Selective Corrosion Attack at Brazed Joints
Persistent leakage was experienced from copper tube heaters which formed part of dairy equipment. Metallurgical examination of the brazed joints showed them to have suffered a preferential corrosion attack. This resulted in the phosphide phase of the brazing alloy being corroded away, leaving a weak, porous residual structure. The brazing alloy was of type CP 1 as covered by BS 1845. Header and tube materials were basically copper-nickel alloys for which the use of a phosphorus bearing brazing alloy is not recommended owing to the possibility of forming the brittle intermetallic compound, nickel phosphide. The use of a brazing...
Selective Corrosion Attack at Brazed Joints, ASM Failure Analysis Case Histories: Processing Errors and Defects, ASM International, 2019, https://doi.org/10.31399/asm.fach.process.c9001439
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