
Vol 14 (11) ◽  
pp. 1175-1179 ◽  
Author(s):  
T.M. Devine ◽  
C.L. Briant ◽  
B.J. Drummond
Keyword(s):  
Stainless Steel ◽  
Intergranular Corrosion ◽  
316L Stainless Steel
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