10% NaOH, corrosion mechanism of alkali pumps
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The situation is as follows: The pump uses 10% NaOH at 50°C; the pump body and impeller are made of carbon steel, while the pump shaft is made of martensitic stainless steel. After ten years of operation, all three components have suffered corrosion to varying degrees. Experts, please explain the mechanism of this corrosion
The pump can last for ten years; its lifespan is quite good.
It’s worked pretty well; after ten years, the corrosion isn’t that severe. I would like to ask the original poster: what material are the inlet and outlet pipes of the alkali pump made of? Similar to your situation, the pump has been in use for six years and is functioning fine for now, but the seamless steel pipes at the inlet and outlet as well as the valves are suffering from frequent corrosion and damage
Can it last 10 years? It’s not called corrosion, right? ?
Carbon steel will work fine. Do you have many particles?
Compared to acids and salts, alkalis cause less corrosion; the corrosion mechanism of alkalis is alkali embrittlement
Carbon steel is sufficient for caustic soda. More durable than 304 at room temperature
It shouldn’t be the alkali embrittlement corrosion mechanism; the temperature isn’t high enough. Look for other reasons