NACE MR0175 / ISO 15156 Standards for Impellers Manufactured with Martensitic Stainless Steel UNS S41500

This article provides information on the NACE MR0175 / ISO 15156 standards for impellers made with martensitic stainless steel UNS S41500. These standards require that impellers exhibit a threshold stress that is greater than or equal to 95% of the actual yield strength (AYS) in the anticipated service environment. Testing may be required according to NACE TM0177 2016.

Clarifying the Requirements of Notes “”c”” of Table 22

Notes “”c”” of Table 22 state that in laboratory SSC tests, the alloy shall exhibit a threshold stress of 95% of the AYS. If the design stresses for the product are less than the actual yield strength by a factor of 1.5, what stress level is allowed to be used in laboratory tests for SSC?

The answer is that Table A.22 does not provide for lower acceptable stress levels than the 95% threshold stress of the AYS. Additionally, product/component design stresses are generally not covered by NACE MR0175/ISO 15156.

Assistance from OGC Energy

The team at OGC Energy offers services to assist clients in defining the qualification requirements for martensitic stainless steels used for compressor components.