Fatigue oligocyclique d'un acier inoxydable austénitique 304L : influence de l'état de surface et de signaux de chargement en milieu eau primaire REP

Abstract : The fatigue design of Pressurized Water Reactor (PWR) components takes into account many parameters suchas the surface finish, the scale effects, the material variability, etc. To optimise this design, it is necessary tounderstand the role of those parameters and to identify their possible interactions with PWR waterenvironment.This work is focused on the low cycle fatigue behaviour of a 304L austenitic stainless steel in threeenvironments, namely vacuum, air and PWR water, through fatigue lifetimes, cracking mechanisms and crackgrowth characterisations. In addition, the roles of both surface finish (polished or ground) and load signal form(triangular signals with different strain rates or complex signals representative of successive thermal shocks)were investigated.The PWR water environment causes a fatigue life reduction and a crack propagation rate enhancement,regardless of surface finish or load signal shape. The deleterious effect of ground surface finish observed onfatigue life is explained by means of interrupted tests through qualitative and quantitative damage analysis. Theimportance of the crack geometry is revealed by fractographic characterisations and its integration inpropagation laws is used to account for fatigue life reductions induced by ground surface finish. Finally thesignal shape effects on cyclic behaviour, damage kinetics and fatigue life are discussed. The influence of theposition of the low strain rate parts within a complex cycle is analysed taking into account the time of crackexposure to the environment.
Document type :
Theses
Complete list of metadatas

Cited literature [105 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-01245651
Contributor : Abes Star <>
Submitted on : Thursday, December 17, 2015 - 2:52:06 PM
Last modification on : Tuesday, June 4, 2019 - 6:22:02 PM
Long-term archiving on : Friday, March 18, 2016 - 1:40:19 PM

File

2015ESMA0011_poulain.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01245651, version 1

Collections

Citation

Thibault Poulain. Fatigue oligocyclique d'un acier inoxydable austénitique 304L : influence de l'état de surface et de signaux de chargement en milieu eau primaire REP. Autre. ISAE-ENSMA Ecole Nationale Supérieure de Mécanique et d'Aérotechique - Poitiers, 2015. Français. ⟨NNT : 2015ESMA0011⟩. ⟨tel-01245651⟩

Share

Metrics

Record views

380

Files downloads

549