Abstract The shell and tube heat exchanger failed before 5 years of operation. The failure was caused by pits on the tube outside surface developing until its perforation. Inside the Cu-DHP tubes in soft temper a cooling agent circulated to cool down industrial water at the shell side from 16 to 4 °C. The cooled water was hard, rich in chloride ions with relatively low sulphate ions concentration and pH ranging from 4 to 7. The leaking tubes were subject to standard metallographic examination, hardness measurement, scanning electron microscopy and X-ray energy dispersion analysis. It was found that the tube damage was caused by erosion–corrosion induced by two factors: disturbed flow of water containing suspended solid particles and chemical composition of water rich in chlorides that resulted in loss of stability of protective cuprous oxide layer.
[1]
Gösta Wranglén.
An Introduction to Corrosion and Protection of Metals
,
1985
.
[2]
B. Poulson.
Complexities in predicting erosion corrosion
,
1999
.
[3]
John F. Ferguson,et al.
The pitting corrosion of copper
,
1994
.
[4]
Marc Edwards,et al.
Corrosion control on the basis of utility experience
,
1995
.
[5]
W. R. Fischer,et al.
Characterisation of reaction layers on copper surfaces formed in aqueous chloride and sulphate ion containing electrolytes
,
1994
.
[6]
R. Balasubramaniam,et al.
Microstructural characterization of copper corrosion in aqueous and soil environments
,
2005
.