Investigation of Acid Attack on Boilers and the Effect of Repeated Acid Cleaning on the Metal

The results of this investigation have served to clarify some of the controlling factors of acid attack which were not generally recognized. The investigation shows that stressed metal is more readily attacked by inhibited acid than stress-relieved metal. With a knowledge of the controlling factors, such as temperature, acid strength, and contact time, the operator can acid-clean boilers with a reasonable assurance that corrosion or metal attack will be reduced to a minimum.