Abstract
Heretofore, the chemical analysis of boron in high alloy steel has been impossible; however, the author has now devised a new method for the determination of boron. The procedure is as follows:
The sample is decomposed with aqua regia or other suitable acid, and the solution is transferred into a distilling flask. Sulfuric acid and phosphoric acid are added, and the mixture is evaporated by heating until white fumes are evolved, thus dehydrating it and driving off the acids other than the phosphoric acid and the sulfuric acid used in the decomposition of the sample.
The flask is then connected to a distilling apparatus and distilled with methanol in order to distill boron as methyl borate. This step in the procedure is repeated twice. The distillate is made alkaline with alkali and evaporated to dryness by heating at 80?90°C. The residue is taken up in concentrated sulfuric acid and heated for 10 minutes at 70±5°C. with carmine solution for coloration of boron. The boron is then determined by the light absorbency method.
This method is based on experimental evidence obtained by the author and described in another paper that boric acid in acid solution is not volatile. For the decomposition of a sample, nearly all acids could be used, and the difficulty of dehydration experienced by the usual method could be overcome easily by heating. Thus, the method of estimation of boron in a high alloy steel as well as in a simple steel became easy. Satisfactory results in the determination of boron in high alloy steel can be obtained, as indicated in Tab. 2.
