Failure Analyses of Air Preheating Tube of a Heating Furnace and Its Improvement Measures

The failure reesons of an air preheating tube were investigatal by using microstructure examination,X-ray diffraction and XPS tests.The results showed that the failure causes of the tube were the co-action of the suffuric acid dew point corrosion and high tempreture fired gas corrosion.Some improvement measures put forward.