George Pantazopoulos, Athanasios Vazdirvanidis, Andreas Rikos and Dionysios Skarmoutsos
The purpose of this paper is to identify the corrosion failure mechanism of a Cu tube in a hydraulic installation and recommend corrective actions to improve the reliability of…
Abstract
Purpose
The purpose of this paper is to identify the corrosion failure mechanism of a Cu tube in a hydraulic installation and recommend corrective actions to improve the reliability of the entire unit.
Design/methodology/approach
Failure investigation process includes mainly stereo-, light optical microscopy and scanning electron microscopy as the main analytical tools for material characterization and root-cause analysis.
Findings
The investigation findings, obtained by corroded surface analysis and metallographic evaluation in transverse sections, suggest strongly that the failure was caused by the operation of Type I pitting corrosion mechanism initiated from the inner side and propagated towards the outer tube surface, assisted by the flowing medium composition.
Originality/value
This paper deals with an applied failure analysis/case history, summarizes the stages involved in the mechanism of pitting corrosion Type I, taken place in cold water systems together with the main parameters and corrosive species that enhance corrosion rates, shortening pipeline operation life.
Details
Keywords
Athanasios Vazdirvanidis, Sofia Papadopoulou, Spyros Papaefthymiou, George Pantazopoulos and Dionysios Skarmoutsos
The purpose of this paper is to address the main aspects of ant-nest corrosion failure mechanism of a Cu tube in heating ventilation and air-conditioning (HVAC) installations and…
Abstract
Purpose
The purpose of this paper is to address the main aspects of ant-nest corrosion failure mechanism of a Cu tube in heating ventilation and air-conditioning (HVAC) installations and analyze the possible root causes through various case studies presented.
Design/methodology/approach
Failure investigation process includes mainly stereo-, light optical and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy for elemental microanalysis, as the main analytical techniques for material characterization and root-cause analysis.
Findings
The investigation findings, obtained from corrosion products’ analysis in conjunction to metallographic evaluation in transverse sections, illustrate the principal characteristics (“fingerprints”) of ant-nest (formicary) corrosion mechanism.
Originality/value
This paper which deals with the presentation of applied failure analysis/case histories’ investigation, summarizing the main aspects of an important and insidious type of Cu corrosion, taken place in HVAC installation systems and, on the other hand, presenting a complementary analysis of the chemical processes involved in the progressive failure mechanism constitutes an integrated approach, aiming to become a concise contribution to this subject.