Abstract
Planar anisotropy of r value in high strength cold rolled steel sheets produced at mill, of which composition are low C-Si-Mn-Nb-or low C-Si-Mn-Nb-Ti, is r45>r90>r0 type. The reason for the development of this type planar anisotropy in these high strength cold rolled steel sheets has been investigated from the view point of texture and microstructure.
The following results are obtained:
(1) These high strength cold rolled steel sheets have r45>r90>r0 type planar anisortopy even after recrystallization annealing, which is attributed to the remaining {211} <011> and {100} <011> components.
(2) These retained components are not attributed to the partial recrystallization, but mainly to the both effects of strong cold rolled texture due to strong hot rolled texture and recrystallization in situ due to fine precipitates of Nb (C, N) or Ti (C, N).
(3) It is suggested that the hot rolled texture has a strong influence on the recrystallization texture in cold rolled steel sheets containing Nb or Ti.
