Corrosion comparison: Mitreh Cold scale remover solution (MDA0102) vs. hydrochloric acid
1404/08/24
What is the Langelier Index? A Complete Guide to Predicting Water Sedimentation and Corrosion
1404/08/21
Measuring Carbonate and Bicarbonate in Water: A Complete Guide to Alkalinity Control
1404/08/19
Warning signs that indicate the need for chemical cleaning of the heat exchanger
1404/08/17
Local corrosion inhibitor
Localized corrosion inhibition
Localized corrosion occurs on metals covered by oxide layers. This can be caused by defects or breakage of the oxide layer. Attacking ions such as chloride cause the oxide layer to break down at weak points on the metal surface. In this case, most of the metal is in the oxide state while small localized areas of it are in the active state.
Localized corrosion will begin after the time required for the metal to interact with the aggressive environment has elapsed. This time is known as the initiation time for hole nucleation, which depends on the concentration of the oxide ions and the electrode potential of the metal. The origin of the holes depends on the presence of weak points in the surface oxide layer. At these points, corrosion products are formed at a higher rate than on the oxide surface.
Some mineral compounds reduce the rate of localized corrosion and increase the potential for failure. Some anions such as NO3–, SO2–, Cr2O7, H2PO4–, and OH– are inhibitors and prevent localized corrosion of iron and nickel. Inorganic inhibitors used to prevent localized corrosion are spoilage agents and include compounds that form insoluble salts on the metal surface. Nitrite and chromate are spoilage agents that slow down the rate of reduction or, in other words, cause the electrode potential to change to more positive values.
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Corrosion comparison: Mitreh Cold scale remover solution (MDA0102) vs. hydrochloric acid
1404/08/24What is the Langelier Index? A Complete Guide to Predicting Water Sedimentation and Corrosion
1404/08/21Measuring Carbonate and Bicarbonate in Water: A Complete Guide to Alkalinity Control
1404/08/19Warning signs that indicate the need for chemical cleaning of the heat exchanger
1404/08/17
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