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.
Key words: Modified 13Cr, SSC, Martensitic stainless steel, Sour service, NACE TM0177 Method A
Test