Investigation to the Effect of Banding on Impact Resistance Behavior Microalloyed Pipeline Steel

Layering of microstructure parallel to the direction of flow of steel during hot working process is called banding. In the present paper، the severity of pearlitic–ferritic banding in API GRB microalloyed steel and its effects on impact energy is studied. Specifically، Impact properties are compared between banded and non-banded samples along two directions perpendicular and parallel to the rolling direction. Metallographic examinations together with impact charpy tests at zero and 20 °C were done both parallel and perpendicular to the rolling direction. The results showed the dependence of impact energy to the sample direction relative to the rolling i. e decreasing energy in rolling direction and increasing it in per pendicular direction to the rolling