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The main reason for the rusting of water-based coatings during the drying process of flash rust test strips is that water-based coatings are conductors. Generate current between different regions with positioning differences. Under the combined action of water and oxygen, metal substrates undergo corrosion.

The principle of producing flash rust is very complex, but it can be summarized as relatively simple. It is related to water, oxygen, and metal. The longer the contact time between the three, the more likely it is to produce flash rust.

When it comes to the causes of flash rust, how can we prevent it? There are actually many ways to prevent flash rust, such as accelerating drying to increase its drying speed and facilitate the rapid evaporation of moisture.

The second one is thin spraying, which also accelerates the evaporation of water.

The second is to increase the pH value of the coating. The higher the pH value, the less likely flash rust is to occur.

The fourth and most efficient method is to add anti flash rust additives, which have two main mechanisms of action. The first major category is the consumption of dissolved oxygen, which involves consuming the oxygen inside.

For example, there are some anti flash repair agents that contain structures such as sodium sulfite or hydrazine, which can consume dissolved oxygen in water. After reducing the concentration of oxygen, it plays a good buffering role. The second mechanism is the ability to form insoluble complexes with metal ions generated by the substrate. Settling on the surface of the metal, it blocks the electrochemical decomposition process of the cathode and anode, achieving the effect of slowing down moisture. We have several good anti flash repair additives, which are very excellent and even have good anti flash rust effects for submerged arc welding. Adding 0.5% has a good anti flash rust effect. If added to 2% and combined with a small amount of sodium nitrite, most of the scattered rust in submerged arc welding can be suppressed.