Abrasive wear – definition, prevention

What is Abrasive Wear?

Abrasive wear is the loss of material by a rubbing or abrasive impact. It is usually caused by foreign particles caught between the running elements. This distinguishes it from adhesion, in case of which cold welding occurs without impact on foreign bodies. In addition to foreign bodies, asperities on the running partners themselves can also be responsible for abrasion. Abrasive damages can be prevented by suitable filter techniques, for instance. In many applications, however, this is only possible to a limited extent or impossible altogether. Due to product design, foreign materials are partially quite difficult to avoid, e.g., combustion residues in engines. If foreign materials cannot be completely excluded, increasing abrasion resistance of the running elements is a suitable method that is used to reduce wear. Abrasive damage is a problem in many areas of applications. It is the cause of gear damage, damage to pump components and pipes, engine parts and joint components.

Key Industries and Applications Affected by Abrasive Wear

Industries or applications prone to abrasive wear often involve heavy machinery, harsh environments, or the frequent movement of materials, leading to the inevitable erosion of components. Abrasive wear can significantly impact the efficiency, safety, and lifespan of equipment in these sectors. Key industries and applications include:

• Mining and Quarrying: Equipment used in excavation, drilling, and ore processing faces constant abrasion from rock, minerals, and sand.
• Agriculture: Machinery such as tractors and harvesters are exposed to soil, debris, and plant material, leading to abrasive wear on moving parts.
• Construction: Tools and equipment, including excavators, loaders, and bulldozers, encounter abrasive materials like concrete, gravel, and dirt.
• Manufacturing and Processing: Components in conveyor systems, crushers, and grinding mills are subject to wear from processed materials.
• Oil and Gas: Pipelines and drilling equipment deal with abrasive particles present in crude oil and natural gas, leading to wear on internal surfaces.
• Energy Production: In power plants, especially those using coal, the transportation and processing of fuel can cause significant abrasive wear on machinery.

Different Types of Abrasive Wear

Abrasive wear manifests in several distinct types, each characterized by the conditions under which the material loss occurs. These types include:

• Two-body abrasive wear: Two-body abrasion occurs when hard particles or asperities are embedded in one surface, directly abrading the opposing surface with which it comes into contact. It’s akin to the action of sandpaper on wood, where the abrasive particles are fixed and directly wear down the material surface.
• Three-body abrasive wear: Involves loose abrasive particles that exist between two contacting surfaces, leading to wear on one or both surfaces. Three-body abrasion is common in mechanisms where debris or external abrasive particles can enter the system, acting as a layer of moving particles that grinds down the material surfaces.
• Gouging abrasion: Characterized by the removal of large material chunks due to heavy and rough contact, often seen in mining and earth-moving equipment where large, hard particles impact equipment surfaces.
• High-stress abrasion: Occurs under conditions where abrasive particles exert significant force against a material, leading to deep grooves and high material removal rates. This type is common in industrial processes involving grinding and milling.
• Low-stress abrasion: Features abrasive particles sliding against a surface with minimal force, leading to wear primarily through micro-cutting and micro-plowing, without significant material removal. This type is typical in applications where surfaces slide against each other with abrasive particles trapped in between, such as in bearings or between moving mechanical parts.

Increasing Abrasion Resistance

To increase abrasive wear resistance, attempts are also made to increase the hardness and strength of the rubbing partners. This is then called increased abrasion resistance. To this end, the hardening of stainless steel can be a solution. In many applications, such as pipelines in the food industry, it is thus also necessary for stainless steel to be resistant to corrosion to meet high demands. Conventional methods cannot achieve this. It is true that they increase abrasion resistance, but only by simultaneously becoming less resistant to corrosion. This is where the BORINOX® PROCESS FOR STAINLESS STEEL HARDENING is applied. It produces a surface which is up to 5 times harder, with a significant increase in abrasion resistance to foreign bodies. Nevertheless, the processed steel retains properties urgently required in many applications, such as corrosion resistance. BORINOX® is thus particularly suitable for hardening stainless steel or rustproof steel.

Another way to protect your materials from wear, specifically targeting the challenge of abrasion, is through our BOROCOAT® diffusion process. This advanced treatment is specially designed to enhance the abrasion resistance of various materials by embedding boron into their surface.

In addition to BOROCOAT®, we offer other specialized services aimed at preventing abrasion and enhancing the wear resistance of materials, including:

• NICKELCOAT®: While primarily recognized for its corrosion resistance, the NICKELCOAT® electroless nickel plating process also significantly improves the wear resistance of treated surfaces. The uniformly deposited coating offers not only excellent protection against corrosive environments but also reduces wear in applications where components are subject to abrasive particles or sliding wear.
• Nitriding and Nitrocarburizing: These surface hardening processes are effective methods for increasing the abrasion resistance of steel and iron parts. By introducing nitrogen into the surface layer of the material, both nitriding and nitrocarburizing create a hard case that is resistant to wear. This is particularly beneficial for components that operate under high-friction conditions or are exposed to abrasive materials.

Each of these BorTec services leverages unique technologies and processes to counteract wear, with a particular focus on preventing abrasion. By applying treatments like BOROCOAT®, NICKELCOAT®, or nitriding processes, components are rendered more durable and capable of withstanding the demands of their operating environments. This focus on combating abrasion is critical for industries where material longevity and performance are directly linked to operational efficiency and cost-effectiveness.