Ambiguity in NACE MR0175/ISO 15156-2:2009 (E) Regarding SCC Regions of Environmental Severity

This webpage addresses a question about the contradictory statements in Paragraph 7.2.1.2 and Paragraph 8 of NACE MR0175/ISO 15156-2:2009 (E) regarding the evaluation of carbon and low alloy steels for their resistance to HIC/SWC and SCC regions of environmental severity. The question seeks clarification about the maximum sulfur restriction of 0.003% and the different qualification requirements for various materials and potential cracking modes.

Explanation of Contradictory Statements

Contrary to the appearance of contradictory statements, the standard provides different qualification requirements for various materials and potential cracking modes. Clause 7 pertains to resistance to SSC, SOHIC, and SZC. 7.2.1.2 and 7.2.1.3 are only applicable to SSC, while Clause 8 is for the evaluation of carbon and low alloy steels for their resistance to HIC/SWC. For carbon steel products made from rolled plates, HIC/SWC and SOHIC/SCZ should be considered.

Related to NACE MR0175/ISO 15156-2 Clause 7.2.1.2

This question is related to NACE MR0175/ISO 15156-2 Clause 7.2.1.2. For further assistance in understanding and defining the requirements of NACE MR0175, contact OGC Energy.

Reference: ISO 15156 Maintenance Panel Inquiry #2012-09.