The theory for the diffusion-controlled growth of ferrite in steels that also contain substitutional solutes is fraught with difficulties when it comes to transformation at large supersaturations, where the bulk compositions of the ferrite and austenite do not differ much, but where local-equilibrium is nevertheless maintained at the transformation front. This requires the existence of a narrow variation in substitutional solute content in the austenite at the interface (so-called ‘concentration spike’) - so narrow that it has no physical meaning. Drawing on the theory for spinodal reactions, it is demonstrated here that there is a substantial penalty associated with the creation of such sharp changes in composition. Therefore, the spikes would never occur in practice. The actual distribution of solute would be over distances orders of magnitude larger than currently calculated, leading to slower growth rates than are predicted currently. The consequences of this conclusion place doubt both on the transition from local to paraequilibrium, and whether the latter state exists at all for reconstructive transformations.

当在大的过饱和状态下进行转变时，铁素体在也包含替代溶质的钢中的扩散控制生长的理论充满了困难，在该过饱和下，铁素体和奥氏体的整体组成相差不大，但是局部平衡是尽管如此，它始终处于转型的前沿。这要求在界面处的奥氏体中替代溶质含量存在狭窄的变化（所谓的“浓度峰值”）-如此之窄以至于没有任何物理意义。根据旋节线反应的理论，在此证明了与组成的这种急剧变化的产生有关的实质性损失。因此，尖峰在实践中永远不会发生。溶质的实际分布将比当前计算的距离大几个数量级，从而导致增长率低于当前的预测。这一结论的后果使人们既怀疑从局部均衡到超平衡的过渡，也怀疑后者对于重构性转换是否存在。