As an important coating material in industrial rollers, tungsten carbide coating is widely used in many industrial fields, such as printing, steel, textile, papermaking and plastic processing, due to its excellent wear resistance, corrosion resistance and high hardness. Tungsten carbide coating can significantly improve the service life and performance of industrial rollers. However, the quality of coatings on the market varies greatly, so it is particularly important to distinguish whether industrial rollers use real tungsten carbide coatings.

This article will introduce in detail the basic characteristics of tungsten carbide coatings, how to identify its authenticity through scientific testing methods, and how to avoid counterfeit tungsten carbide coating products when purchasing industrial rollers.

What are the characteristics of tungsten carbide coatings?

Tungsten carbide is a chemical substance composed of tungsten and carbon elements, with extremely high hardness and strength. Its Mohs hardness is close to 9, second only to diamond, so it has excellent wear resistance. At the same time, tungsten carbide also has good corrosion resistance and high temperature resistance, and can maintain high physical properties in extreme environments.

High Hardness

The hardness of tungsten carbide makes it very suitable as a protective coating for the surface of industrial rollers. Compared with other coating materials, tungsten carbide can withstand most friction and impact, significantly extending the service life of the roller. By applying tungsten carbide coating, industrial rollers can maintain stable performance under high-intensity operations.

Wear resistance

The wear resistance of tungsten carbide coating is one of its most significant characteristics. In industrial applications, the surface of the roller is often subjected to continuous friction. Without sufficient wear resistance, the roller will quickly lose its function. Tungsten carbide coating can effectively slow down the wear rate, so that the roller can still work normally under high load.

Corrosion resistance

In industrial environments, rollers are often exposed to corrosive media (such as acid, alkali, and salt solutions). If there is no sufficient corrosion-resistant protective layer on the surface of the roller, the coating is easily corroded. Tungsten carbide coating can effectively resist the invasion of these corrosive media and extend the service life of the roller.

High temperature resistance

The melting point of tungsten carbide coating is as high as 2870°C, which can maintain its physical properties unchanged in high temperature environments, so it is suitable for high temperature operation occasions, such as metallurgy, steel rolling and other industries.

How to identify the authenticity of tungsten carbide coating?

To identify whether the tungsten carbide coating of industrial rollers is authentic, you can make a preliminary judgment based on the appearance characteristics, or you can make in-depth inspections with the help of scientific instruments and testing methods. The following are some common methods to identify the authenticity of tungsten carbide coatings:

Preliminary judgment based on appearance and touch

Appearance inspection:

Tungsten carbide coatings usually appear dark gray or metallic luster, with a delicate texture. The surface of the real tungsten carbide coating is uniform, without obvious scratches or depressions. However, inferior counterfeit tungsten carbide coatings often have a rough and uneven surface, and even powdering. If you observe or touch the surface of the coating with the naked eye and find that it does not have the smooth and hard texture it should have, it may not be a tungsten carbide coating.

Tactile inspection:

Due to its hardness and high density, tungsten carbide coatings give people a more solid and smooth feeling when touched, rather than a rough or loose touch. If you feel loose particles or uneven texture on the surface during touch, it is likely to be a counterfeit product.

Hardness test

One of the most direct ways to identify tungsten carbide coatings is to conduct a hardness test. Tungsten carbide has extremely high hardness, usually reaching 70HRC (Rockwell hardness) or more. Therefore, the hardness of the coating can be tested by using tools such as Rockwell hardness tester. If the test result is lower than the hardness value of standard tungsten carbide, then the coating may not be real tungsten carbide.

Hardness test steps:

● Use a hardness tester to test multiple points on the surface of the industrial roller.

● Test the hardness values at different locations to determine whether they meet the hardness standards of tungsten carbide.

It should be noted that the accuracy of the hardness test depends on the accuracy of the test equipment and the professionalism of the operator, so this test usually needs to be completed by experienced technicians.

X-ray fluorescence spectroscopy (XRF analysis)

X-ray fluorescence spectroscopy is one of the effective methods to identify tungsten carbide coatings. This technology can quickly analyze the elemental composition in the coating to determine whether it contains tungsten carbide. Through XRF analysis, the chemical composition ratio of the coating can be detected to confirm whether it contains a sufficient proportion of carbon and tungsten, thereby verifying the authenticity of the coating.

XRF analysis steps:

● Aim the XRF instrument at the surface of the coating for scanning.

● Obtain the content of each element in the coating, especially the content of tungsten and carbon.

● Determine whether the coating is tungsten carbide based on the test results.

XRF analysis is a non-destructive testing method that does not damage the coating surface, so it is widely used in industrial testing.

Microstructure analysis

Analyzing the microstructure of tungsten carbide coatings using scanning electron microscopy (SEM) or transmission electron microscopy (TEM) is also an effective way to identify tungsten carbide coatings. Genuine tungsten carbide coatings have uniform microstructure and particle distribution, while counterfeit coatings usually have impurities or irregular particle arrangement.

Microstructure analysis steps:

● Take samples and place them under an electron microscope for observation.

● Analyze the morphology, distribution and size of the coating particles.

● Compare the structural characteristics of standard tungsten carbide coatings to determine whether the coating meets the standards.

Through microstructure analysis, you can gain an in-depth understanding of the quality and authenticity of the coating and avoid using inferior or counterfeit tungsten carbide coatings.

Wear resistance test

Tungsten carbide coating is known for its excellent wear resistance, so the authenticity of the coating can be judged by wear resistance test. Usually, the wear resistance test detects the wear of the coating by applying a certain friction force on the surface of the coating. The genuine tungsten carbide coating wears very little under high-intensity friction, while the counterfeit coating is prone to large-scale wear or peeling.

Wear resistance test steps:

● Apply a certain friction load on the coating surface and conduct a friction test for a period of time.

● Observe the wear of the coating surface to determine whether it meets the wear resistance standard of tungsten carbide.

Wear resistance tests usually need to be carried out under laboratory conditions to ensure the accuracy of the test results.

Corrosion resistance test

Another notable feature of tungsten carbide coating is its excellent corrosion resistance. Therefore, its authenticity can also be identified through corrosion resistance testing. Common testing methods include exposing the coating to a corrosive environment (such as acid and alkali solution) for a period of time and observing the surface changes of the coating. The genuine tungsten carbide coating should be able to maintain a good condition in the corrosive medium, while the counterfeit coating is prone to corrosion, shedding, etc.

Corrosion resistance test steps:

● Immerse the roller coating part in the acid and alkali solution.

● Take it out after a period of time and observe the changes in the coating surface.

● Compare the results to determine whether the coating has the corrosion resistance of tungsten carbide.

How to avoid purchasing fake tungsten carbide coated industrial rollers?

When purchasing industrial rollers, companies can take the following measures to avoid purchasing fake tungsten carbide coated products:

1. Choose a reputable supplier: Choose a supplier with a good reputation and long-term operating experience to ensure that the purchased products are certified and tested.

2. Request a test report: When purchasing tungsten carbide coated industrial rollers, require the supplier to provide relevant test reports to ensure that the composition, hardness and performance of the coating meet the standards.

3. Conduct a field investigation: If conditions permit, conduct a field investigation to understand the supplier's production process and quality control measures to ensure reliable product quality.

4. Regular maintenance and testing: Regularly maintain the industrial rollers after purchase, and use scientific means to test the quality of the coating to detect potential problems in a timely manner.

In summary: It is crucial to identify whether the tungsten carbide coating of industrial rolls is authentic. Scientific methods such as hardness testing, XRF analysis, microstructure analysis, and wear and corrosion resistance testing can effectively identify the authenticity of the coating. When purchasing industrial rolls, choosing a trusted supplier and requesting relevant test reports are important measures to ensure the authenticity of the tungsten carbide coating.

JH Machinery stands out as a professional roll manufacturer in China, offering over 20 years of experience in industrial roll design and production. Our ISO9001-certified facility specializes in producing precision-engineered rolls, such as polyurethane rolls, mirror rolls, and tungsten carbide rolls. We cater to a broad range of industries, including metallurgy, automotive testing, and packaging. With wholesale pricing, tailored solutions, and exceptional after-sales support, we provide reliable products to meet your business needs.