| The mechanical properties of virgrin martensite, ausformed martensite, marformed martensite, tempered ausformed-martensite, tempered marformed-martensite and reversed austenite produced by phase transformation and thermomechanical treatment of Fe-30%Ni-0.2%C alloy have been investigated. As and A, point are increased with the amount of deformation and tempering temperature, the increase of A_s point in marformed martensite being especially great, The tempering resistance of marformed martensite is superior to that of ausformed martensite due to the increase in A_s point. The strength of reversed austenite transformed from ausformed martensite and marformed martensite is decreased at the high degree of deformation due to disappearance of considerable amount of strengthening effect introduced by thermomechanical treatment during the reverse transformation. The elongation in deformed austenite decreased with increasing deformation; those of ausformed martensite and marformed martensite, however, maintained constant values, independent of the strength. Consequently, marforming treatment is superior to ausforming for strengthening Fe-30%Ni-0.2%C alloy. |
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