EBSD Study on Transverse Tensile X80 Grade Pipeline Steel

Transverse tension testing was carried out on an X80 grade linepipe to investigate the deformation behavior and the evolution of microstructure by means of SEM-EBSD (Electron Backscattered Diffraction) technique. Test results show that uniform elongation could achieve up to 7% in transverse tension for an X80 linepipe. Microstructural analysis shows that primary equiaxed ferrite grains obviously changed after the tension test to elongate along the length of pipeline body, but the substructure did not increase much revealing that the ferrite in X80 steel could contribute to a certain extent for ductile deformation. Orientation imaging of EBSD analysis displays that the texture components, such as γ-texture, and a little Goss and Copper texture, occurred after deformation. Otherwise, a small amount of primary α-texture still remains. It can be recognized that X80 has good deformational stability.