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How is ferroboron used in steelmaking?

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A labeled diagram of the periodic table entry for boron shows its atomic number 5, symbol B, electron configuration, atomic weight range, and classification as a solid, weakly acidic, other nonmetal with a rhombohedral crystal structure at room temperature. — boron Properties of boron.

In steelmaking, ferroboron is used as an alloy to introduce small, precise amounts of boron into molten steel.12

Because ferroalloys generally have lower melting ranges than pure elements, ferroboron can be incorporated more readily into liquid steel to achieve a specific chemical composition. It is typically added in small quantities, usually ranging from 0.001 to 0.005 percent by weight.21

The primary purpose of adding boron in this form is to improve the hardenability of the steel. By increasing hardenability, boron allows for the production of a deeper hardened zone in the workpiece, even at lower cooling rates during heat treatment. Additionally, these alloying agents can permit tempering at higher temperatures, which helps generate better ductility while maintaining the desired hardness and strength of the final product.3