J025 Effects of Mn and Cr combined addition on bainitic transformation in Fe-0.3N alloy

摘要

Nitrogen (N) is an interstitial element that thermodynamically stabilizes austenite (γ) phase like carbon (C). In the Fe-N system, a large amount of retained γ can be obtained during ferrite transformation because of the higher eutectoid composition by comparison to Fe-C binary system and the ability to enrich more nitrogen into the γ [1]. We have previously studied the effect of Mo, Cr and Si addition on bainite transformation in Fe-N alloy and found that Y'-Fe4N precipitation was suppressed and the volume fraction of retained γ was obtained 10.5% by Cr addition [2]. However, the effect of Mn, which can stabilize the austenite phase, is not clarified yet. Therefore, the purpose of this study is to clarify the effects of Mn addition and multiple addition both of Mn and Cr on the bainite transformation of Fe-N alloy.