The morphology and crystallographic feature of austenite formed from martensite during aging have been investigated in a Fe-10Cr-10Ni-2W maraging steel. The microstructure of solution-treated sample is fully martensite before aging. Four types morphology, such as lath-like, allotriomorph, Widmansta¨tten and wedge-shaped austenite. appeared in this maraging steel during aging. The reverted austenite is formed having both a Kurdjumov-Sachs(K-S) orientation relationship and a Nishiyama(N) orientation relationship with martensitic matrix. Furthermore, a wedge-shaped austenite is found to have a twin relationship between adjacent austenites. The twinned austenite is observed to have a very sharpy twin boundary, and longitudinal direction of the twin boundary is dependent upon both the beam direction and the orientation relationships between austenite and martensite. |
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