SIMS characterisation of aluminum-alloyed hot isostatic pressed steel

Recently, interest in steel alloyed with similar to 1% Al increased. These materials are expected to show a higher resistance against oxidation at hig h temperatures which will improve their performance when used as high-speed -steels, Furthermore, efforts have been made to combine the advantages of A l-steels with those of powder-metallurgic methods like hotisostatic-pressin g (hip). This should result in a better macro- and microscopic homogeneity of the distribution of all compounds, yielding less waste-production and a longer life-time of products. In order to gain deeper insights in the process of "hipping" of the conside red material and to see the distribution of both main as well as trace comp onents, 2D and 3D-SIMS measurements of the material were performed before a nd after having undergone the hip process. The measurements showed enrichments of Na, K, Mg, Ca, and S at the particle boundaries before as well as after the hip-process. In the hipped material , the enrichments are significantly stronger in the spatial domains in-betw een larger particles. They also reveal, that the concentration of C is not equal in all particles and that the particles are covered with an Al2O3-lay er which is not dispersed by the hip-process. There were also found small ( similar to 50-100 nm) nitride-precipitates before as well as after the hip- process.