Visual information concerning the procedure for oxidation of phosphorus and spectrophotometric FIA for advanced iron and steel analysis

Abstract

Phosphorus is generally considered to be an undesirable impurity in iron and steel, since it tends to cause their brittleness at low temperature. On the other hand, phosphorus is sometimes added into iron and steels in order to improve their machinability and/or atmospheric corrosion resistance. Therefore, the concentration of phosphorus in steel and iron must be strictly controlled. Massive numbers of people in the baby boom generation have been recently retiring from their work in Japan. In such a situation, there is great concern about the loss of their skills in many industrial fields. The skills of steel chemical analysis are also faced with this problem. In this study, the procedure for perchloric acid oxidation of phosphorus with heating in iron and steel analysis (described in JIS G 1214:1998) was visualized for successful skill transfer. Furthermore, the subsequent molybdenum blue method for phosphate was automated by a flow injection analysis (FIA) system. After the acid decomposition of two certified reference materials of steels (D 183-1 and D 079-2 given by BAM: Bundesanstalt für Materialforschung und–prüfung), the resulting solutions were analyzed by the proposed FIA method. The analytical results were consistent with the certified values, respectively.