Distribution of Texture along Tube Wall Thickness of TA18 Alloy Tube

The texture of the inner layer, middle layer and outer layer of cold rolled TA18 alloy tube were investigated and analyzed by X-ray diffraction technique. Contractile strain ratio (CSR), determined by the texture, which can reflect mechanical property anisotropy of a tube was also tested. The results show that texture intensity has a big gradient along the tube wall; through the peak value of orientation density from the orientation distribution function (ODF), the variation gradient is over 17%, and texture types are different greatly among the layers. The texture of the middle layer measured by the method of thinning and flattening, although it is high for this tube, its CSR is only 0.95, less than that of use standard 1.3. It is due to that the texture is not uniform along the tube wall, there exists favorable texture in radial direction and negative texture in tangential direction, and strong negative texture leads to deterioration of the mechanical property. Confirming the distribution of texture along the tube wall can provide reference for forecasting and improving mechanical properties of the tube, and supply foundation to optimize production process.