Development of Recrystallization Texture in Severely Cold-rolled Pure Iron

Abstract

The mechanism of recrystallization texture development is changed by the chemical composition of materials, cold-rolling reduction, and annealing conditions. This study discusses the development of recrystallization texture for severely cold-rolled pure iron. In cold-rolled iron with 99.8% reduction, the deformation texture was a strong α-fiber (RD// < 011 > ) with high strain. During annealing in a temperature range from 20°C to 800°C, in this highly strained α-fiber, the microstructure started to recover from a low temperature. Thereafter, recrystallized grains began to appear at 350°C, and many recrystallized grains were generated at random locations. Their textural components were {100}, {211}, {111}, and {411}, which were already included in the α-fiber. At 550°C, recrystallization was completed, and the resulting recrystallization texture was similar to the original cold-rolling texture. This texture was developed by unique microstructural changes, which could be classified as continuous recrystallization. During grain growth stage, the recrystallization texture changed into the {100} < 012 > component presumably by the selective growth of recrystallized grains governed by the size effect.

Recrystallization Behavior and Texture Evolution in Severely Cold-rolled Fe-0.3mass%Si and Fe-0.3mass%Al Alloys

“…1) In contrast, Gobernado et al explained the formation of recrystallization texture based on the oriented nucleation theory of recrystallization in a Fe-3.2mass%Si alloy that was cold-rolled at 95% reduction in which recrystallized grains with {311} < 136 > orientation preferentially nucleated in the deformed grains with {100} < 011 > orientation and recrystallization completed by their growth, 2) despite the fact that the deformed {100} < 011 > grains 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 Fe. 6) 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 ND// < 111 > during normal grain growth.…”

“…1(b). Previous study of pure iron by the present authors, 6) revealed that α-fiber texture with the maximum intensity in {411} < 011 > developed after sever cold-rolling. Accordingly, a difference in severe cold-rolling texture between Fe-0.3mass%Si alloy and pure iron was recognized.…”

“…This is in contrast with the previously reported result of pure iron, in which recrystallized grains had similar orientations as the cold-rolling texture. 6) As recrystallization progressed, recrystallized grains with orientations from {100} < 012 > to {311} < 136 > and from {111} < 011 > to {111} < 112 > were observed as shown in Fig. 6(b).…”

“…For a purpose of comparison, a change in the hardness of pure iron severely cold-rolled at 99.8% reduction 6) was also plotted in Fig. 3.…”

“…However, there have been few reports on the origin of the recrystallization texture, 6) and it still remains to be clarified.…”