Выражение встречается в следующем контексте:
Measure Cr in carbon steel for evaluating flow accelerated corrosion (FAC)

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Вот Вам объяснение на англ.:

Most cooling and boiler systems are constructed of carbon steel, a material that is very prone to corrosion when it comes into contact with water. While the water-treatment industry has developed many products to retard that corrosion, it is important to recognize that boilers and cooling systems are very dynamic. The success or failure of any chemical treatment program is highly dependent upon the balance between two opposing processes: a chemical treatment program that forms a stable protective surface, and a flow that is continuously trying to remove it.