MICROSTRUCTURE AND THE MECHANICAL PROPERTIES OF DUAL-PHASE STEEL PRODUCED BY INTERCRITICAL ANNEALING OF LATH MARTENSITE.

Abstract

Microstructure and tensile properties of a dual-phase (martensite plus ferrite) Fe-2. 3%Mn-0. 05%C-0. 03%Nb steel have been studied. In order to assess the effects of prior austenite grain size on microstructure and tensile properties, specimens with different prior austenite grain sizes were prepared by thermal cycling and thermomechanical processing. The fine dual-phase structure was superior in both strength and ductility to the coarse structure over a range of martensite volume fractions.