Overview The first four parts of this series have described the updated Becht HTHA model and presented extensive validation for its application to Carbon Steel and C-0.5Mo.  Based on this validation, time-based Nelson Curves for Carbon Steel (CS) and C-0.5Mo suitable for inclusion in API RP 941 [1] are now presented. General Assumptions Curves are […]

Overview Part 3 of this series presented the data set and calibration used to characterize C-0.5Mo performance.  This part extends the calibration to Carbon Steel using the same basic calibration procedure.  Unlike C-0.5Mo where carbon activity was used as the calibration parameter, for Carbon Steel the carbon activity is assumed to be 1 in all […]

Overview Part 2 of this series presented the extension of our model to C-0.5Mo material and calibration to very detailed through-wall damage data for five C-0.5Mo cases (from [1]).  This part completes the analysis of C-0.5Mo by including data from API RP 941 [2] (including both plotted and file points) and the remaining cases from […]

Overview In Part 1 of this blog series an overview of two basic extensions to our void growth based HTHA model was given.  In this part, validation of through-wall damage predictions are provided by leveraging the unique and exceptionally detailed work presented in the Peng Lui PhD dissertation [1].  Validation is critical for any model, […]

Overview This past spring, we described how we’ve incorporated well-established void growth modeling into our high temperature hydrogen attack (HTHA) assessment approach [1].  The purpose of this extension was to blend a reliable time basis for HTHA with our existing critical factor-based method (also published in the Inspectioneering Journal 6 years earlier [2]). The Inspectioneering […]