Material selection for corrosion resistance at room temperature for 98% concentrated sulfuric acid
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98% concentrated sulfuric acid is transported at room temperature using a metering pump at a rate of 1 ton per day. The inlet filter is made of 304 stainless steel, and corrosion does not occur after just one week. There is a large amount of sediment at the bottom of the tank under normal pressure, and it appears black in color. May I ask, does this operating condition indicate that the material is quite resistant to sulfuric acid corrosion?
Generally, carbon steel can be used for sulfuric acid concentrations of over 80%. We use 98% sulfuric acid as well, and our carbon steel pipes have worked fine for 3 years with no problems.
Teflon or carbon steel can both be used.
At room temperature, carbon steel works better with concentrated sulfuric acid
When used in sulfuric acid media, stainless steel has better corrosion resistance than carbon steel; however, 316 is typically used. The corrosion of steel by concentrated sulfuric acid depends mainly on three factors: concentration, temperature, and flow rate. In your case, could it be that the flow rate is too high or that turbulence is occurring at the filter location? It is generally better to keep the flow rate below 0.9 m/s.
Are there any other impurities in sulfuric acid?
Plain carbon steel will do, but corrosion and leakage usually occur at the welding areas. To avoid corrosion issues, we applied SD8005 carbon nanopolymer material to the weld areas in advance, and the result was good.
Carbon steel is sufficient for over 85% of sulfuric acid applications