1988 年 28 巻 10 号 p. 826-835
Experimental data in the literature on the partition of alloying element during the growth of Proeutectoid ferrite allotriomorphs in 9 Fe-C-X systems (X=Al, Si, V, Cr, Mn, Co, Ni, Cu and Mo) are compared with the theory of difusional growth which assumes that all component species are in local equilibrium (LE) at the advancing interface and also with the theory which assumes that only local equilibrium with respect to carbon is maintained at the interface (paraequilibrium (PE)). The temperature ranges in which the formation of ferrite occurs with or without alloy partition are explained in a qualitative manner by the former theory. The partition behavior in each alloy is discussed in terms of thermodynamic properties of alloy element. A major deviation of partition from the LE theory occurs at lower reaction temperatures in alloys with higher Mn or Ni content. A practical means of estimating the temperature of the cassation of partition in such alloys is considered. The growth kinetics of alloy element partitioned and no partitioned ferrite allotriomorphs are briefly reviewed. In alloys with X which has a strong affinity with carbon in austenite, such as Cr, Mn, Mo, etc., the growth kinetics differ remarkably from both the LE and the PE theories, the reasons for which are yet to be explained adequately.
