Dislocation characteristics of martensitic steel studied by neutron diffraction experiment

Kawasaki, Takuro   ; Harjo, S.   ; Gong, W.; Aizawa, Kazuya  ; Iwahashi, Takaaki; Shi, Z.*; Li, J.*; Tomota, Yo*; Ungr, T.*

To evaluate the characteristics of the microstructure of materials, such as dislocation density, dislocation character and crystalline size, is as important as elastic strain in order to understand the mechanical properties of the materials. These characteristics can be obtained by analyzing the peak profile in X-ray or neutron diffraction patterns. Although high-penetrability of neutron enables direct observation of the characteristics inside bulky materials, not much research on the microstructure which uses neutron diffraction is available. In the present study, the dislocation characteristics of a martensitic steel during tensile deformation was investigated by in-situ neutron diffraction experiment using Engineering Material Diffractometer TAKUMI at BL19 of MLF, J-PARC and CMWP method. According as the strain increases, significant increasing of the correlation between the dislocations was observed though the increasing of dislocation density is not very much.