Wear resistant steel grades offer a harder and tougher alternative to conventional high-strength steel, and are suitable for high-performance applications. This article reviews what makes a steel wear resistant, the different grades and their characteristics, as well as a typical chart.
What is Abrasion Resistant Steel
Wear resistant steel is a category of steel with a design that allows it to withstand high levels of wear and also abrasion in various applications. This type of steel provides exceptional durability and longevity in environments where materials experience constant friction, impact, or sliding contact. Thus, it also goes by the name, abrasion resistant (AR) steel. The following sections highlight some predominant features of this type of steel.
High Hardness
Abrasion resistant steel offers exceptional hardness, with alloying elements such as carbon, manganese, and chromium playing a critical role. Measurement of hardness is often on the Brinell scale, with common grades such as AR400 and AR500 indicating a hardness of 400 and 500 Brinell, respectively.
Toughness and Strength
Despite its high hardness, abrasion resistant steel also maintains a degree of toughness and strength. Hence, allowing it to absorb impact without cracking or breaking.
Low Coefficient of Friction
Many wear resistant steel grades are formulated to have a low coefficient of friction. Therefore, reducing the amount of energy lost due to sliding motion and enhancing their resistance to wear.
Good Machinability
Some types of wear resistant steel can be machined effectively, allowing for easy fabrication into various shapes and components.
Corrosion Resistance
While not all wear resistant steels are inherently resistant to corrosion, many formulations include alloying elements that provide improved corrosion resistance, extending the material’s service life.
What Makes Steel Wear Resistant
There are several factors that influence the resistance of steel to wear. Moreover, the variation of these factors is what results in different grades of wear resistant steel. The following sections highlight some of these factors.
Chemical Composition
- High Carbon Content: The addition of carbon increases the hardness of steel. Generally, wear resistant steels have a carbon content above 0.5%, giving them the ability to endure high levels of wear from abrasive materials. Higher carbon levels can lead to a hardening effect, making the steel less susceptible to wear, so there must be a balance.
- Chromium: Improves hardness and adds corrosion resistance. Chromium also forms hard carbides in the steel matrix, which enhance wear resistance.
- Manganese: Increases toughness and hardenability, providing additional resistance to wear and impacts.
- Molybdenum: Helps in improving hardness at elevated temperatures and enhances toughness.
- Vanadium and Tungsten: These elements enhance hardenability and strength, contributing to better wear resistance through the formation of complex carbides.
Microstructure
- Martensitic Structure: Wear resistant steels often exhibit a martensitic microstructure, which results from rapid cooling (quenching) of the steel from its austenitizing temperature. Martensite is a very hard and brittle phase that significantly increases the hardness of steel. Thus, making it less prone to wear.
- Carbide Distribution: The presence and distribution of carbides (such as titanium carbides or chromium carbides) within the steel matrix play a crucial role in wear resistance. Having well-distributed, hard carbides can significantly enhance the material’s ability to withstand abrasion.
- Austenitic and Ferritic Phases: Some wear resistant steels incorporate a mix of austenitic and ferritic phases. Having these two phases can provide a balance between hardness and toughness. This can be particularly useful in applications where impact resistance is also vital.
Heat Treatment Processes
The combination of heating steel to a high temperature (quenching) and then reheating it to a lower temperature (tempering) develops a balance of hardness and toughness. This process is crucial for enhancing wear resistance while reducing brittleness. Creating some wear resistant steels entails cryogenic treatment, where they are cooled to very low temperatures. This can help convert retained austenite into martensite and refine the microstructure, further improving wear resistance.
Surface Treatment
Surface hardening techniques like carburizing, nitriding, or induction hardening increase the hardness of the steel’s surface while maintaining a tougher core. This allows for better wear resistance while enduring impact without cracking. Another surface treatment option is applying hard coatings like titanium nitride or chromium nitride. Such coatings provide an additional barrier to wear and can add corrosion resistance.
Abrasion Resistant Steel Grades
There are a variety of wear resistant steel grades in the industry, including bespoke options on offer from manufacturers. So, the following sections highlight some common options, and is not an exhaustive list.
AR 200
AR200 typically has a hardness range between 170 and 250 BHN (Brinell Hardness Number). It offers moderate wear resistance and is suitable for general-purpose applications where some degree of resistance to wear is necessary. This medium-carbon manganese steel is often employed in applications such as truck liners, material chutes, and bulk handling equipment.
AR 235
The AR 235 or Manganese Steelis known for its high toughness and resistance to wear and tear. They usually contain 12-14% manganese and 0.8-1.25% carbon with a moderate abrasion resistance, but excellent resistance to impact. These steels have good weldability and formability properties making them versatile in various application. As a result, they are commonly used as crusher hammers, mining equipment, chutes and railroad track work.
AR 400
AR400 stands out due to its high abrasion resistance, typically ranging from 360 to 444 BHN. This grade is well-known for its good weldability and toughness, hence, making it a common choice in construction and mining equipment including bucket liners, wear plates, and hoppers. AR400 is ideal for applications where durability is crucial, effectively enhancing the performance of heavy machinery and material handling systems.
AR 450
For even greater demands, AR450 offers exceptional hardness, with a range from 420 to 470 BHN. This grade exhibits more surface hardness than AR400 while maintaining good ductility and formability. AR450 steel typically serves in applications involving moderate to severe wear, such as dump truck bodies, heavy equipment parts, and mining operations.
AR 500
AR500 provides excellent hardness, with a range from 477 to 534 BHN. This grade demonstrates very high abrasion and impact resistance. Hence, making it perfect for high-wear applications such as mining tools, construction machinery components, and military applications. The increased hardness of AR500 steel typically leads to lower machinability but superior performance in environments exposed to severe wear.
AR 600
For extreme wear resistance, AR600 reaches hardness levels from 570 to 625 BHN. This grade provides superior abrasion protection in applications such as armor plating for military vehicles, excavation buckets, and cutting edges. While its high hardness confers outstanding wear resistance, it also results in reduced formability, limiting its use in applications that require significant bending or shaping.
Wear Resistant Steel Chart
Wear resistant steel chart serves as a quick guide for industry professionals during the material selection process. A typical chart shows various steel grades and their features such as hardness, yield strength, and application, like in the table below.
| Grade | Hardness Range (BHN) | Yield Strength (MPa) | Typical Applications |
| AR200 | 170 – 250 | ~350 | General-purpose applications, light machinery components |
| AR235 | 200 – 260 | ~400 | Agricultural equipment, moderate wear applications |
| AR400 | 360 – 444 | ~1,000 | Heavy machinery, mining equipment, structural beams |
| AR450 | 420 – 470 | ~1,250 | Dump truck bodies, construction equipment parts |
| AR500 | 477 – 534 | ~1,450 | Mining tools, high-wear machinery components |
| AR600 | 570 – 625 | ~1,700 | Extreme wear applications, specialized tooling |
Wear Resistant Steel Grades from Ferro-Tic
At Ferro-Tic, we offer different grades of steel-bonded carbide components, suitable for your severe wear applications. Generally, our formulations include extremely hard titanium carbide grains that are uniformly distributed through a hardenable metal matrix. As a result, our steel grades are wear resistant, while still being readily machinable using conventional techniques. Contact us today, as we partner in delivering the best components for your application.