Effects of Grain Refinement and Predeformation Impact by Severe Plastic Deformation on Creep in P92 Martensitic Steel. Issue 1 (14th August 2019)

• Record Type: Journal Article
• Authors: Sklenicka, Vaclav; Kral, Petr; Dvorak, Jiri; Takizawa, Yoichi; Masuda, Takahiro; Horita, Zenji; Kucharova, Kveta; Kvapilova, Marie; Svobodova, Marie
• Other Names: Kawasaki Megumi guestEditor.; Figueiredo Roberto B. guestEditor.; Zhilyaev Alexander P. guestEditor.
• Is Part Of: Advanced engineering materials. Volume 22:Issue 1(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-08-14
• Subjects: creep -- high-pressure sliding -- high-pressure torsion -- P92 (ASME Grade 92) steel -- ultrafine grains; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201900448
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : 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 °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 ϵ ˙ m and creep fracture plasticity ϵ 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. Abstract : Creep testing is conducted on an advanced creep‐resistant P92 steel to evaluate the effects of grain refinement and the predeformation impact after processing by high‐pressure torsion and high‐pressure sliding. The ultrafine‐grained microstructures after severe plastic deformation exhibit faster minimum creep rate and increased creep fracture plasticity but significantly shorter creep lives in comparison with the coarse‐grained steel.