FORMATION OF LAMELLAR FERRITEMARTENSITE DUAL-PHASE STRUCTURE
层片型双相组织的形成过程

The formation of the lamellar ferrite-martensite dual-phase structure developed by prequenching and subcritical quenching in 09SiCrMnMoRE steel has been studied. It is shown that during subcritical annealing, austenite pools are pref- erentially nucleated at prior austenite boundaries and martensite packet boundaries, and then austenite lamellae form at lath boundaries accompanied by cementite pre- cipitation and dissolution. The lamellar austenite growth along the lath and the martensite packet boundaries is beneficial to the decrease of both the interface and the strain energies which are necessary for austenite formation. As a result, the lamellar ferrite-martensite dual-phase structure is developed after quenching.