clay87
Mechanical
- Jul 19, 2010
- 91
We are in a situation where we would like to relax a requirement (in our equipment specification) for PWHT following any welding on a NiAlBr pump impeller.
The weld repair is just for dimensional restoration of an impeller bore. Base metal material is B148 C955. Weld filler is CuNiAl (Ampcotrode 46). Environment is slightly brackish water.
We haven't had any corrosion/dealloying problems with NiAlBr (C955) castings or with any of our weld metals. However, we have seen de-alloying of AlBr (C954) castings in this environment. Also, in our experience and application, de-alloying of AlBr has occurred whether or not the castings have PWHT.
Does anyone have any input regarding PWHT of NiAlBr for corrosion resistance?
Thanks in advance!
The references I have reviewed include:
Copper Development Association, Publication No 85, 1988
Nickel Development Institute, Reference Book. Series No 11 004, 2nd ed, 1995
US Naval Applied Science Laboratory, Project 930-76, 1967
DOD-STD-2185, NAVSEA 0991-LP-023-3002, 1982
The weld repair is just for dimensional restoration of an impeller bore. Base metal material is B148 C955. Weld filler is CuNiAl (Ampcotrode 46). Environment is slightly brackish water.
We haven't had any corrosion/dealloying problems with NiAlBr (C955) castings or with any of our weld metals. However, we have seen de-alloying of AlBr (C954) castings in this environment. Also, in our experience and application, de-alloying of AlBr has occurred whether or not the castings have PWHT.
Does anyone have any input regarding PWHT of NiAlBr for corrosion resistance?
Thanks in advance!
The references I have reviewed include:
Copper Development Association, Publication No 85, 1988
Nickel Development Institute, Reference Book. Series No 11 004, 2nd ed, 1995
US Naval Applied Science Laboratory, Project 930-76, 1967
DOD-STD-2185, NAVSEA 0991-LP-023-3002, 1982
