WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
(OP)
1. I am in search of a WPS for welding 11 mm thick pipe of A335 P22 with a pipe of HP Nb Modified material (35% Cr & 25% Ni) in the convection zone of ethylene furnace with zone service temperature at approx.900 Deg C.
2. Do I need to go for PWHT in this case?
This is urgent. Please help.
2. Do I need to go for PWHT in this case?
This is urgent. Please help.





RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
According to Section I, no PWHT is required for Grade P22 pipe that is 16mm or less at the weld region. I would use a preheat of 400 deg F with Inco Weld A filler metal. Perform a Liquid PT after the completion of the weld.
Here is an interesting paper on the subject of repairability of the heat resistant stainless steel castings.
http://www.aws.org/wj/supplement/WJ102010_210.pdf
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
Thanks... In our case.. the thickness is approx. 11 mm and at the weld it would be around 13 mm. which is the threshold limit of carryinbg out PWHT for CR Mo steel ( P22) as per ASEM b31.3 table 331.3.2.
since it is dissimlar metal joint with HP Nb mod. material, shoud we condier PWHT in thsi case.
Please comment.
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
If you are following minimum code requirements, you do not need to PWHT the P22 base material in the weld region. The dissimilar material does not require PWHT because it is a heat resistant stainless steel.
Now, if the P22 material was cold formed or strained with no post-forming thermal treatment near the weld region, I would PWHT. Otherwise, if the material has not been cold worked or cold strained, no I would not perform PWHT.
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
Waiting for your response for PWHT on the above information gievn by me regarding service temp of F 22 material that i sto be welded with HP Nb Mod.
Plz. comment.
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
I would not PWHT.
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
We got some WPS from elsewhere that suggests PWHT on this dissimilar metal joint. Pl. Note that F22 (aged 15 yrs.) to be welded with HP Nb mod 35% Ni & 25% Cr (New).
Wall Thickness of weld portion is 11 mm.
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)
RE: WPS A335-P22 to HPNB Modified (35% Cr, 25% Ni)