Martensitic stainless steels continue to be one of the most widely used corrosion resistant alloys in oil and gas developments. Determining if a martensitic stainless steel is acceptable in an unproven environment requires testing to confirm, but predicting the outcome of a given test environment is often initially based on personal experience rather than a qualitative and quantitative assessment. An empirical method for improving the predictability of NACE TM0177 Method A Tensile tests on modified 13Cr 110 ksi grade martensitic stainless steels based on an H2S/Chloride/pH function has previously been developed based on published data in order to address this uncertainty. The environments considered by this function are only limited by the capabilities of the NACE TM0177 Method A test, and provide a method for rapidly estimating if a M13Cr 110ksi grade should pass or fail in multiple different environments. As a follow-on to the development of this empirical method, data points from new tests
were used to check the general predictability of the H2S/Chloride/pH function. The general function was modified due to the addition of the new data, and subsequently checked again against a separate set of data. The nature and implications of these findings are discussed and conclusions drawn regarding the performance and value of the methodology for the evaluation of future materials applications.