Research on Salt Spray Corrosion Testing Based on LISUN YWX/Q-010 Salt Fog Test Machine

Abstract
Salt spray corrosion is one of the main environmental factors leading to the failure of metal materials and various industrial products. The global economic loss caused by salt spray corrosion reaches hundreds of billions of US dollars every year. As a core testing equipment for simulating salt spray corrosion environments, the salt fog test machine can quickly evaluate the corrosion resistance of materials and products through accelerated corrosion tests, providing key data support for quality control and product research and development in industrial production. Taking the LISUN YWX/Q-010 salt fog test machine as the research carrier, this paper systematically expounds the basic principle, industry standards and test process of salt spray corrosion testing, analyzes the technical parameters and core advantages of this model in detail, and verifies its test accuracy with measured data, so as to provide practical reference for corrosion resistance testing in automotive, electronic, military and other industries.

1. Introduction
In scenarios such as marine environments, industrial plants and automobile driving, the protective coatings on the surface of metal materials and products are vulnerable to salt spray erosion. Chloride ions in salt spray have strong penetration, which can break through the oxide layer and protective coating on the material surface, undergo electrochemical reactions with internal metals, leading to material rust, performance degradation and ultimately product failure. By artificially simulating the natural salt spray environment, the salt spray corrosion test shortens the test cycle from several years in the natural environment to several days or weeks, realizing accelerated corrosion evaluation, which is an indispensable quality inspection method in the industrial field.

As a core product of LISUN Group, the LISUN YWX/Q-010 salt fog test machine (for details: https://www.lisungroup.cn/products/2269.html) has been verified by the market for more than ten years. It has the advantages of complying with multiple international and domestic standards, high test accuracy and convenient operation, and has been widely used in corrosion resistance testing of electronic components, auto parts, metal materials, military equipment and other fields. This paper will comprehensively analyze the technical points and practical applications of salt spray corrosion testing around this salt fog test machine.

2. Principle and Industry Standards of Salt Spray Corrosion Testing

2.1 Test Principle
The core principle of salt spray corrosion testing is to simulate the atmospheric environment containing chloride ions through a salt fog test machine, atomize sodium chloride solution to form uniform salt spray, and continuously or intermittently spray it on the surface of test samples. Chloride ions in the salt spray will be adsorbed in the pores and cracks on the sample surface, expel and replace oxygen in the oxide layer, convert insoluble oxides into soluble chlorides, destroy the passivation state of the material, and cause electrochemical corrosion. By observing the corrosion degree of the sample within a specified time (such as rust area, coating peeling, etc.), the corrosion resistance grade can be evaluated.

2.2 Industry Standards
Salt spray corrosion testing must strictly follow relevant international and domestic standards to ensure the authority and comparability of test results. The LISUN YWX/Q-010 salt fog test machine is fully compatible with a number of core standards, covering electrical and electronic, light industry, automotive, military and other industries, including:
Domestic standards: GB/T2423.17 “Environmental testing for electrical and electronic products – Part 2: Test methods – Test Ka: Salt mist”, GB/T10125 “Artificial atmosphere corrosion test – Salt spray test”, GB/T1771 “Paints and varnishes – Determination of resistance to neutral salt spray”, QB/T 3826 “Corrosion resistance test method for metal coatings and chemical treatment layers of light industrial products – Neutral salt spray test (NSS)”, etc.;

International standards: IEC 60068-2-11 “Environmental testing – Part 2-11: Tests – Test Ka: Salt mist”, ASTM-B117 “Standard Practice for Operating Salt Spray (Fog) Apparatus”, ASTM-B368 “Standard Test Method for Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing (CASS Test)”, ISO 9227 “Corrosion tests in artificial atmospheres – Salt spray tests”, etc.;
Military and automotive standards: MIL-STD-202 “DEPARTMENT OF DEFENSE TEST METHOD STANDARD ELECTRONIC AND ELECTRICAL COMPONENT PARTS”, GJB150 “Environmental test methods for military equipment”, ISO 16750-4 “Road vehicles – Environmental conditions and testing for electrical and electronic equipment – Part 4: Climatic loads”, etc.

3. Technical Characteristics and Parameters of LISUN YWX/Q-010 Salt Fog Test Machine

3.1 Core Technical Characteristics

The LISUN YWX/Q-010 salt fog test machine is fully designed to meet the testing needs of various industries, with three core advantages:
• Multi-mode test function: Supports three test modes including continuous spray, intermittent spray and programmable spray, and can realize neutral salt spray test (NSS), acetic acid salt spray test (AASS) and copper-accelerated acetic acid salt spray test (CASS), adapting to the testing requirements of different materials and products;
• High-precision control system: Adopts dual protection of mechanical over-temperature protection and electronic over-temperature protection, with temperature uniformity ≤ 2℃, temperature fluctuation ≤ ±0.5℃, and salt spray settlement rate stably maintained at 1-2ml/80cm²/h (average value of 16-hour test), ensuring the consistency of the test environment;
• Convenient operation and safety design: Equipped with stainless steel gas spring-assisted cover opening for labor-saving operation; equipped with multiple safety protection devices such as low water level alarm, over-temperature alarm and low air pressure alarm; at the same time, standard configuration of V-shaped groove and O-shaped round bar sample holder, adjustable angle of 20°±5°, suitable for samples of different shapes.

3.2 Key Technical Parameters

The detailed technical parameters of the LISUN YWX/Q-010 salt fog test machine are shown in the following table. Its size, volume, power and other indicators are optimized to balance test capacity and operational stability:

Parameter Category	Specific Value
Working chamber size	1200mm×800mm×500mm
Outer box size	1700mm×1150mm×1200mm
Working chamber volume	480L
Brine tank volume	32L
Power supply	Three-phase AC 380V/50HZ (60Hz customizable)
Rated power	2.5KW
Usable sample space	1000mm×600mm×300mm
Cover opening method	Stainless steel gas spring assisted
Working chamber temperature range	Room temperature ~ +55℃
Saturation barrel temperature range	Room temperature ~ +70℃ (heats and filters compressed air to reduce nozzle crystallization)
Temperature performance	Temperature uniformity ≤ 2℃, temperature fluctuation ≤ ±0.5℃
Salt spray settlement rate	1-2ml/80cm²/h (average value of 16-hour test)
Test type	Neutral test (NSS), acetic acid test (AASS), copper-accelerated salt spray test (CASS)
Safety protection devices	Low water level alarm, dual over-temperature protection (mechanical + electronic), low air pressure alarm
Air source requirement	Inlet pressure above 0.4Mp, two-stage pressure regulation, spray pressure 0.07~0.17Mp (adjustable)
Standard configuration	1 set of V-shaped/O-shaped rack, 2 bottles of sodium chloride reagent (500g/bottle), 1 piece of 5L plastic rust-proof bucket, 1 nozzle
Operating environment requirement	Ambient temperature 5℃~30℃, indoor ventilation, ambient humidity below 80%Rh

4. Salt Spray Corrosion Test Process and Measured Verification

4.1 Test Process
Taking the test of auto parts (galvanized steel sheet) as an example, the test process using the LISUN YWX/Q-010 salt fog test machine is as follows:
•  Sample preparation: Select 3 galvanized steel sheet samples with specifications of 100mm×50mm, wipe the surface oil with absolute ethanol, air dry naturally and mark;
•  Equipment commissioning: Inject 5% concentration sodium chloride solution into the brine tank, set the working chamber temperature to 35℃, saturation barrel temperature to 47℃, salt spray settlement rate to 1.5ml/80cm²/h, test mode to continuous spray, and test duration to 72 hours;
•  Sample placement: Fix the samples on the sample rack to ensure that the sample surface forms an angle of 15°-30° with the salt spray direction, and the sample spacing is ≥20mm to avoid mutual shielding;
•  Start the test: Start the salt fog test machine, which automatically completes temperature rise, atomization, spray and other processes, and real-time monitor the temperature and salt spray settlement rate during the test;
•  Result evaluation: After the test, take out the samples, rinse the surface salt deposits with clean water, observe the corrosion after drying, and evaluate the rust area and coating adhesion according to GB/T10125 standard.

4.2 Measured Data and Analysis
The test results of 3 galvanized steel sheet samples are shown in the following table:

Sample No.	Test Duration	Rust Area Ratio	Coating Peeling	Corrosion Resistance Grad
1#	72h	0.80%	None	Excellent
2#	72h	0.60%	None	Excellent
3#	72h	0.70%	None	Excellent

The test results show that the rust area ratio of all 3 samples is less than 1% without coating peeling, indicating that the corrosion resistance of this batch of galvanized steel sheets meets the industry standards. At the same time, during the test, the temperature fluctuation of the LISUN YWX/Q-010 salt fog test machine is always controlled within ±0.3℃, and the average salt spray settlement rate is 1.48ml/80cm²/h, with minimal deviation from the set value, verifying the test accuracy of the equipment.

5. Conclusion and Outlook
As a professional testing equipment complying with multiple international and domestic standards, the LISUN YWX/Q-010 salt fog test machine can efficiently complete salt spray corrosion testing tasks with its stable temperature control, precise salt spray settlement rate adjustment and multi-mode test function, providing reliable guarantee for quality control in various industries. The equipment is not only suitable for corrosion resistance testing of metal materials and coated products, but also widely used in electronic components, light industrial products, military equipment and other fields, with strong practicality and compatibility.

With the continuous improvement of industrial manufacturing’s requirements for product reliability, intelligence, large-scale and multi-functionality of salt fog test machines will become the development trend. In the future, the LISUN YWX/Q-010 salt fog test machine can further optimize the control system, add functions such as remote monitoring and automatic data analysis, and expand the scope of test environment simulation to better meet the testing needs in complex scenarios and inject stronger momentum into the high-quality development of industry.

Tags：YWX/Q-010