Effect of machining on near surface microstructure and the observation of martensite at the fatigue crack tip in PWR environment of 304L stainless steel
Year of publication
2022
Authors
Que, Zaiqing; Huotilainen, Caitlin; Seppänen, Tiia; Lydman, Jari; Ehrnstén, Ulla
Abstract
This work highlighted that a ground surface finish and the exposure to a pressurised water reactor (PWR) environment result in a decreased low-cycle fatigue lifetime, an enhanced fatigue crack initiation and an accelerated fatigue crack growth rate of 304 L austenitic stainless steel. A ground surface finish promotes fatigue crack initiation and short crack growth especially in a water environment, due to the highly deformed underlying microstructure with high-angle grain boundaries and the grinding marks on surface. Martensite was observed in the vicinity of secondary crack tips in specimens tested in a simulated PWR primary side environment. The aggregated presence of α′- and ε-martensite in the vicinity of the fatigue crack tip can enhance the material's susceptibility to hydrogen-assisted fatigue cracking. Martensite formation was rarely observed in specimens exposed to high temperature air. The phase transformation from γ-austenite to αꞌ-martensite in the PWR primary environment occurred via the intermediate ε-martensite phase.
Show moreOrganizations and authors
Publication type
Publication format
Article
Parent publication type
Journal
Article type
Original article
Audience
ScientificPeer-reviewed
Peer-ReviewedMINEDU's publication type classification code
A1 Journal article (refereed), original researchPublication channel information
Journal
Volume
558
Article number
153399
ISSN
Publication forum
Publication forum level
2
Open access
Open access in the publisher’s service
Yes
Open access of publication channel
Partially open publication channel
License of the publisher’s version
CC BY
Self-archived
No
Other information
Fields of science
Physical sciences; Materials engineering
Keywords
[object Object],[object Object],[object Object],[object Object],[object Object]
Language
English
International co-publication
No
Co-publication with a company
No
DOI
10.1016/j.jnucmat.2021.153399
The publication is included in the Ministry of Education and Culture’s Publication data collection
Yes