Corrosion is one of the main characters of Al microchannel heat exchanger.In the present study

standard seawater acidified test (SWAAT)was carried out in microchannel heat exchangers with folded tube and traditional extruded tube

then the performance test and electron metallography analysis were carried on the test samples before and after the corrosion.The result showed that the performance of the sample with folded tube was much better than that with traditional extruded tube after SWAAT.According to the electron metallography analysis

for the test sample with extruded tube

the connection of fins and tubes was damaged first in the SWAAT.Obvious fin debonding occurred after 14 d of SWAAT

and leakage happened on the tube at main body after 28 d of SWAAT.In contrast

the fins of the test sample with folded tube were damaged first in the SWAAT

and no any fin debonding or leakage on the tube occurred after 49 d of SWAAT.The long-term performance of folded tube is better than that of extruded tube.