Abstract
Dewpoint corrosion of air-heater tubes on marine boilers was investigated, with corrosion-resistant steel tubes intruded, on some ships. The following results were obtained in the test.
1) The tubes failed by corrosion amounted to 20-30% of the whole tubes at the air heater on one ship, and 25-30% on another.
2) Mean corrosion rate of lead-coated tubes is about one half of that of carbon steel tubes, but some lead-coated tubes were perforated by corrosion after six months.
3) Corrosion-resistant steel tubes of Cor-Ten series were much better than the two above, and were not perforated by corrosion even after two years.
