Welding defected in electric resistance welds used to fabricate steel pipe have been alleged. ERW defects have been alleged to have caused pipe leakage and failure in air conditioning condenser pipe in several commercial buildings. JEI metallurgical has been requested to conduct an engineering evaluation of several of these failures.
A view of external surface of failed ER weld seam is shown in Photograph A
Photograph A – Corrosion perforation of ERW seam
A view of the inside surface with ER weld seam completely trenched by corrosion is shown in Photograph B
Photograph B – Overall view of inside pipe surface with ER weld completely corroded.
Metallographic mount of sample cut from non-perforated ER weld seam is shown in photograph C.
Photograph C – close up view of ER weld seam partially corroded
Close up view of metallographic mount showing selective heat affected zone corrosion of the ER weld seam and adjacent heat affected zone is sown in photograph D
Photograph D – close up view of metallographic mount showing heat affected zone corrosion in valleys next to ER weld seam
Metallographic mount proved that subject ER weld seam was not defective and corrosion was galvanic. Evidence of anaerobic SBR corrosion was observed on the inside surface of the failed pipe.
