Good Article Corrosion Principle of Photovoltaic Support

 THE FATE OF STEEL

  Steel is the most widely used metal material in industrial architecture,because it has relatively stable mechanical property, good plasticity, and high strength.However, steel materials are easily corroded in nature. Rust can affect the appearance, and even damage the quality of the structure, and eventually lead to the collapse of the building and cause an accident.

TYPES OF CORROSION

  We mainly consider the influence of corrosion on the design of photovoltaic support from the following three aspects:

• Atmospheric Corrosion: The upper support structure exposed to the atmosphere will interact with oxygen and water in the air to produce corrosion. This corrosion is the most common and the easiest to detect.

  
  

  

• Soil Corrosion: Under the action of various substances in the soil, the buried steel pile foundation will have more complex chemical reactions, which will lead to corrosion. In fact, such corrosion is difficult to detect due to long-term exposure to soil.

  
  

  
  

  

• Contact Corrosion: Due to the difference of electric potential between different metals, the gain and loss of electrons will occur, thus forming electrochemical corrosion, which is often ignored by designers.

  METHODS TO PREVENT CORROSION

  

  The common way to alleviate or avoid steel corrosion in the industry is to galvanize the steel surface.

  Due to galvanic effect formed by zinc and iron, the corrosion resistance of zinc coating will not be affected even if slight damage occurs during transportation or installation. Of course, extra care should be taken for deeper damage, which requires zinc supplementation. In addition, zinc reacts with air and water to produce a new product: basic zinc carbonate. This material has a compact surface and is not easy to dissolve in water, which can isolate air from iron, thus forming a layer of "physical protection" and further slowing down the corrosion of steel.

  Common galvanizing processes are: hot dip galvanizing, pre galvanizing and electro galvanizing (cold galvanizing).