Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis

Cr-segregation by spinodal decomposition and G-phase precipitation were observed in δ-ferrite of austenitic stainless steel welds thermally aged at 400 °C for up to 20,000 h. A reversion heat treatment (R-HT) at 550 °C for 1 h dissolved the Cr-segregation in the aged welds while some intermetallic p...

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Autores principales: Obulan Subramanian, Gokul, Kong, Byeong Seo, Lee, Ho Jung, Jang, Changheui
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6179992/
https://www.ncbi.nlm.nih.gov/pubmed/30305663
http://dx.doi.org/10.1038/s41598-018-33422-x
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author Obulan Subramanian, Gokul
Kong, Byeong Seo
Lee, Ho Jung
Jang, Changheui
author_facet Obulan Subramanian, Gokul
Kong, Byeong Seo
Lee, Ho Jung
Jang, Changheui
author_sort Obulan Subramanian, Gokul
collection PubMed
description Cr-segregation by spinodal decomposition and G-phase precipitation were observed in δ-ferrite of austenitic stainless steel welds thermally aged at 400 °C for up to 20,000 h. A reversion heat treatment (R-HT) at 550 °C for 1 h dissolved the Cr-segregation in the aged welds while some intermetallic precipitates were present. The double-loop electrochemical potentiokinetic reactivation (DL-EPR) analysis showed no significant differences among them. However, after selective etching of the austenite phase, the DL-EPR values of δ-ferrite phase steadily increased with aging time due to the growth of Cr-depleted regions by spinodal decomposition. The electrochemical behavior of δ-ferrite after R-HT condition was similar to that of unaged welds, indicating the intermetallic precipitates did not affect the corrosion resistance in this case. Overall, DL-EPR analysis of δ-ferrite phase provided better correlation with spinodal decomposition.
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spelling pubmed-61799922018-10-12 Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis Obulan Subramanian, Gokul Kong, Byeong Seo Lee, Ho Jung Jang, Changheui Sci Rep Article Cr-segregation by spinodal decomposition and G-phase precipitation were observed in δ-ferrite of austenitic stainless steel welds thermally aged at 400 °C for up to 20,000 h. A reversion heat treatment (R-HT) at 550 °C for 1 h dissolved the Cr-segregation in the aged welds while some intermetallic precipitates were present. The double-loop electrochemical potentiokinetic reactivation (DL-EPR) analysis showed no significant differences among them. However, after selective etching of the austenite phase, the DL-EPR values of δ-ferrite phase steadily increased with aging time due to the growth of Cr-depleted regions by spinodal decomposition. The electrochemical behavior of δ-ferrite after R-HT condition was similar to that of unaged welds, indicating the intermetallic precipitates did not affect the corrosion resistance in this case. Overall, DL-EPR analysis of δ-ferrite phase provided better correlation with spinodal decomposition. Nature Publishing Group UK 2018-10-10 /pmc/articles/PMC6179992/ /pubmed/30305663 http://dx.doi.org/10.1038/s41598-018-33422-x Text en © The Author(s) 2018 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Obulan Subramanian, Gokul
Kong, Byeong Seo
Lee, Ho Jung
Jang, Changheui
Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
title Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
title_full Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
title_fullStr Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
title_full_unstemmed Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
title_short Evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
title_sort evaluation of the thermal aging of δ-ferrite in austenitic stainless steel welds by electrochemical analysis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6179992/
https://www.ncbi.nlm.nih.gov/pubmed/30305663
http://dx.doi.org/10.1038/s41598-018-33422-x
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