Effect of Finishing Temperature on Hot Band Textures in an IF Steel

Abstract

The effect of hot rolling parameters on texture development was studied in a 0.004%C-0.02%Nb-0.02%Ti interstitial free (IF) steel. Two austenitizing temperatures (1250 or 1150°C) and two levels of reduction (90 or 75%) were employed. Six different finishing temperatures were investigated: 1020, 920, 870, 820, 720 and 620°C. The final ferrite textures were measured; these are presented in the form of φ₂=45° ODF sections and of intensities along the RD, TD and ND fibres. The experimental textures display two contrasting behaviours, which depend on finishing temperature. The textures corresponding to the three higher finishing temperatures are relatively flat, with the rotated cube {001} <110> prevailing. Sharper textures are produced at the three lower temperatures; orientations between {001}–{111} <110> are enhanced, the ND || <111> fibre is strengthened, and orientations around {554} <225> are clearly more intense. The experimental results are compared with predictions based on the Kurdjumov-Sachs relation; the differences observed indicate the occurrence of both variant selection and selective growth during transformation.