Real time observation of martensite transformation for a 0.4C low alloyed steel by neutron diffraction

中性子回折による0.4C低合金鋼のマルテンサイト変態のリアルタイム観察

Wang, Y.*; 友田 陽*; 大村 孝仁*; 諸岡 聡  ; Gong, W.*; Harjo, S.   

Wang, Y.*; Tomota, Yo*; Omura, Takahito*; Morooka, Satoshi; Gong, W.*; Harjo, S.

A high-intensity and high-resolution neutron diffractometer with a thermomechanically controlled processing simulator was employed in-situ to investigate martensite transformation behavior with and without ausforming for a medium-carbon low-alloy steel. Serial neutron diffraction profiles have revealed that the transformation behavior could be successfully monitored during quenching with and without the ausforming process. The lattice parameter and the full width at half maximum of austenite peaks significantly decreases and increases upon martensite transformation, respectively. After ausforming, the data reveal that lattice parameters are larger in austenite whereas smaller in martensite compared with those in the non-ausformed case, which is ascribed to the introduced dislocations. The cutting-edge operant quantitative measurements with neutron diffraction for steel production is demonstrated.