High orientation resolution texture and residual stress measurement of multilayered steel using neutron diffraction

徐 平光; 井上 純哉*; Gong, W.*; Harjo, S.; 鈴木 裕士; 秋田 貢一

no journal, , 

Different with the monochromatic neutron diffraction texture measurement, the recent pulsed polychromatic neutron diffraction texture measurement can provide lots of additional valuable information: the crystal cell structure, the phase fraction, the coherent crystallite size, the root mean square microstrain, and/or the macroscopic/intergranular stress/strain, etc. Here, the multiphase textures and the phase stress tensors in as-received austenite/martensite multilayered steel sheets were evaluated using a polychromatic texture measurement. The Eulerian cradle was setup at TAKUMI to enable scanning all the sample orientations without evident change in the orientation resolution. The multilayered microstructure distribution, (200) crystallographic pole figure of martensite layers, together with the measured strain pole figures of martensite (110) and austenite (111) through the individual peak fitting were evaluated. The macro stress tensor analysis with a plane stress assumption shows a RD-TD in-plane compressive stress distribution in martensite layers, and a balanced RD-TD in-plane tensile stress distribution in austenite layers. Such phase stress partitioning distribution occurred mostly due to the volume-expansive martensite transformation during the sample water quenching.