Is UNS J91153 Compliant with NACE MR0175/ISO 15156-3?

Introduction

This page addresses an inquiry regarding the compliance of UNS J91153 with NACE MR0175/ISO 15156-3. The inquiry relates to Table A.18 in Part 3, A.6.2 of the standard, which lists cast and wrought equivalents for various alloys.

The Question

The question asks whether UNS J91153 is compliant with NACE, given that Table A.18 lists cast or wrought S42000 but does not mention its cast equivalent CA40.

The Answer

Early versions of MR0175 did not include UNS S42000 in either the cast or wrought form. Wrought S42000 was added in 1994, but a cast version of S42000 was never balloted. The casting alloy J91153 is chemically different from S42000, which means it is incorrect to claim that it meets ISO 15156-3. A ballot would be required to change this, and Annex B of the standard provides guidance on CRA testing and balloting. The ballot form is available on the ISO website.

Conclusion

This question pertains to NACE MR0175/ISO 15156-3 A.6.2 Table A.18, and the reference cited is ISO 15156 Maintenance Panel Inquiry #2011-09.