Comparison between a predicted and an experimentally measured residual stress field generated by side-punching of API X65 steel

Abstract

A residual stress field was generated by a circular, flat-ended, rigid punch indenting a thick test specimen extracted from X65 grade-controlled-rolled pipeline steel. Laboratory X-ray diffraction was used to measure residual stress field the near-surface, whereas the contour method and neutron diffraction were used to quantify the through-thickness residual stress field. A numerical method was proposed to account for gauge volume variation which allowed a direct comparison of the Finite Element prediction with the experimental measurements. A good agreement between the measurements and prediction was observed, showing that the through-thickness compressive residual stress reaches the highest magnitude in the centre of the specimen. The validated results can be used with confidence for residual stress-crack interaction studies in single-edge notched bend SEN(B) and single-edge notched tension SEN(T) fracture specimens which are common in the oil and gas industry due to the inherited close level of constraint experienced in a pipe.