Susceptible material with SSC/SCC/HIC

[dursosono]

Does material SS more susceptible of SSC/SCC/HIC than CS? According to NACE MR0175 part-2, P-No. 1 has acceptable with this Standard. In part-3 for SS (P-No. 8) has limitation max parsial pressure of H2S. It's mean for P-No. 1 is acceptable without limitation of max H2S partial press.?

 

[SJones]

Susceptibility is not only about looking in ISO 15156. It can be down to chemical compositions or heat treatments incorrectly applied and a myriad other things whilst still actually complying with the standard! In another thread, you were referred to the following link:

http://www.capp.ca/library/publications/industryOperations/pages/pubInfo.aspx?DocId=109839

Reviewing this document will help you work through the application of ISO 15156. From it, you should deduce that HIC is not an expected failure mode of an austenitic stainless steel as an example.

However, to answer the last part of your question: there is no maximum H2S partial pressure limit associated with the application of carbon steel.

Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[strider6]

carbon, low alloy steel are not susceptible to SCC (chloride stress corrosion) while SS are not susceptible to HIC.
as SJones said there are also other mechanims of corrosion that you've to consider while selecting a materials.

S

Corrosion Prevention & Corrosion Control

 

[EdStainless]

If there was one class of alloys that resisted all of these mechanism and had a reasonable cost you can bet that everyone would be using it.
All design is a compromise between cost, life, risk of failure, likelihood of various corrosion mechanism and manufacturing limitations.

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