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Investigating the thermal stability of compressive residual stress in a gradient nanostructured austenitic stainless steel by in-situ XRD and TEM.

Authors :
He, Yinsheng
Zhou, Hongyu
Zhao, Yuchen
Zhang, Tao
Liu, Chunjie
Xu, Liming
Shin, Keesam
Zheng, Wenyue
Source :
Materials Characterization. Jan2024, Vol. 207, pN.PAG-N.PAG. 1p.
Publication Year :
2024

Abstract

A widely used approach for extending the fatigue life of engineering steels is through the introduction of compressive residual stress (CRS). The thermal stabilities of the introduced residual stress may determine their effectiveness in high-temperature application, which had been extensively studied by ex-situ technology in the past two decades. Here, the in-situ heating techniques of synchrotron XRD, XRD and TEM were used to study the evolution of CRS and corresponding microstructural evolution in a gradient nanostructured (GNS) austenitic stainless steel. As the temperature increased upto 500 °C, the magnitude of CRS decreased continuously by 63% when the phase composed of 100% strain-induced α'-martensite in the GNS layer, while it was decreased by 23% in the dual-phases composed of 60% α' and 40% γ. This result was attributed to the fact that the CRS introduced by the α'-martensite belongs to the type III micro-stress and was stored in the dislocations, which shows a high recovery trend upon heating. However, the CRS in the dual-phase structures is the type II intergranular stress, which is relatively stable upon heating. The current work suggested the importance of α'-martensite on the stabilizing of CRS, which may guide the materials design for high-temperature application. • Thermal stability of RS in GNS steel was investigated by in-situ XRD and TEM. • RS relaxation in single α' phase material is higher than the dual-phase of α' + γ. • Compressive RS of the dual-phase (60%α' + 40%γ) is stable upon heating. • RS relaxation in 100% α'-bcc attributed to the dislocation annihilation at 500 °C. • The stable of RS in dual-phase is due to the stable phases at 500 °C. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
10445803
Volume :
207
Database :
Academic Search Index
Journal :
Materials Characterization
Publication Type :
Academic Journal
Accession number :
174605963
Full Text :
https://doi.org/10.1016/j.matchar.2023.113610