Research on Application and Technology of Sulfur Dioxide Test Chamber in Industrial Corrosion Simulation

Introduction

With the acceleration of industrialization, sulfur dioxide (SO₂) from industrial emissions, acid rain and chemical industrial areas has become a major inducement for corrosion of metals and coating materials. In natural environments, the corrosion process is slow, long‑period and difficult to quantitatively evaluate, failing to meet the timeliness requirements of R&D, quality inspection and certification. The sulfur dioxide test chamber realizes accelerated corrosion tests by artificially simulating corrosion environments coupled with high‑concentration SO₂, temperature and humidity, reproducing long‑term service corrosion behaviors of materials within hours to days, and rapidly judging the corrosion resistance of materials.

As a main model of the series, the LISUN SQ‑010 sulfur dioxide test chamber adopts an integrated anti‑corrosion structure and high‑precision temperature‑humidity and gas concentration control. It meets mainstream domestic and international standards including GB, IEC, ISO, ASTM and DIN, and is widely used in corrosion reliability verification in hardware, electronics, automobiles, construction, aerospace and other fields, serving as key equipment for industrial product quality control.

Sulfur Dioxide Test Chamber SQ 010

Corrosion Simulation Principle of Sulfur Dioxide Test Chamber

The core of the sulfur dioxide test chamber is to simulate industrial sulfur‑containing humid atmospheric environments and realize accelerated corrosion through multi‑factor coupling:

• Gas environment: Stable‑concentration SO₂ gas is introduced into the chamber, which combines with water vapor in air to generate sulfurous acid (H₂SO₃), further oxidized into sulfuric acid (H₂SO₄), forming a strong‑acid electrolyte film on sample surfaces and triggering electrochemical corrosion.

• Temperature‑humidity driving: Temperature rise accelerates gas dissolution and chemical reactions; high humidity and condensation conditions strengthen the formation of electrolyte films and significantly increase corrosion rate.

• Acceleration mechanism: By increasing SO₂ concentration and controlling temperature‑humidity and test duration, the years‑long corrosion process in natural environments is compressed into several days in laboratories for rapid evaluation.

This method can effectively expose hidden defects such as pinholes in plating layers, insufficient coating adhesion, crevice corrosion of structures and contact sulfidation failure, providing basis for improvement of protective design.

Structure and Core Parameters of LISUN SQ‑010 Sulfur Dioxide Test Chamber

Structural Characteristics of Equipment
The LISUN SQ‑010 sulfur dioxide test chamber adopts an integrally formed working chamber made of imported corrosion‑resistant PP plates without welding gaps, preventing gas leakage and chamber corrosion with no aging or deformation during long‑term operation. It is equipped with U‑shaped titanium alloy high‑speed heating electric tubes featuring corrosion resistance, rapid temperature rise and uniform temperature. The system integrates a high‑precision gas concentration control system and a temperature cooperative control module, supporting automatic gas supplementation, real‑time concentration monitoring, test timing and cyclic operation, realizing full‑process intelligent control and reducing manual intervention and operational risks. Observation windows and waste gas treatment devices are installed on the chamber to ensure test safety and environmental‑friendly emission.

Core Technical Parameters
Parameters of the LISUN sulfur dioxide test chamber series represented by SQ‑010 are shown in the table below:

Table: Core Parameters of LISUN Sulfur Dioxide Test Chamber Series (SQ‑010 as Key Model)

Key control indicators:
• Temperature uniformity ≤±2℃, temperature fluctuation ≤±0.5℃ to ensure consistency of test environments.
• Sulfur dioxide concentration continuously adjustable at 25pphm or 0.1%~1% to meet requirements of different standards.
•  Supports cyclic test modes and alternating salt spray + SO₂ composite corrosion tests to adapt to complex working condition simulation.

Applicable Standard System

The sulfur dioxide test chamber must strictly comply with domestic and international standards to ensure result mutual recognition and compliance. Mainstream standards covered by LISUN SQ‑010 are as follows:

• National Standards: GB/T 2423.19‑2013, GB/T 2423.20‑2014, GB/T 2423.33‑2005, GB/T 9789‑2008, GB/T 5938‑2017, GB 25972‑2010.
• International Standards: IEC 60068‑2‑42/43, ISO 6988, DIN 50018, ASTM G87, ASTM B845, etc.

Different standards vary slightly in concentration, temperature‑humidity and test cycle, and LISUN engineers can provide precisely matched solutions.

Standard Test Process Based on LISUN SQ‑010 Sulfur Dioxide Test Chamber

Sample Preparation
Select metal materials, plating layers, coatings or complete machine parts, clean and degrease them, and record appearance, dimensions and functional parameters. Place samples evenly to ensure gas circulation and avoid mutual shielding.

Equipment Preparation
Check chamber tightness, heating system, gas pipelines and waste gas treatment devices. Introduce SO₂ gas with purity ≥99.9%, and set temperature, humidity, gas concentration and test duration.

Parameter Calibration
Calibrate temperature and SO₂ concentration after preheating and stabilization to meet standard requirements, then start automatic operation to enter the corrosion test stage.

Test Process
The system performs gas filling, heating, humidification, timing and circulation according to set procedures. Monitor sample status through observation windows and record abnormal phenomena.

Result Evaluation
Exhaust and purify gas after tests and take out samples. Observe corrosion morphology, rust area, coating blistering/peeling, plating discoloration, contact resistance change, etc., grade according to standards and judge qualification.

Technical Advantages of LISUN SQ‑010 Sulfur Dioxide Test Chamber

• Reliable Anti‑corrosion Structure: Integrally formed PP working chamber and titanium alloy heating components feature acid corrosion resistance, no leakage and long service life.
• Excellent Control Precision: Closed‑loop control of temperature‑humidity and gas concentration ensures good data repeatability, meeting certification‑level test requirements.
• High Intelligence: Supports long‑term timing and cyclic operation with automatic gas supplementation, monitoring and shutdown, reducing labor costs.
• Strong Standard Compatibility: Covers mainstream domestic and international corrosion test standards, meeting multi‑scenario and multi‑standard test demands with one machine.
• Safety and Environmental Protection: Equipped with waste gas treatment and multiple safety protections to prevent gas leakage, complying with laboratory environmental and safety specifications.

Application Fields

The sulfur dioxide test chamber is core equipment for reliability verification of industrial products. LISUN SQ‑010 is widely applied in:
• Hardware and Metal Products: Detect corrosion resistance of plating layers for fasteners, bathroom hardware, decorative parts, etc., avoiding early rusting.
• Electrical and Electronic Products: Evaluate sulfidation resistance of connectors, relays, PCBs and contacts to prevent contact failure.
• Automotive and Rail Transit: Verify durability of body coatings, chassis parts and interior metal components in acid rain and industrial atmosphere.
• Building Materials: Test aluminum profiles, coatings and steel structure anti‑corrosion layers to ensure long‑term outdoor service safety.
• Third‑party Testing and Certification: Provide compliant test data for CQC, CE, UL and other certifications to support product market access.

Conclusion

The sulfur dioxide test chamber is key inspection equipment for simulating industrial sulfur‑containing corrosion environments and accelerating evaluation of sulfide corrosion resistance of materials. With high‑precision control, reliable anti‑corrosion structure, intelligent operation and full standard coverage, the LISUN SQ‑010 sulfur dioxide test chamber can stably reproduce corrosion environments, quickly identify material and structural defects, and provide scientific and accurate corrosion resistance basis for industrial equipment, building materials, hardware products and electronic components.

Against the background of continuously improving quality and reliability requirements for industrial products, conducting corrosion tests with standardized and high‑precision sulfur dioxide test chambers is of important engineering significance and application value for optimizing protective processes, extending product service life, reducing service risks and supporting certification access.