Water cooling systems are widely used in industrial production, refrigeration and air conditioning fields due to their efficient heat transfer performance. However, corrosive media such as oxygen, salt, and microorganisms in circulating water can cause continuous erosion of metal components in the system, leading to serious problems such as pipeline leaks and equipment scrapping.Corrosion inhibitor for water cooling systemBy forming a protective barrier on the surface of metals through physical or chemical actions, it provides precise protection against the corrosion characteristics of common materials such as carbon steel, copper, and aluminum, and is the core agent for ensuring the long-term operation of the system. It is crucial to clarify its protected object and mechanism of action for the maintenance of the water cooling system.

Carbon steel is a widely used basic material in water cooling systems, such as pipes and radiator shells, which are often made of carbon steel and therefore become a key protected object for corrosion inhibitors. Carbon steel is prone to oxygen corrosion in an oxygen rich water environment, forming loose rust (Fe ₂ O ∝· nH ₂ O). This rust product cannot prevent the corrosion from continuing to deepen, ultimately leading to thinning and perforation of the pipeline wall. The corrosion inhibitors for carbon steel are mainly passive and adsorption types: chromate corrosion inhibitors can form a dense oxide film on the surface of carbon steel, blocking the contact between the corrosive medium and the metal substrate; Organic amine corrosion inhibitors adsorb molecules onto metal surfaces, forming a hydrophobic protective film that inhibits the erosion of oxygen and water molecules. In systems with low pH values in circulating water, it is necessary to use amine corrosion inhibitors to adjust the acidity and alkalinity, further reducing the risk of hydrogen depolarization corrosion of carbon steel.

Copper and copper alloys (such as brass and copper) are commonly used in key components such as heat exchange tubes and valves in water-cooled systems, and their corrosion forms are mainly zinc removal corrosion and pitting corrosion. Copper is prone to react with carbon dioxide and chloride ions in water to generate soluble copper ions, while brass components are prone to "de zincing" due to the preferential dissolution of zinc elements, leading to material brittleness and cracking. Corrosion inhibitors for copper materials have high specificity, and benzotriazole (BTA) and its derivatives are typical representatives. They can form stable chelates with copper ions, construct a strong protective film on the copper surface, and prevent copper dissolution and migration. In addition, mercaptobenzothiazole (MBT) corrosion inhibitor performs better in high flow rate water environments and can effectively inhibit the erosion corrosion of copper alloys, making it particularly suitable for dynamic water circulation systems such as central air conditioning.

Aluminum and aluminum alloys are widely used as heat dissipation components for small water cooling equipment due to their light weight and good thermal conductivity. However, aluminum is chemically active and prone to corrosion. In neutral or weakly alkaline water, the oxide film on the surface of aluminum is easily damaged, forming white corrosion products of aluminum hydroxide, which leads to a decrease in heat dissipation efficiency. Corrosion inhibitors for aluminum materials are mostly organic phosphonates and silicates. The former can form complexes with aluminum ions to inhibit the dissolution of oxide films; The latter enhances the stability of the oxide film by forming a silane protective film on the surface of aluminum. It should be noted that aluminum is extremely sensitive to chloride ions, so corrosion inhibitors used for aluminum components also need to have a certain degree of scale inhibition ability to avoid the formation of scale layers by the combination of chloride and calcium magnesium ions, which can exacerbate local corrosion.

In practical applications, water cooling systems often have multiple metal materials coexisting, which requires corrosion inhibitors to have "broad-spectrum protection" capabilities while avoiding galvanic corrosion between different metals. For example, when carbon steel comes into contact with copper components, copper acts as a cathode to accelerate the corrosion of carbon steel. In this case, a composite corrosion inhibitor should be selected to form an adsorption film on the surface of carbon steel and protect copper components from corrosion. In addition, the selection of corrosion inhibitors also needs to be combined with water quality conditions. For example, anti scaling and corrosion inhibitors should be used in high hardness water, and the concentration of corrosion inhibitors should be increased in high salt water to ensure effective protection in harsh environments.

The corrosion problem of metal materials such as carbon steel, copper, and aluminum, from industrial boilers to household water purifiers, has always been a "serious concern" for water cooling systems. Corrosion inhibitors build personalized protection systems by accurately matching the corrosion characteristics of different metals, providing a "safety umbrella" for metal components in the system. With the upgrading of environmental protection concepts, new types of phosphorus free and low toxicity corrosion inhibitors continue to emerge, which not only achieve efficient protection but also reduce their impact on the environment, providing strong guarantees for the green operation and maintenance of water cooling systems.