Effects of Grain Refinement and Predeformation Impact by Severe Plastic Deformation on Creep in P92 Martensitic Steel

0511810 - ÚFM 2023 RIV DE eng J - Journal Article
Sklenička, Václav - Král, Petr - Dvořák, Jiří - Takizawa, Y. - Masuda, T. - Horita, Z. - Kuchařová, Květa - Kvapilová, Marie - Svobodová, M.
Effects of Grain Refinement and Predeformation Impact by Severe Plastic Deformation on Creep in P92 Martensitic Steel.
Advanced Engineering Materials. Roč. 22, č. 1 (2020), č. článku 1900448. ISSN 1438-1656. E-ISSN 1527-2648
R&D Projects: GA ČR(CZ) GA16-09518S; GA ČR(CZ) GA19-18725S
Institutional support: RVO:68081723
Keywords : high-pressure torsion * microstructure evolution * nanostructured materials * behavior * mechanisms * resistance * stability * strength * model * creep * high-pressure sliding * high-pressure torsion * P92 (ASME Grade 92) steel * ultrafine grains
OECD category: Materials engineering
Impact factor: 3.862, year: 2020
Method of publishing: Limited access
https://onlinelibrary.wiley.com/doi/pdf/10.1002/adem.201900448

Creep testing is conducted on an advanced martensitic-ferritic creep-resistant P92 steel (ASME Grade 92) to evaluate the effects of grain refinement and the predeformation impact after processing by severe plastic deformation (SPD), namely, by high-pressure torsion and high-pressure sliding. Constant-load tensile creep tests are carried out in an argon atmosphere at 600 degrees C and under an applied stress ranging from 50 to 200 MPa. The results show that under the same creep loading conditions, the ultrafine-grained (UFG) microstructure states after SPD processing exhibit higher minimum creep rate epsilon(m) and creep fracture plasticity epsilon f, but significantly shorter creep lives in comparison with the coarse-grained (as-received) state of the steel. These distinct differences between the coarse-grained and UFG states are explained by the different deformation mechanisms that operate, creep behavior in a coarse-grained state is controlled by the intragranular climb of dislocations, while creep in UFG states can be interpreted as the synergistic action of the dynamic recovery of free dislocations at high-angle grain boundaries and grain boundary-mediated deformation processes.
Permanent Link: http://hdl.handle.net/11104/0302516