Quantitative analysis of trace elements in steel by ion micro analyser using ion implanted iron as standards

The principle and the characteristics of Ion Micro Analyser (IMA) were explained. Then, standard samples of steel containing trace elements therein were prepared by ion implantation and analyzed quantitatively by means of IMA. BO2- was used as a secondary ion so as to increase the analytical sensitivity and was normalized by 16O-. An analytical curve was determined by analyzing the depth direction of boron. It was found that the analytical curve was appliable to wide boron concentration ranging from 10-5 to 100 % by weight. The detection limit was 50 ppb by weight of boron. Using secondary BO2- image, the precipitates in steel containing 10 ppm of boron and the grain boundary segregation were captured. Furthermore, the latter was quantitatively evaluated by applying the analytical curve. (Kubozono, M.)