"Why do we Need to Measure Trace Elements in Steel ?"

With the increase in performance requested by users in the last twenty years, steel makers have had to improve their melting operations dramatically. Numerous chemical elements are now controlled or eliminated at levels of 50 ppm and below. Sinces it is difficult to give a rating to the importance of these elements, this paper lists a series of them alphabetically, and comments on them, non-exhaustively. Control of these substances has led to improvements in : - Mechanical characteristics at room and elevated temperatures, as well as creep resistance. - Toughness and fracture mechanics at low temperature. - Practical weldability - Hot and cold formability - Corrosion resistance in numerous media