Effect of severe plastic deformation on creep behaviour and microstructure changes of P92 at 923K

0546194 - ÚFM 2022 RIV SK eng J - Journal Article
Král, Petr - Dvořák, Jiří - Sklenička, Václav - Masuda, T. - Tang, Y. - Horita, Z. - Kunčická, Lenka - Kuchařová, Květa - Kvapilová, Marie - Svobodová, M.
Effect of severe plastic deformation on creep behaviour and microstructure changes of P92 at 923K.
Kovové materiály. ROČ. 59, č. 3 (2021), s. 141-148. ISSN 0023-432X. E-ISSN 1338-4252
R&D Projects: GA ČR(CZ) GA19-18725S
Institutional support: RVO:68081723
Keywords : creep-resistant 9% Cr steels * severe plastic deformation * creep
OECD category: Materials engineering
Impact factor: 0.690, year: 2021
Method of publishing: Open access
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The creep behaviour of P92 steel at 923 K, deformed by rotary swaging (RS) and high-pressure torsion (HPT), was investigated. The RS-processed state contained extremely inhomogeneous microstructure containing large elongated and fine, more or less equiaxed grains. By contrast, the HPT-processed state consists of homogeneous fine-grained microstructure. It was found that both the microstructures coarsen not only with the increasing creep time but also with creep strain. The creep strain significantly accelerates the coarsening of the microstructure, especially in the HPT-processed state. The grain coarsening during creep leads to the change of the creep rate stress exponent n thus to the change of creep mechanism. The value of n depends on the ratio grain versus stationary subgrain size. P92 steel processed by RS and HPT exhibited faster <(epsilon)over dot>(min) and higher ductility compared to coarse-grained (CG) state. However, RS-processed P92 steel can exhibit at high stresses similar creep behaviour as CG state.
Permanent Link: http://hdl.handle.net/11104/0322832