Title

CREEP PROPERTY OF AUSTENITIC STAINLESS STEEL WITH LATH STRUCTURE FORMED BY DISPLACIVE REVERSION

CREEP PROPERTY OF AUSTENITIC STAINLESS STEEL WITH LATH STRUCTURE FORMED BY DISPLACIVE REVERSION

Authorship

Nakada, Nobuo; Fukae, Daisuke; Kitaura, Tomoyuki; Tsuchiyama, Toshihiro; Takaki, Setsuo

Nakada, Nobuo

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Fukae, Daisuke

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Kitaura, Tomoyuki

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Tsuchiyama, Toshihiro

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Takaki, Setsuo

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DOI

10.5151/2594-5327-16862

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Abstract

The effectiveness of microstructure control using displacive reversion on creep property was verified in a metastable austenitic stainless steel with a chemical composition of Fe-14%Cr-11%Ni. The steel plates were cold-rolled until the austenite phase fully transforms to deformation-induce α’ martensite, and then rapidly heated to 923K to reverse the martensite to austenite. By the thermomechanical treatment, fine lath austenitic structure containing high-density dislocation was formed with a mechanism of displacive reversion from deformation-induced α’ martensite to austenite. The thermomechanical-treated specimen with lath structure had approximately two times longer creep fracture lifetime compared to the specimen with equiax-grained structure. This results means that the microstructure control to lath structure effectively enhances creep property of austenitic heat-resistant steel.

The effectiveness of microstructure control using displacive reversion on creep property was verified in a metastable austenitic stainless steel with a chemical composition of Fe-14%Cr-11%Ni. The steel plates were cold-rolled until the austenite phase fully transforms to deformation-induce α’ martensite, and then rapidly heated to 923K to reverse the martensite to austenite. By the thermomechanical treatment, fine lath austenitic structure containing high-density dislocation was formed with a mechanism of displacive reversion from deformation-induced α’ martensite to austenite. The thermomechanical-treated specimen with lath structure had approximately two times longer creep fracture lifetime compared to the specimen with equiax-grained structure. This results means that the microstructure control to lath structure effectively enhances creep property of austenitic heat-resistant steel.

Keywords

Martensitic reversion; Austenite; Lath structure; Creep.

Martensitic reversion; Austenite; Lath structure; Creep.