Electrochemical characteristics of delta ferrite in thermally aged austenitic stainless steel weld

Gokul Obulan Subramanian, Sunghoon Hong, Ho Jung Lee, Byeong Seo Kong, Kyoung Soo Lee, Thak Sang Byun, Changheui Jang

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

An austenitic stainless steel Type 316L weld was thermally aged for 20,000 h at 400 °C and electrochemical characterization was performed to measure corrosion resistance in δ–ferrite phase. It is well known that a severe thermal aging causes decrease of fracture resistance and increase of the hardness of δ–ferrite, which was related to the spinodal decomposition. After thermal aging, the DL-EPR response of 316L weld was dominated by parent austenite matrix without reactivation peak. To characterize the δ–ferrite only, austenite phase was selectively dissolved from the matrix by electrochemical etching method. The double–loop electrochemical potentiokinetic reactivation (DL-EPR) analysis of the δ–ferrite phase showed degradation in corrosion resistance after thermal aging with the appearance of a cathodic loop and reactivation peak during the reverse scan. The degradation in corrosion resistance of δ–ferrite phase could be attributed to the localized Cr-depletion due to spinodal decomposition and precipitation of intermetallic phases during thermal aging.

Original languageEnglish
Title of host publicationMinerals, Metals and Materials Series
PublisherSpringer
Pages1869-1877
Number of pages9
ISBN (Print)9783030046385, 9783030046392, 9783319515403, 9783319651354, 9783319728520, 9783319950211
DOIs
Publication statusPublished - 2019
Event18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors 2019 - Boston, United States
Duration: 18 Aug 201922 Aug 2019

Publication series

NameMinerals, Metals and Materials Series
ISSN (Print)2367-1181
ISSN (Electronic)2367-1696

Conference

Conference18th International Conference on Environmental Degradation of Materials in Nuclear Power Systems – Water Reactors 2019
Country/TerritoryUnited States
CityBoston
Period18/08/1922/08/19

Bibliographical note

Funding Information:
This study is mainly supported by the Korea Hydro and Nuclear Power Co., Ltd. as the Proactive Material Aging Management Project. Part of the funding is provided as Nuclear R&D Program (2015M2A8A2074798) of the MSIP/NRF of Rep. of Korea. Financial support for three of the authors is provided by the BK-Plus Program of the MSIP of Rep. of Korea.

Publisher Copyright:
© 2019, The Minerals, Metals & Materials Society.

Keywords

  • Corrosion
  • Delta ferrite
  • DL-EPR analysis
  • Stainless steel weld
  • Thermal aging

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy Engineering and Power Technology
  • Mechanics of Materials
  • Metals and Alloys
  • Materials Chemistry

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