Corrosion failure analysis of the flow plate, which is one of the accessories of the plate heat exchanger in a district heating system, was performed. The flow plate is made of 316 stainless steel, and water at different temperatures in the flow plate exchanges heat in a non-contact manner. The flow plate samples in which water mixing issues occurred were collected. Corrosion-induced pits, oxides, and contaminants were observed at locations where two plates are regularly in contact. The EDS analysis of the surface oxides and contaminants revealed that they were composed of carbon, silicon, and magnesium, which came from chemical adhesives. The IC/ICP analyses showed that the concentration of chloride ions was 30 ~ 40 ppm, which was not sufficient to cause corrosion of stainless steel. In the crevice, a local decrease in dissolved oxygen occurs along with an increase in chloride ions, thus forming an acidic environment. These environments destroyed the passive film of stainless steel, resulting in pits. Moreover, contaminants formed a narrower gap between the two metal plates and inhibited the diffusion of ions, thereby accelerating crevice corrosion.

송민지 ( Min Ji Song )

최가현 ( Gahyun Choi )

채호병 ( Hobyung Chae )

김우철 ( Woo Cheol Kim )

김희산 ( Heesan Kim )

김정구 ( Jung-gu Kim )

이수열 ( Soo Yeol Lee )

Corrosion Science and Technology

판형 열교환기 전열판의 부식 파손 분석

板式换热器换热板腐蚀损坏分析

판형 열교환기 전열판의 부식 파손 분석

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Journal Info

Category	Quartile
ELECTROCHEMISTRY	4