Texture and residual-stresses analysis in Zircaloy-4 cylindrical samples

Texture and residual-stress analysis using X-ray diffraction have been carried out on cylindrical Zircaloy-4 samples in cold-worked and finished state. The (00.2) pole figure of finished tubes shows an important asymmetry in the tangential direction (TD) not observed on unrolled tubes. This asymmetry vanishes at a 5-mu m depth. A noticeable variation of the texture index J has been pointed out within the first micrometers from the surface of the tubes. Strain measurements in tangential and longitudinal directions have been carried out on the (10.4) and (20.2) planes, In the tangential (hoop) direction, compressive stress on the outer surface decreases rapidly in the first layers and remains constant at the analysed depth. Axial stress analysis shows the opposite si,on for the two different diffracting planes an the cold-worked tubes, indicating the existence of second-order stresses. (C) 1998 Elsevier Science B.V. All rights reserved.