Effect of scattering vector of neutron diffraction for rolled steel sheets on neutron diffraction line-profile analysis

We investigated the effect of the relationship between the scattering vector of neutron diffraction and the sample direction processed by cold-rolling on line-profile analysis. It was revealed that dislocation parameters became unstable when using a diffraction profile at the scattering vector parallel to the rolling direction. This is probably due to the inhomogeneous elastic strain caused by the distribution of the Poisson's effect depending on the crystallographic orientation. On the other hand, the most ideal direction of the scattering vector for the line profile analysis is the normal direction of the rolled sheets. This is because the inhomogeneous elastic strain and the residual strain was small in this direction. The contribution of austenite and ferrite phases in the duplex stainless steels to the work hardening was also investigated by estimating dislocation density. The dislocation density in the austenite phase was much higher than that in the ferrite phase. Consequently, the austenite phase is mainly responsible for the work hardening with the cold-rolling. (author)