FN in stainless steel piping

[Corgas]

Dear Colleagues, I need your opinion(s) one more time.

Recently I came across some new welds in stainless steel piping (built to ASME B31.3) with some degree of magnetism.

I have not used ferrite scope yet, but I will very soon. I've requested WPS/PQR to determine FN according to WRC-1992 FN diagram.

I know that ASME Section II, part C A6 pretty much describes what WRC established and from my previous life most refiners consider acceptable FN between 3 & 11.

Question 1) Does ASME B31.3 address ferrite content in weld deposits?

Question 2) If I find a FN > 11. What impact will have on corrosion properties and cryogenic properties?

Any links will be greatly appreciated.

Thanks,

Corgas

 

[SJones]

1)Not specifically, hence the coverage in API RP 582

2)The implications for in service performance are discussed in the SFA consumable specifications such as SFA-5.9, clause A.7. The corrosion performance will depend upon the environment to which the material is exposed.

Steve Jones
Materials & Corrosion Engineer

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

 

[EdStainless]

Please don't double post. Most of us are reading multiple forums.

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Plymouth Tube

 

[Corgas]

Thanks Steve.

Yes, SFA5.9 and SFA5.4 both describes same thing regarding ferrite.

1) is there a graph where it shows % ferrite Vs. toughness for austenitic SS?

1) What's the correlation between % ferrite Vs. Corrosion resistance (Ex: PREN) for austenitic SS?

Corgas