In the field of corrosion resistance testing for industrial products,Programmable salt spray testing machineAs a key equipment, it provides scientific basis for improving product quality by simulating the erosion effect of high salt environments such as the ocean on materials. The scientific design and working principle of its structure directly determine the accuracy and reliability of the experimental results. The following analysis will be conducted from two aspects: structural characteristics and working principles.

1、 Structural features: Precise design ensures test stability

Programmable salt spray testing machineIts core structure consists of a box, a spray system, a temperature and humidity control system and auxiliary devices. Each module works together to achieve environmental simulation.

1. Box Structure
The box is made of high-strength and corrosion-resistant materials (such as imported ones)PVCReinforced rigid plastic board or epoxy glass fiber reinforced plastic) is molded as a whole, with smooth surface and aging resistance. The interior adopts a water sealed structure, and a sealing groove is used between the box cover and the box body to prevent salt spray leakage, ensuring the sealing of the test environment. There is a sample bracket inside the box, which is made of non-metallic materials such as glass and plastic to avoid interference with the test results caused by the reaction between the metal bracket and salt spray. The suspension angle of the sample strictly follows the standard requirements (perpendicular to the vertical direction)15°~30°Angle) to maximize the simulation of corrosion in actual usage scenarios.

2. spray system
The spray system is of the testing machine“heart”It is composed of a tower spray, a glass sprayer, a conical disperser and a pressure regulating device. Compressed air carrying salt solution is atomized through a nozzle to form micrometer sized salt spray particles, which are uniformly dispersed throughout the entire laboratory through a conical disperser. The spray volume can be continuously or periodically controlled by adjusting the height of the conical diffuser to meet the requirements of different test standards. The nozzle is made of special glass or quartz material, which is resistant to crystallization and blockage, ensuring long-term stable operation.

3. Temperature and humidity control system
The system simulates the environment by heating the water tank and saturating the air tank. The heating water tank is attached to the bottom of the laboratory to maintain a constant temperature inside the chamber; The saturated air tank is made of stainless steel material, and the compressed air is heated and humidified according to Henry's law to provide the required humidity for the experiment. Temperature sensors (such as platinum resistors)PT100Ω）With high precisionPIDController linkage to achieve temperature fluctuations≤±0.5℃Accurate control.

4. auxiliary device
Including salt collection system (funnel cup)+Measuring cylinder, water quality filter, automatic water replenishment device, and safety protection module. Real time monitoring of salt spray settlement by salt liquid collection system; Water quality filters prevent nozzle blockage; Automatic water replenishment device ensures the risk of test interruption; The security protection module covers functions such as over temperature alarm and low water level power-off, ensuring the safety of equipment and personnel.

2、 Working principle: Electrochemical corrosion acceleration simulation

Programmable salt spray testing machineBy artificially accelerating the corrosion process, the failure mechanism of materials in salt spray environment is revealed, based on the dual effects of electrochemical corrosion and chloride ion erosion.

1. Electrochemical corrosion process
After the salt solution is atomized, a thin layer of electrolyte film is formed on the surface of the metal sample, which forms the primary battery with the metal substrate. Oxidation reaction occurs in the anode region (metal)（Fe → Fe²⁺ + 2e⁻）Reduction reaction occurs in the cathode region (corrosion products)（O₂ + 2H₂ O + 4e ⁻ → 4OH⁻）Causing the metal to gradually dissolve. Different metal combinations or coating defects can accelerate local corrosion, forming pitting or crevice corrosion.

2. Chloride ion erosion
In the salt mistCl⁻It has strong penetrability and can destroy the oxide film on the metal surface, directly reacting with the metal to generate soluble chlorides (such asFeCl2）. Meanwhile,Cl⁻The migration in the corrosion product layer will intensify crack propagation and significantly shorten the corrosion cycle. For example, neutral salt spray test（NSS）The carbon steel sample is in the middle48Significant rusting can occur within hours, while it takes several years for the natural environment to reach the same level.

3. Experimental process control
The testing machine atomizes the salt solution through compressed air, and the salt spray particles uniformly cover the surface of the sample. The user can set the test parameters (temperature, humidity, spray cycle) through the touch screen, and the equipment automatically executes continuous or intermittent spray. During the experiment, the system monitors and records environmental data in real-time. After the experiment is completed, the corrosion resistance of the material is evaluated based on the amount of salt solution collected and the corrosion morphology of the sample.

3、 Application value: Quality protection from laboratory to industry

Programmable salt spray testing machineWidely used in fields such as automotive, electronics, aerospace, etc., it provides key data for material selection, coating process optimization, and product life prediction. For example, automotive parts are processed throughCASSThe experiment (acid salt spray) can quickly verify the corrosion resistance of the coating and shorten the research and development cycle60%The above. The scientific nature of its structure and principles makes it a quality control tool“Corrosion resistant microscope”Promote the upgrading of industries towards high reliability.