Primary Recrystallization of Invar, Fe-36%Ni Alloy: Origin and Development of the Cubic Texture

This short review summarizes the main results acquired by Penelle's group at the Universite Paris Sud 11 in Orsay during the last 10 years on recrystallization of the Fe-36%Ni so-called Invar alloy. The formation and the development of the cube texture after high deformation by cold rolling (CR) and subsequent annealing is interpreted from a multiscale analysis based on TEM, SEM/EBSD, X-ray, and neutron diffraction measurements coupled with a Monte Carlo simulation. It is shown that the cube orientation which presents a cellular deformation substructure consumes the noncube matrix. This is interpreted by the high difference of stored deformation energy between the cube and the recovered matrix which is the main driving force for recrystallization. The parameters disorientation and subgrain size are also discussed. For low CR reductions, the difference of stored energy is weaker and as a consequence other orientations of the matrix have time to develop which leads to a softening of the recrystallization texture, the texture randomization is intensified by annealing twinning.