強圧下冷延されたFe-0.3mass%Si合金およびFe-0.3mass%Al合金の再結晶挙動と集合組織の発達

Abstract

The effect of Si and Al additions on the recrystallization behavior of severely cold-rolled Fe by 99.8% reduction was investigated in comparison with a previous study on pure Fe6). In Fe-0.3mass%Si alloy, recrystallized grain with {411} <011> and {411} <148> preferentially nucleated at an early stage of recrystallization, and the texture did not changed substantially with the progress of recrystallization, which supports the oriented nucleation theory. The {411} <148> texture significantly increased at the expense of recrystallized grains with {100} <023> and {322} <236> during normal grain growth. In Fe-0.3mass%Al alloy, dynamic recovery during heavy cold-rolling and substantial subgrain growth during low temperature annealing (350˚C) occurred, similar to the case of pure Fe and different from that of Fe-0.3mass%Si alloy. This is presumably because of the subtle influence of Al addition on cross-slip frequency and smaller solute-vacancy interaction as compared with Si addition. Furthermore, at the early stage of recrystallization, nuclei had similar orientations as cold-rolling texture. With the progress of recrystallization, {100} <012> and {111} <112> orientations intensified. In the following normal grain growth, {100} <012> texture intensified. However, the change in the texture during growth cannot be explained only by the size effect. A rigorous grain growth simulation model is required to explain the experimental facts by considering the dependency of grain boundary mobility and energy on grain boundary characteristics.