Moderate Sour Service (N) NACE MR0175/ISO 15156

[darrenyee88]

Hi All,

In NACE MR0175 moderate sour service , the chemical properties requirements for Sa 516 Gr 70 is of below ,
Carbon: 0.20% max
Sulfur: 0.002% max
Phosphorous: 0.020% max
Manganese: 1.2% max
Carbon Equivalent: 0.38% max
Nickel content in filler material and weld deposit shall be less than 1.0%.

What I want to ask is that, if the CEQ from most mills is 0.45% , is it acceptable. What is the consequence if we use it.

Regards,
Darren

 

[SJones]

1. NACE MR0175 does not contain the term 'moderate sour service.' Service is either sour, or it is not.
2. NACE MR0175 does not contain such detailed compositional requirements for A516
3. Depending on thickness, good quality plate mills will generally run up to about CEV of 0.43 as they mostly have to get the plate through a HIC test

It appears that the requirements you have are from an end user's specification. Would this plate be used to fabricate a split tee fitting for a pipeline hot tap by any chance?

If the specification says CEV 0.38, you will have to come to an arrangement with the owner of the document if such a value cannot be met.

Steve Jones
Corrosion Management Consultant

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

All answers are personal opinions only and are in no way connected with any employer.