Analysis of the elevated temperature deformation mechanisms and grain boundary strengthening of the alumina-forming austenitic stainless steel Fe-20Cr-30Ni-2Nb-5Al

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:814

Article

Peterson, Andrew¹  Baker, Ian¹ 

[1] Dartmouth Coll, Thayer Sch Engn, Hanover, NH 03755 USA

关键词: AFA steel;    Deformation;    Creep;    Precipitates;    Grain boundary;   

DOI  :  10.1016/j.msea.2021.141219

来源: Elsevier

【 摘 要 】

The deformation mechanisms of an alumina-forming austenitic stainless-steel Fe?20Cr?30Ni?2Nb?5Al (at. %) were investigated at 750 ?C using both creep tests and strain rate jump tests. It was found that nano-sized L12structured precipitates were the dominant precipitate in the matrix and provided the majority of the strengthening. This behavior could be modeled well using a threshold stress term in a power law creep equation. Additionally, there appears to be a grain boundary strengthening mechanism in which the grain boundaries covered by precipitates act as barriers to dislocation movement. This could be again modeled using a power law creep equation. In addition to blocking dislocations, the grain boundary precipitates also prevent grain boundary sliding during creep. While the grain boundaries showed several strengthening mechanisms, all tests ultimately failed along the grain boundaries.

【 授权许可】

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