According to statistics, the direct economic loss caused by metal corrosion accounts for 2%~4% of GDP every year.
It is also reported that about 1/3 of the metals smelted in the world are scrapped in the industry due to rust.
In order to avoid rusting, people use a variety of methods, using rust inhibitor to protect metal products is one of the most common protection methods.
Iron rust is red, copper rust is green, and aluminum and zinc rust become white rust.
From the industrial point of view, the corrosion of iron and steel should be paid the most attention.
Antirust oil is an oil with antirust function, which is composed of oil soluble corrosion inhibitor, base oil and auxiliary additives.
Antirust oil is widely used for antirust of mechanical products, sealing antirust of various metal products and antirust of processes.
According to different properties and uses, antirust oil can be divided into the following categories:
1. Replacement anti rust oil
Generally, the displacement type antirust oil uses sulfonate with strong adsorption as the main antirust agent, which can replace the water and sweat on the metal surface to prevent corrosion caused by human sweat.
At the same time, the displacement type antirust oil itself absorbs on the metal surface and generates a firm protective film to prevent the invasion of foreign corrosion media.
Therefore, it is widely used for rust prevention between processes and surface pretreatment before long-term rust prevention.
There are also many replacement antirust oils that can be directly used for sealing and antirust.
According to the domestic standard SH0367-92 for replacement rust preventive oil, such oil products are divided into No. 1, No. 2, No. 3 and No. 4.
2. Solvent diluted antirust oil
These antirust oils contain volatile petroleum solvents or are diluted with solvents when used at room temperature.
It includes solvent-diluted hard film antirust oil, solvent-diluted soft film antirust oil, solvent-diluted replaceable antirust oil, etc.
After this kind of antirust oil is coated on the metal surface, the solvent will volatilize naturally and form a uniform protective film.
It is generally used for rust prevention on the surface of large mechanical equipment, and some can even be used for the sealing of raw materials and equipment stored in the open air.
The disadvantage is that it is allowed to contact and package each other only after the solvent volatilizes, otherwise it will stick together.
Therefore, it is only applicable to workpieces with simple structure.
It is not applicable to workpieces with complicated structures and small holes produced in large quantities, and it is not suitable for internal sealing.
The petrochemical industry standard of solvent-diluted antirust oil is SH0366-92, and the national standard is GB4879-85B2, which is divided into:
No. 1 – hard film, suitable for indoor and outdoor long-term storage;
No. 2 – Soft film, suitable for indoor long-term storage;
No. 3 – Water displacement type soft film, which can replace water, and is suitable for rust prevention of indoor metal products;
No. 4 – Transparent and non sticky film.
3. Seal antirust oil
Sealed antirust oil has the characteristics of normal temperature coating, no solvent, thin oil film, antirust between processes and long-term storage, good compatibility with lubricating oil, no need to clean when unsealing, etc.
Generally, it can be divided into soaking type and coating type.
(1) Immersion type
The products can be completely immersed in a plastic bottle filled with antirust oil for sealing.
It is OK to add 2% or less corrosion inhibitor in the oil, but it is necessary to add antioxidant frequently to prevent the oil from oxidative deterioration.
(2) Coated type
Thin layer oil varieties that can be directly used for coating.
More corrosion inhibitors need to be added to the oil, and several corrosion inhibitors need to be used together.
Sometimes, tackifiers, such as polyisobutylene, need to be added to improve the viscosity of the oil film.
It can be used for long-term indoor storage with good rust prevention effect if matched with the external packaging.
The national standard for sealing antirust oil is GB4879-85 B3.
4. Emulsified antirust oil
This is a kind of oil containing rust inhibitor and emulsifier.
When used, it is diluted with water to become emulsion, so it is called emulsified antirust oil.
It has the characteristics of low cost, safe use, reducing environmental pollution, saving energy and so on.
It is coated on the metal surface and forms a protective oil film after the water evaporates.
At present, it is mainly used for rust prevention between processes, and can also be used for long-term storage.
The domestic standard of emulsified antirust oil is GB4879-85 B4.
5. Antirust lubricating oil
This is a so-called dual-use oil with dual properties of lubrication and rust prevention.
It is required that after unsealing, it can be directly installed and used without removing the sealing oil.
Or after the test run, it is not necessary to change the oil, that is, the test run oil is used to seal the product, which is generally used for systems requiring lubrication or sealing.
According to the use, it can also be divided into internal combustion engine rust proof oil, hydraulic rust proof oil, main shaft oil, gear oil, air compressor oil, instrument and bearing rust proof oil, rust proof test oil, etc.
6. Anti rust grease
It is a paste made by adding antirust additives to the base oil of industrial vaseline or petroleum wax such as paraffin wax and paraffin wax.
Generally, the hot coating method is used for sealing.
It is characterized by oil film thickness (generally about 0.01-0.2mm, or even 0.2-1mm), high oil film strength, resistance to loss and volatilization, and rust prevention period of more than 2 years.
It is widely used for long-term storage of mechanical products and large equipment.
The disadvantage is that the oil seal and unsealing need to be heated, which requires good thermal stability and oxidation resistance stability.