2003 Volume 89 Issue 6 Pages 653-658
A rolling method to increase the width of materials would have advantages in multi-width strip production, giving high yield efficiency and productivity. In addition, textures of strips could be chnged by the traverse strain. It is, however, still difficult to produce transverse metal flow in thin strips. The authors suggested a new method for spread rolling of thin strips by multi-pass grooved rolling. In this study, the method has been applied to a Cr 11% ferritic stainless steel strip and its effect on the ridging behaviour has been investigated. The thin 1.0 mm thick and 70 mm wide steel strips are widened up to approximately 72 mm by 35%-reduction. The textures of the spread rolled steel contain relatively shaper γ-fiber band and weaker α-fiber than the flat rolled strips, so that the planer anisotropy of the spread-rolled strips are smaller than that of the flat-rolled strip. The texture is generally weakened by subsequent recrystallization annealing. Applying EBSP analysis on ND-plane of the spread rolled strips, it is found that the grain clusters of certain orientations aligning along the rolling direction, which causes severe ridging, are scattered in the strips by spread rolling and the allocation of <001>//ND grains is remarkably different from those of the stock and flat rolled strips. It is notable that the improvement of the ridging behaviour on the ferritic steel is brought by the spread rollling.