Static tensile deformation behavior of a lean duplex stainless steel studied by in situ neutron diffraction and synchrotron radiation white X-rays

中性子と放射光白色X線を利用した二相ステンレス鋼の引張変形挙動その場測定

土田 紀之*; 川畑 拓司*; 石丸 栄一郎*; 高橋 明彦*; 鈴木 裕士  ; 菖蒲 敬久  

Tsuchida, Noriyuki*; Kawahata, Takuji*; Ishimaru, Eiichiro*; Takahashi, Akihiko*; Suzuki, Hiroshi; Shobu, Takahisa

二相ステンレス鋼の引張変形挙動を明らかにするため、中性子と放射光白色X線を利用したその場測定を行った。放射光白色X線の結果から、引張変形中でS32101の硬い相がフェライトからオーステナイトに変化した。これはより大きな力により後半の相へ変化したためであるといえる。中性子実験からは、S32101中のより高い応力下での相の応力分配が見つかった。ゆえに、S32101中の加工硬化率は相と相の応力分配により説明することができる。

To investigate the tensile deformation behavior of a lean duplex stainless steel (S32101) from the viewpoints of plastic deformability among phases or grains, we performed static tensile tests, in situ neutron diffraction, and white X-ray diffraction experiments at room temperature. From the experimental results of synchrotron radiation white X-ray diffraction experiments, the hard phase of S32101 was changed from the ferrite phase to austenite one during tensile deformation. This led to a larger stress partitioning between the phases at the latter stage of deformation. From the experimental results of in situ neutron diffraction, it was found that the stress partitioning of the phase in the S32101 was the largest among the present results. Therefore, the larger work hardening rate of S32101 can be explained by the large stress partitioning of the phase, that between and phases and volume fraction.