Estimate of Y/T ratio and uniform elongation capacity of pipeline steels from yield strength

This paper compares the prediction capabilities of the API1104-Appendix A equation for estimating the axial uniform elongation capacity, uEL, from yield strength. The experimental data was obtained from 25 mm wide full thickness longitudinal tensile tests on Grade X60 through X100 pipeline steels. The experimental data was also used to develop alternative experimentally validated Y/T ratio dependent lower bound estimates of uEL from yield strength. The comparisons demonstrate that the simple API equation could be inappropriate for describing the post-yield response of contemporary pipeline steels. To prevent that non-conservative predictions are made, the alternative experimentally validated UGent estimates of Y/T ratio and uEL from yield strength are recommended.