Reverse transformation behavior during intercritical annealing was studied in Fe-0.3 mass%N binary alloy. Two morphologies of acicular and globular austenite are formed during reversion. The globular austenite has almost same orientation with one side of adjacent prior austenite grain and grows into the martensite with larger deviation angle from Kurdjumov-Sachs orientation relationship (K-S OR). On the other hand, the acicular austenite holds a near K-S OR with its surrounding martensite matrix. A large amount of retained austenite was obtained by a simple intercritical annealing due to enrichment of nitrogen into reverted austenite.
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