+44 (0) 114 4000850   |   US toll-free 877-399-1010
office@oilandgascorrosion.com

FAQs

Difference between the NACE MR0175 requirements of SSC and HIC/SWC

Viewed 6040 Times

Question: There is ambiguity between two passages, they contradict, paragraph 7.2.1.2 “SSC regions of environmental severity” of NACE MR0175/ISO 15156-2:2009 (E) to 17 Paragraph 8, “Evaluation of carbon and low alloy steels for their resistance to HIC/SWC” of NACE MR0175/ISO 15156 – 2:2009 (E) The paragraph 7.2.1.2 for Region 0 – For pH2S <0.3 kPa (0.05 psi) “ Normally, no precautions are required for the selection of steels for use under these conditions, whereas paragraph 8, says even trace amounts of H2S and shall consider HIC/SWC testing of these products” In addition the Sulfur restriction in the chemistry of.003% maximum.

Answer:

“Your quoted passages of the standard are not contradictory. The standard provides different qualification requirements for different materials and different potential cracking modes. Clause 7 is for “- – steels with resistance to SSC, SOHIC, and SZC”. 7.2.1.2 & 7.2.1.3 are only applicable to SSC. Clause 8 is for “Evaluation of carbon and low alloy steels for their resistance to HIC/SWC”. For carbon steel products made from rolled plate, in addition to consideration of SSC resistance, HIC/SWC shall be considered (clause 8) and SOHIC and SCZ should be considered (clause 7.2.2).”

This question is in relation to NACE MR0175/ISO 15156-2 Clause 7.2.1.2

Reference: ISO 15156 Maintenance Panel Inquiry #2012-09

At Oil & Gas Corrosion we can help you understand and define the requirements of NACE MR0175.

 

With a wealth of experience in the oil and gas industry, we provide independent materials and corrosion consultancy to help companies reduce risk, save money and apply best practice in their oil and gas businesses.

Find out more by getting in touch – you’ll get an answer from a qualified, experienced materials engineer every time.

 

USA toll-free

 

US: 877-399-1010 (toll free)
UK: +44(0)1144000850

66 Eldon St
Sheffield
S1 4GT
United Kingdom

 

Was this answer helpful ? Yes / No