The automatic analytical methods for boron and phosphorus in steels have been studied using Technicon Auto Analyser.
The experimental results were as follows;
(1) Phosphorus in steel was found to be automatically determined sucessfully by the adaptation of the established molybdenum-blue spectrophotometric procedures.
When the iron content is Lelow 50%, however, the violent evolution of SO₂ is caused by the remaining of much amount of sodium bisulfite which was not oxidized by ferric iron and makes it impossible to determine the phosphorus content due to the turbulence of the absorption curve.
The time required for analysis of 20 samples was 3 hours and remarkably shortened as compared with that by the manual analysis (about 7 hours).
(2) Boron in steel was found to be automatically determined successfullyby the adaptation of the established methylene-blue spectrophotometric procedures which involve thestrong phosphoric acid decomposition and the elimination of the interference from excess HF.
The time required for analysis of 20 samples was 2 hours and remarkably shortened as compared with that by the manual analysis.