Effects of High Yield Ratio on Material Properties of Pipeline Steel

Abstract

The nominal yield ratio, true yield ratio and static toughness of five materials X80, X65, X60, X46 and Q235 have been tested in this paper. The yield ratio of pipeline steel is rising with the increase of strength level, which is inevitable for the high strength pipeline steel. Based on the analysis of static toughness calculated by the true stress-strain curve, it is indicated that the deformation energy of X80 pipeline steel after the necking process in the course of static tension is high comparatively, and the deformation energy of X80 pipeline steel before the necking process is closed to that of the pipeline steel X46 and X60 with low yield ratio. It is showed that the increase of yield ratio did not lead to the decline of the static toughness.