Boron in Steel: Part One
At the atmospheric pressure and temperature of 0°C boron is a solid material. Boron optimum quantity which has to be added in the steel to achieve maximum hardenability, based on experience is about 0.0003 to 0.0030% B.
Boron is supplied to steelmakers as ferroboron or as one of several proprietary alloys. Choice of addition depends, as always, on steelmaking practice, product mix and volume, individual operators` experience and preference, and price.