Hello Hossein Ahmadi ,

Regardless of the degree of recrystallization, traces of the rolling lines are observed. Naturally, the surface is saturation, and the core is smaller, and traces of rolling are traced as strips.

Dear Hossein

You might see flow lines on the surface of a cold rolled-aluminum alloy, i.e. 5xxx, after recrystallization. However, those flow lines might not appear in the microstructures of the sub-surface layer of the recrystallized aluminum after a standard metallographic preparation of the recrystallized aluminum for optically microscopy, i.e., examination of the microstructures of the sub-surface layer of the recrystallized aluminum by an optical microscope. This is because the flow lines might disappear as a result of the metallographic polishing, grinding, and the chemical etching procedures of the aluminum.

In the meantime, one would see the orientation of the grains of the recrystallized aluminum in a direction which corresponds to the cold rolling direction.

Flow lines often can be revealed by etching the surface or a section of a metal part.

In the processing of 5XXX series aluminum alloys, flow lines similar to the Lüders bands seen in steels, develop (Swain et al. J. Inst. Met., 81, 625 (1952) ). These markings develop because Mg, which is concentrated at grain boundaries, prevents the transfer of strain from grain to grain (Sanders, et al., in Aluminum Alloys -Contemporary Research and Applications , New York: Academic Press, A. K. Vasedovan and R. D. Doherty, eds., p. 96 ) You can prevent them from being created by increasing dislocations density (i.e., straining the material past its yield point, just like it happens with the Lüders bands ). T