eutectoid reaction

When cooling, peritectic reaction between α-Mg and Zr happened in the Zn-rich area in the grains, while eutectic reaction and eutectoid reaction happened in grain boundaries.

冷却时，α-Mg与Zr在晶内富Zn处发生包晶反应，晶界处发生共晶反应和共析反应。

The experiment results show that the connection zone may be divided into multicomponent eutectoid, tungsten carbide and narrow ferrite and the interface is found to be a metallurgical bond because of the element diffusion, metallurgy reaction and formation of the new compound phase during the cast-in process.

实验结果表明：结合层是由窄小的铁素体带和多元共析体+条块状WC组成，界面元素发生扩散及冶金反应并有新相产生，呈典型的冶金结合。

Both the austenite-graphite eutectic reaction temperature and eutectoid reaction temperature are higher than those of austenite-cementite.

奥氏体-石墨共晶和共析反应温度也都高于奥氏体-渗碳体的共晶和共析反应温度。

Calculation of the driving force for nucleaction ( growth) gives an evidencs that the leading phase of the eutectoid reaction in hypoeutectoid steels is ferrite while that in hypereutectoid steels is cementite.

由形核（长大）驱动力的计算证明，亚共析钢共析反应的领先相为铁素体，而过共析钢的领先相为渗碳体。