Joined carbon steel clad with UNS 6625
Joined carbon steel clad with UNS 6625
(OP)
Hello Guys, i have a question regarding the weld beatween a pipe carbon steel cladded with uns 6625 wall thk 28mm. The consumable required is UNS 6625 . My client required pwht according to B. 31.3 but i would not to do pwht because the uns 6625 not required this procedure. The weld literature do not recomanded the pwht for joint welded with UNS 6625. I have proposed to increase the preheat permitted by ASME VIII but i'am not sure that to will be approved. Do you have some suggestion? Do you know if there are Asme interpretation?
Thanks Marcello
Thanks Marcello





RE: Joined carbon steel clad with UNS 6625
If you doing it with all 625 then you may need to put a butter pass on the parts, then PWHT, then weld the joint in 625.
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P.E. Metallurgy, Plymouth Tube
RE: Joined carbon steel clad with UNS 6625
RE: Joined carbon steel clad with UNS 6625
The immediate concern after PWHT could be the failure of bend test due to Carbide precipitation & reduced ductility. You may refer this document for overall guidance.
E-ER-NiCrMo3 is usually the consumable of choice, however stringency over and above ASME Sec II, Pt-C may be required.
Thanks.
http://www.nipera.org/~/Media/Files/TechnicalLiter...
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
Ontario,Canada.
ca.linkedin.com/pub/pradip-goswami/5/985/299
RE: Joined carbon steel clad with UNS 6625
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.
RE: Joined carbon steel clad with UNS 6625
RE: Joined carbon steel clad with UNS 6625
i am agree with you and @pradipgoswami.I must be in compliance with ASME Code + B31.3 e for this kind of wall thk (28mm) the pwht is mandatory( except for Table 331.1.3), the pwht is not required for the type of process. Anyway my client ask me to do PWHT AT 621°C minimun for 2h and qualify a PQR whith ASTM G48 Pr.A, PMI, Ferrite Test. I have already proposed your opinion but my client writes me that delete the pwht only if i show that Carbon Steel joined with UNS6625 without pwht is permitted in ASME or B31.3 or other official code. I have tried to demostrate it with old pqrs qualified without pwht with good result but is not enought. I think will be very difficult to obtain something. Anyway thank you for your opinion.