Papers by Author: J. Lépinoux

Abstract: The conditions for nucleation of abnormal grain growth have been investigated using a 2D vertex simulation allowing for the presence of pinning centers. The topological characteristics of an “almost pinned” structure, compared to the classical grain growth with no pinning force, show a striking correlation between the grain size and the size of the neighbors of this potential abnormal grain. The main finding of this contribution is to stress the crucial importance of pinning particles, and to point to the stochastic nature of the nucleation event in abnormal grain growth.

Abstract: The observation of inhomogeneous, ‘sluggish’ recrystallization in ferritic steels has been extensively documented and discussed, particularly with reference to low carbon steels. Stabilized ferritic stainless steels are also prone to this phenomenon and, in many cases, exhibit the effect more strongly than their carbon counterparts. The situation for stainless steels is exacerbated in part by the topology of the cold rolled microstructure, which is composed of highly elongated and layered grains. In this work an attempt has been made to probe the key features of this process by means of a two-dimensional vertex simulation. Key microstructural characteristics such as subgrain and grain size, topology, misorientation and energy are varied in these simulations in an attempt to elucidate the mechanisms responsible for the final recrystallization. These simulations are compared and contrasted with experimental observations from the recrystallization of an AISI409 stainless steel.