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2205 Duplex Steel Chloride Corrosion Resistance Test for Desulfurization Towers

29 May 2026 | by NaDong Stainless steel

1. Introduction: Harsh Corrosion Environment of Desulfurization Towers

Flue gas desulfurization towers are core equipment for industrial exhaust treatment.

The internal operating environment features high temperature and high humidity.

A large amount of chloride ions exist in desulfurization slurry and circulating water.

Chloride enrichment easily causes pitting and crevice corrosion on steel surfaces.

Ordinary carbon steel and 304 stainless steel suffer rapid corrosion damage.

Frequent equipment leakage and shutdowns increase operating costs.

2205 duplex steel is widely selected for desulfurization tower lining and structural parts.

Professional chloride corrosion resistance tests verify its practical adaptability.

2. Why Chloride Corrosion Occurs in Desulfurization Systems

2.1 High Chloride Ion Concentration

Industrial flue gas carries chloride impurities into the slurry system.

Continuous water circulation leads to constant chloride accumulation.

Local concentration far exceeds the tolerance of ordinary stainless steel.

2.2 High Temperature and Acidic Environment

Tower internal temperature accelerates electrochemical corrosion reactions.

Acidic desulfurization medium further weakens metal passivation films.

Corrosion spreads quickly once surface protection fails.

2.3 Alternating Wet and Dry Conditions

Wet-dry alternation forms concentrated chloride liquid films.

It induces localized pitting and intergranular corrosion on steel.

3. Advantages of 2205 Duplex Steel for Desulfurization Conditions

3.2 Dual-Phase Microstructure

Balanced austenite and ferrite dual-phase structure.

Improves overall structural stability under corrosive conditions.

3.2 High Chromium and Molybdenum Content

Alloy components form dense and stable passivation films.

Effectively blocks chloride ion penetration and erosion.

3.3 High Mechanical Strength

Higher strength than common austenitic stainless steel.

Resists structural damage caused by long-term corrosion and scouring.

4. Standard Chloride Corrosion Test Methods

4.1 Salt Spray Corrosion Test

Simulate high-concentration chloride salt spray environment.

Continuously observe surface pitting, rusting and peeling status.

Record corrosion rate within the specified test cycle.

4.2 Immersion Corrosion Test

Soak 2205 steel samples in simulated desulfurization slurry.

Set different chloride concentrations and temperature gradients.

Test weight loss and surface morphology changes.

4.3 Electrochemical Performance Test

Detect passivation film stability and corrosion current density.

Evaluate the ability to resist chloride ion breakdown.

Obtain accurate anti-corrosion performance data.

4.4 Wet-Dry Alternating Aging Test

Simulate real tower operation wet and dry cycles.

Verify long-term anti-corrosion durability of 2205 steel.

5. Core Test Results and Analysis

5.1 Low Corrosion Rate

2205 steel shows almost no uniform corrosion in high chloride media.

Corrosion rate is far lower than 304 and 316L stainless steel.

5.2 Strong Pitting Resistance

No obvious pitting or pore defects on sample surfaces.

The passivation film maintains stability under chloride erosion.

5.3 Stable High-Temperature Performance

Even with rising temperature, anti-corrosion performance declines slightly.

Adapts to variable temperature working conditions of desulfurization towers.

5.4 Long Service Life Potential

Accelerated aging tests prove long-term operational stability.

Greatly extends maintenance and replacement cycles.

6. Practical Engineering Application Value

Qualified test results support reliable material selection for desulfurization towers.

2205 duplex steel reduces equipment corrosion failure risks.

Cuts frequent maintenance and shutdown loss costs.

Improves the overall operational stability of flue gas desulfurization systems.

Suitable for tower inner walls, slurry pipelines and spray components.

7. Construction and Operation Notes

Avoid surface scratch damage during processing and installation.

Prevent welding defects that cause local corrosion sensitivity.

Regularly clean surface chloride deposits in daily operation.

Timely repair damaged passivation layers to ensure long-term protection.

8. Conclusion

Desulfurization towers face severe chloride corrosion and complex working conditions.

Ordinary stainless steel materials cannot meet long-term stable operation demands.

A series of chloride resistance tests confirm the excellent performance of 2205 duplex steel.

Its dual-phase structure and high-alloy formula effectively resist chloride pitting corrosion.

It has become the preferred material for key parts of medium and large desulfurization towers.

Standard corrosion testing provides accurate basis for material selection and engineering design.

Promoting 2205 steel application helps reduce industrial desulfurization equipment failure rates and comprehensive operating costs.

The above content was generated by AI assistance.

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