NACE MR-01-75 Question
NACE MR-01-75 Question
(OP)
NACE MR-01-75 says that maximum allowable NI content for alloy steels in sour service is to be less than 1%. Is there a restriction on weld metal composition with regard to NI content under the same scenario? Is this also set at a max of 1%?





RE: NACE MR-01-75 Question
ANSI/NACE MR0175/ISO 15156-2:2009, Clause A.2.1.4 allows the following:- Welding consumables and procedures that produce a deposit containing more than 1 % mass fraction nickel are acceptable provided successful weld SSC qualification by testing in accordance with Annex B(of MR 0175/ISO 15156) is met.
However the default rule is also 1% Max Nickel in the weld metal, as described in many welding consumable manufacturer's consumable specification sheet.
Apparently few years ago TWI intiated the following Group Sponsored Project(see the atatchment), titled as : "Raising the Acceptance Level for Nickel in C-Mn Welds for Sour Service". If the other members could shed some lights on this subject it would be very well appreciated.
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario, Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
RE: NACE MR-01-75 Question
http://www.weldinguide.com/gdanastasiadis/viewtopi...
RE: NACE MR-01-75 Question
Note, OCTG grades T95, C105,C110, (sour service) use very low limits on Ni and Mn and use very high tempering temps like 1400F.
RE: NACE MR-01-75 Question
Interestingly, Ni at these levels also has a surprisingly negative effect on low temperature impact strength values. The segregation idea may be contributing to both.
rp