Boron in Steel – Definition and Applications

The Difference between Boron Steel and Boronized Steel

Boron steel is created by integrating boron throughout the entire steel matrix, typically in concentrations ranging from 0.0003% to 0.003% by weight. This incorporation results in significantly enhanced hardenability and tensile strength, making boron steel ideal for demanding applications such as automotive crash structures and agricultural machinery. However, due to the through-hardening nature of boron steel, it tends to be less ductile and more brittle than steels without boron.

On the other hand, boronized steel involves a surface treatment where boron is diffused into the outer layer of the steel, leaving the core material unaffected. This process, achieved through our proprietary BOROCOAT® method, enhances surface hardness while maintaining the material’s core ductility. Boronized steel is especially suited for applications requiring high wear resistance, such as oil and gas components, valve seats, and pump impellers.

Industrial Applications: Boron Steel vs. Boronized Steel

Boron Steel: Boron steel, with its enhanced hardenability, is extensively used in applications requiring high strength and durability.

• Automotive Industry: Boron steel is widely employed in the automotive sector for the manufacturing of high-strength structural components such as crash beams, chassis parts, and roll cages. These components benefit from boron steel’s ability to maintain consistent strength throughout, making them ideal for safety-critical applications where impact resistance is crucial.
• Construction and Agricultural Equipment: Boron steel is also favored in the construction and agricultural industries. It is used to produce high-strength reinforcing bars (rebar) and durable agricultural tools such as plowshares and harrows. These applications benefit from boron steel’s through-hardening properties, which ensure that both surface and core remain robust under heavy use.

Boronized steel, treated through the BOROCOAT® process, is highly valued in industries that demand exceptional surface hardness, wear resistance, and corrosion protection. This process diffuses boron into the steel surface, forming a hard, wear-resistant boride layer that is firmly bonded to the substrate. The versatility and durability of boronized steel make it suitable for a wide range of industrial applications:

• Oil and Gas Industry: In this sector, components such as valve seats, burner nozzles, and pump impellers are frequently exposed to abrasive environments and corrosive substances. Boronized steel’s enhanced surface hardness and corrosion resistance significantly increase the lifespan of these components, reducing downtime and maintenance costs​.
• Power Generation: Components used in power plants, such as turbine blades and heat exchangers, benefit from boronized steel’s ability to withstand high temperatures and resist wear. The boronized layer provides protection against both thermal and mechanical stress, ensuring the reliability and efficiency of these critical components​.
• Mechanical Engineering and Tooling: Boronized steel is ideal for high-precision tools, dies, and molds used in mechanical engineering. The process improves the wear resistance of these tools, which are subject to intense friction and stress during operation. This application is crucial for extending tool life and maintaining the precision of manufactured parts​​.
• Automotive Industry: While boron steel is typically used for structural components, boronized steel is applied to parts requiring enhanced surface properties, such as gears and camshafts. The boronized layer provides superior wear resistance, reducing the need for frequent replacements and ensuring the longevity of critical automotive components​.
• Manufacturing of Machinery: In the broader field of machinery manufacturing, boronized steel is used for components that need to endure heavy wear and tear, such as those in textile machines, gear systems, and general mechanical engineering applications. The BOROCOAT® process ensures that these parts maintain their integrity even under the most demanding conditions​.

Comparison Table: Boronized Steel vs. Boron Steel

Technical Details and Considerations

Boron steel typically contains boron in concentrations optimized for the required hardening properties. The addition of boron prevents the formation of pearlite and ferrite structures within the material, thereby increasing its hardness and strength. Common boron steels, such as ferroboron, contain relatively high levels of boron and are known for their exceptional wear resistance.

Boronized steel, created through the BOROCOAT® process, features a boron-infused surface layer with hardness levels up to 2,800 HV. This process is particularly effective for unalloyed and low-alloy steels but can also be applied to a wide range of other materials, including stainless steels and nickel-based alloys. The resulting boride layer offers exceptional resistance to abrasive wear, cavitation, and high temperatures up to 1000 °C.

Conclusion: Choosing the Right Steel for Your Application

When deciding between boron steel and boronized steel, consider the specific demands of your application. For newly manufactured parts that require through-hardening, boron steel offers unparalleled strength and wear resistance. Conversely, if you need to enhance the durability of existing components, boronizing with BOROCOAT® provides a robust surface layer without altering the core properties of the material.

At BorTec, our experts are ready to help you determine the best solution for your project’s requirements. Contact us today to learn more about how boron can transform your steel components into high-performance materials.