PR185-173611-R01 Applicability of Existing Metal-Loss Criteria to Low-Hardening Steels

This two-year project has evaluated the applicability of B31G and Modified B31G corrosion assessment criteria for applications to low-hardening pipe steels, whereas these criteria were originally developed and calibrated for high-hardening steels common in lower strength grades and in older steel production. This project builds upon work completed in EC-2-6 and EC-2-7 by trending changes in pipe properties over time, and by quantifying the role of the flow response, including the influence of strain hardening on failure response and predicted failure pressure for metal loss defects in pipelines. This report presents the outcomes of this two-year project in regard to the need for corrections for these criteria, and where required considers suggested corrections to ensure the usual margin of safety afforded by these criteria.