Effect of Bainite Crystallographic Texture on Failure of Pipe Steel Sheets Made by Controlled Thermomechanical Treatment

Resumo

The method of orientation microscopy (EBSD) is used to study the texture of low-carbon, low-alloy pipe steel sheets with a bainitic structure made by controlled thermomechanical processing. The specimens analyzed are inclined or not inclined towards forming separations (secondary cracks) in a fracture during mechanical testing. Formation of separations during failure of steel with a bainitic structure is connected with the presence in the material of regions with uniform orientation (001)<110> extended in the cold rolling direction. Formation of the regions is a consequence of features of γ→α shear transformation that commences at special boundaries between deformed austenite grains.