FN in stainless steel piping
FN in stainless steel piping
(OP)
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
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





RE: FN in stainless steel piping
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
RE: FN in stainless steel piping
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Plymouth Tube
RE: FN in stainless steel piping
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