There are a variety of ways to prevent the corrosion of iron, please state the principle of the following various anti-corrosion methods: 1. in the surface of iron plated with a layer of metal aluminu

There are a variety of ways to prevent the corrosion of iron, please state the principle of the following various anti-corrosion methods: 1. in the surface of iron plated with a layer of metal aluminum 2. in the ship's 1, in the metal surface covered with a variety of protective layer, the protected metal and corrosive media isolation, is an effective way to prevent metal corrosion. Industry commonly used protective layer of non-metallic protective layer and metal protective layer of two categories. They are chemical methods, physical methods and electrochemical methods to achieve. 1 and 3 belong to this category;

2, electrochemical protection method

Electrochemical protection method is based on the principle of electrochemistry in the metal equipment to take measures, so that it becomes the cathode in the corrosive battery, so as to prevent or mitigate the corrosion of the metal method.

①Sacrificial anode protection method

Sacrificial anode protection method is to use the electrode potential lower than the protected metal metal or alloy as the anode, fixed in the protected metal, the formation of corrosion battery, the protected metal as the cathode and get protection.

Sacrificial anode generally commonly used materials are aluminum, zinc and its alloys. This method is commonly used to protect the shell of the ocean liner, seawater in a variety of metal equipment, components and to prevent corrosion of giant equipment (such as oil storage tanks) and petroleum pipelines.

②Applied current method

The protected metal and another additional electrode as the two poles of the electrolytic cell, so that the protected metal as the cathode, the cathode is protected under the action of the applied direct current. This method is mainly used to prevent corrosion of metal equipment in soil, seawater and river water.

3 belongs to this category.