Sulfuric Acid Corrosion
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 Corrosion in Sulfuric Acid (H2SO4)


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> Corrosion in Diluted Sulfuric Acid (0-10%)
> Corrosion in Sulfuric Acid (10-90%)
> Corrosion in Concentrated Sulfuric Acid
> Sulfuric Acid Iso Corrosion Curves
> Sulfuric Acid Corrosion Tables
> Tantaline Solultion in Sulfuric Acid



> See enginering evaluation of Hastelloy, titanium, zirconium and Tantaline in hot sulfuric acid

Tantaline has proven to be the most reliable material available for hot sulfuric acid corrosion media.

The corrosion rate of Tantaline in sulfuric acid is negligible in any concentration from 0 to 99% up to a temperature of at least 150°C. 

In sulfuric acid at temperatures above 150°C the corrosion rate of Tantaline will have to be considered, but the corrosion rate of Tantaline in high temperature sulfuric acid is magnitudes lower than the corrosion rates of Hastelloy, titanium and zirconium. Tantaline has been applied sucessfuly for more than 15 years in critical customers applications.


Sulfuric Acid Iso Corrosion Curves 

This iso corroion curve shows the relative corrosion resistance of several specialty alloys and exotic metals in various concentrations and temperatures of sulfuric (sulphuric) acid (H2SO4).  It can be seen that the corrosive nature of sulfuric acid, as with most acids, is highly dependent on the temperature and concentration of the solution

 Sulfuric Acid Corrosion Data

 Click to get an audio explanation of this chart...

Corrosion in diluted Sulfuric Acid (0-10%)

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 100C more corrosion resistant materials like Tantaline or Hastelloy grades may be required.



Corrosion in Sulfuric Acid in the Concentration Range 10% to 90%

Sulfuric Acid in concentrations between 10 and 90% is known to be especially corrosive. Common type specialty metals like e.g. 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) sulfuric acid 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.


Sulfuric Acid Corrosion Tables

H2SO4 Corrosion Data
Table: Corrosion Performance of Materials in Sulfuric Acid at Concentrations from 10 to 90% and Temperatures of 50, 100 and 150C

Tantaline Solutions for Sulfuric Acid Service 

Tantalum is superior for handling sulfuric acid at elevated temperatures. A large heater services have been installed in plants for the re-concentration of diluted sulphuric acid arising from metal pickling, oil refinery operations and from petrochemical processes producing alcohols and ketones. 

Tantaline offers a large standardized product range including valves, thermowells, fittings and fasteners for sulfuric acid service. Tantaline Treatment  may further be used for customer specific design for heat exchangers, heaters, coolers, reactors and pump parts for sulfuric acid applications.

Tantaline offers real solutions to your most challenging corrosion demands in sulfuric acid. 

Limitation of Tantaline in Sulfuric Acid Service

At very high concentrations of sulfuric acid (>98%), the corrosion performance of tantalum as well as Tantaline will decrease due to existence of "free" SO3. Thus Tantalum metal is in general not suitable for fuming sulfuric acid (oleum).

*) Hastelloy is a trademark of Haynes International. Tantaline is a Traname of Tantaline.

Guide to Sulfuric Acid (H2SO4) Resistant Products
 ► Agitators 
 ► Autoclaves 
 ► Bellows 
 ► Couplings  
 ► Earthing Rings 
 ► Expansion Joints 
 ► Fasteners  
 ► Fittings, Pipe 
 ► Fittings, Tube 
 ► Flanges  
 ► Grounding Rings 
 ► Heat Exchangers 
 ► Instrumentation  
 ► Laboratory Reactors  
 ► Level Sensors  
 ► Orifice Plates  
 ► Pipe Fittings 
 ► Pumps 
 ► Static Mixers 
 ► Stirrers  
 ► Thermowells 
 ► Tube Fittings 
 ► Valves 
Performance Data
See Tantaline vs Coatings in:
 > Chlorine Gas
 > Sulfuric Acid
 > Liquid Bromine

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