Technical gazette, Vol. 24 No. 4, 2017.
Original scientific paper
https://doi.org/10.17559/TV-20170112142442
Corrosion damage of seam welded galvanized hot water pipelines
Dražen Živković
; University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Ruđera Boškovića 32, 21 000 Split, Croatia (EU)
Nedjeljko Mišina
; University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Ruđera Boškovića 32, 21 000 Split, Croatia (EU)
Petar Ljumović
; University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Ruđera Boškovića 32, 21 000 Split, Croatia (EU)
Abstract
The aim of this paper was to determine the cause of corrosion damage on hot water seam welded galvanized pipelines. Chemical analysis of the pipeline samples as well as their microstructure analysis has been undertaken. Visual inspection of samples of the internal surface of the pipelines was conducted, as well as the chemical analysis of water samples from specific regions of the hot water pipeline. The analysed samples came from the damaged pipeline, replaced pipeline and also from the new, unused pipelines and compared. The effects of the locally developing corrosion processes have been investigated. The influence of the welded joint structure and its heat-affected zone on the corrosion process intensity was analysed. The synergistic effect of zinc from the pipeline coating and the copper ions from the heat exchanger on the water systems corrosion development has been analysed. The fundamental preconditions of formation and development of various copper corrosion types were investigated, as well as the affecting influence of copper ions. The influence of hot water temperature against corrosion processes development was inspected. The testing results have showed that the corrosion process was generated due to the increase of copper concentration in hot water pipeline.
Keywords
copper corrosion; galvanized pipeline corrosion; hot water pipeline
Hrčak ID:
185440
URI
Publication date:
31.7.2017.
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