Note on the determination of boron in steel and ferro-boron

Generally 0.008% or even less of boron is added to steel for grain refining and increasing its hardenability. Difficulty arises for the determination of such a small amount of this element in presence of the prepondarent amount of iron by any of the existing methods. Two methods are known for the isolation and determination of boron in steel. Tschischewski² separated iron with a mercury cathode and titrated with sodium hydroxide, first in the presence of methyl orange and then of phenolphthalein. Lundell et al. isolated boric acid from steel as methyl borate and titrated by use of colour indicators. Both the processes have limitations; cathodic separation of iron is not always complete and separation of boron as methyl borate is cumbersome.Alloy Steels Plant, Durgapur 8.