Influences of microstructure and texture on crack propagation path of X70 acicular ferrite pipeline steel

Hao Yu School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China

摘 要：The aspects of two pipeline steels with different technologies were investigated by using transmission electron microscopy （TEM） and electron back-scattered diffraction （EBSD）. The microstructure presents a typical acicular ferrite characteristic with fine particles of martensite/austenite （M/A） constituent, which distributes in grains and at grain boundaries. The bulk textures of the pipe-line steel plate are {112}<110> and <111> fibers, respectively, and the {112}<110> component is the favorable texture benefiting for drop weight tear test. Moreover, low angle boundaries and low coincidence site lattice boundaries are inactive and more resistant to fracture than high energy random boundaries.

关键词：