中性子回折によるフェライト単相鋼のひずみ時効硬化異方性の検討

Neutron diffraction study on anisotropy of strain age hardening in ferritic steel

鈴木 徹也*; 山中 啓輔*; 石野 まゆ子*; 篠原 康浩*; 長井 健介*; 津留 英司*; 徐 平光   

Suzuki, Tetsuya*; Yamanaka, Keisuke*; Ishino, Mayuko*; Shinohara, Yasuhiro*; Nagai, Kensuke*; Tsuru, Eiji*; Xu, P. G.

The work-hardening characteristics of anisotropic tensile deformations and the corresponding residual strain changes of pre-strained ferritic steels without and with ageing treatment were investigated by using angle dispersive neutron diffraction and electron back-scattering diffraction. The plastic deformation along the pre-strained direction leads to evident work-hardening at the beginning stage, showing discontinuous yielding behavior. Comparably, the plastic deformation perpendicular to the pre-strained direction shows continuously yielding. The tensile and compressive residual strains were found in the 200 and 110 grains along the pre-strained direction, respectively. It is also found that the difference in various oriented grains after strain ageing become more evident along the pre-strained direction but smaller perpendicular to the pre-strained direction, revealing a higher work hardening capability in the former case than in the latter case.