Reverse austenite transformation behavior in a tempered martensite low-alloy steel studied using neutron diffraction

Tomota, Yo*; Gong, W.*; Harjo, S.   ; Shinozaki, Tomoya*

The microstructure evolution during reverse transformation of a Cr-Ni-Mo steel consisting of tempered lath martensite and Cr carbide was examined using neutron diffraction at high temperatures. The microstructural change from a reversed coarse-grained structure to a fine-grained polygonal structure by further annealing was monitored through a decrease in the diffraction intensity caused by primary extinction and the full width at half maximum. This result is different from that for a bainite steel, showing good coincidence with the observations using electron back scatter diffraction.