Detection of Stress Corrosion Cracking in SS304 under Calcium Silicate Thermal Insulation Using Acoustic Emission Technique

Abstract:

Despite its remarkable structural strength, austenitic stainless steels such as SS304 are susceptible to stress corrosion cracking (SCC) under thermal insulation due to the synergism of cyclic loading and chloride-containing environments. This study aims to detect SCC for insulated SS304 samples using the acoustic emission technique (AET) as monitoring tool to characterize the various stages of SCC damage mechanism. As-received (AR) and sensitized (SEN) SS304 samples were prepared as per ASTM G30 and experimented with soluble chloride drip test under calcium silicate thermal insulation following ASTM C692. Both AR and SEN samples revealed SCC behavior correlated with measured acoustic signals. AR samples exhibited a single crack with low energetic signals, whereas SEN showed multiple cracks with higher energetic signal events. The difference can be attributed to microstructure change by heat sensitization and the enhancement of the corrosion environment under calcium silicate insulation when wetted by salt solution. The acoustic emission (AE) parameters were characterized and correlated with different stages of SCC phenomena, showing that AET is useful for predicting SCC to avoid catastrophic failures in industries.

• Periodical: Materials Science Forum (Volume 1139)
• Pages: 33-40
• DOI: https://doi.org/10.4028/p-uQ9RGA
• Online since: December 2024
• Authors: Suresh Nuthalapati, Kok Eng Kee*, Mokhtar Che Ismail, Supat Ieamsupapong
• Keywords: Acoustic Emission Technique, Calcium Silicate Thermal Insulation, SS304, Stress Corrosion Cracking

References

[1] T. Michler, "Austenitic Stainless Steels," in Reference Module in Materials Science and Materials Engineering, no. June 2015, Elsevier, 2016, p.1–6.

DOI: 10.1016/B978-0-12-803581-8.02509-1

[2] S. Nuthalapati, K. E. Kee, S. R. Pedapati, and K. Jumbri, "A review of chloride induced stress corrosion cracking characterization in austenitic stainless steels using acoustic emission technique," Nucl. Eng. Technol., vol. 56, no. 2, p.688–706, Feb. 2024.

DOI: 10.1016/j.net.2023.11.005

[3] "Design for the prevention of corrosion-under-insulation," in Corrosion Under Insulation (CUI) Guidelines, Elsevier, 2020, p.67–76.

DOI: 10.1016/B978-0-12-823332-0.00008-8

[4] N. Wilds, "Corrosion under insulation," in Trends in Oil and Gas Corrosion Research and Technologies, Elsevier, 2017, p.409–429.

DOI: 10.1016/B978-0-08-101105-8.00017-6

[5] X. Yang et al., "Microstructure and Mechanical Properties of an Austenitic Heat-Resistant Steel after Service at 570 °C and 25.4 MPa for 18 Years," J. Mater. Eng. Perform., vol. 30, no. 2, p.1030–1038, 2021.

DOI: 10.1007/s11665-020-05420-6

[6] P. Roffey and E. H. Davies, "The generation of corrosion under insulation and stress corrosion cracking due to sulphide stress cracking in an austenitic stainless steel hydrocarbon gas pipeline," Eng. Fail. Anal., vol. 44, p.148–157, Sep. 2014.

DOI: 10.1016/j.engfailanal.2014.05.004

[7] X. Li et al., "Characteristic of Acoustic Emission Signal from Stress Corrosion Cracking in Low-Carbon Nitrogen-Enhanced Stainless Steel," Sensors Mater., vol. 29, no. 9, p.1305, 2017.

DOI: 10.18494/SAM.2017.1604

[8] L. Calabrese and E. Proverbio, "A Review on the Applications of Acoustic Emission Technique in the Study of Stress Corrosion Cracking," Corros. Mater. Degrad., vol. 2, no. 1, p.1–33, Dec. 2020.

DOI: 10.3390/cmd2010001

[9] A. Terchi and Y. H. J. Au, "Acoustic Emission Signal Processing," Meas. Control, vol. 34, no. 8, p.240–244, Oct. 2001.

DOI: 10.1177/002029400103400804

[10] Q. Cao et al., "A Review of Corrosion under Insulation: A Critical Issue in the Oil and Gas Industry," Metals (Basel)., vol. 12, no. 4, p.1–24, 2022.

DOI: 10.3390/met12040561

[11] H. Cho, Y. Tamura, and T. Matsuo, "Monitoring of Corrosion Under Insulations by Acoustic Emission and Humidity Measurement," J. Nondestruct. Eval., vol. 30, no. 2, p.59–63, Jun. 2011.

DOI: 10.1007/s10921-011-0090-z