There's no genuine reason for this PQR to fail, if all the concerned welding was done properly. Nickel base alloys are well designed to pass CPT test @ 25 Deg C with 24 hrs boiling, especially G-48A test. Where was the failure, weld or base metal. Incoloy 825 is of leaner chemistry than 625 weld metal(assuming this consumable was used). Can you share the welding data ???
G-48 specifies 5 types of pitting and crevice corrosion tests.
Method A is designed to determine the relative pitting resistance of stainless steels and nickel-base, chromium bearing alloys, whereas Method B can be used for determining both the pitting and crevice corrosion resistance of these alloys.
Methods C, D, E and F allow for a ranking of alloys by minimum (critical) temperature to cause initiation of pitting corrosion and crevice corrosion, respectively, of stainless steels, nickel-base and chromium-bearing alloys in a standard ferric chloride solution.
What DNV specification was followed for testing. Is it OS F 101-2010 by any chance??
Appreciate your reply.
Thanks
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of ali firdauz
Sent: Friday, November 23, 2012 2:59 AM
To: materials-welding@googlegroups.com
Subject: [MW:16005] Buttering weld by using Inconel 625 filler on inner of pipe of UNS N08825
Currently i'm developing WPS of buttering weld on inner pipe (14.3mm DNV gr450 + 2.5mm UNS N08825). I sent them to mechanical testing base on DNV spec for incoloy clause. Unfortunately we failed for G48 method A.
Right now I try to find out the consequence of failure.. I not sure how the methodology to perform buttering weld, Is it required purging with purify argon? Since we are using GTAW process with flat position. Maybe the failure because of heat?We did control the heat input less than 1kj/mm and temperature below 50 degree C. The testing according to G48 with method A and temperature at 22 degree C for 24Hrs.The specimen prepared 75mmX50mmX 2.5mm(CRA thickness). The issue is the pitting appeared at liner area.(between carbon steel and CRA)
Please advise.
Thank you.
Best Regards,
AFA
-- To post to this group, send email to materials-welding@googlegroups.com
To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
Comments