Sulfuric acid (H₂SO₄) is a strong mineral acid. It is soluble in water at all concentrations. The corrosion rate in high temperature sulfuric acid is magnitudes lower than the corrosion rates of Hastelloy, titanium and zirconium. Sulfuric acid in concentrations between 10% and 90% is known to be especially corrosive.

Corrosion in diluted Sulfuric Acid
In diluted sulfuric acid (less than 10% sulfuric acid) the aggressiveness of the acid is limited, so austenitic and duplex steels and to some extend titanium may be a cost efficient option in the low temperature range. At temperatures above 100_°C more corrosion resistant materials like Tantaline or Hastelloy grades may be required.

Corrosion in Sulfuric Acid in the Concentration Range 10-90%
Sulfuric acid in concentrations between 10% and 90% is known to be especially corrosive. Common type metals like titanium and Hastelloy c-276 will show rapid corrosion in sulfuric acid at temperatures lower than 100_°C. Very few materials including Tantaline and exotic metals like Zirconium and Tantalum materials can be applied above the sulfuric acid boiling point. Tantaline is by far the most economical option. Tantaline will further maintain its corrosion resistance above the boiling point independent on the concentration up to 99%, whereas Zirconium will lose its corrosion resistance in sulfuric acid at concentration above approximately 75%.

Corrosion in Concentrated Sulfuric Acid
Concentrated sulfuric acid (water free) is less corrosive than water containing sulfuric acid and iron based alloys can shows in general good corrosion resistance in concentrated sulfuric acid. Silicon cast iron show low corrosion rates in 99% sulfuric acid, but will suffer from corrosion cracking when in SO₃ containing concentrated sulfuric acid (oleum). Depending on temperature austenitic stainless steels can be applied in oleum.