EFFECTS OF THE ALLOYING ELEMENTS TI, NB, MO AND V ON THE GRAIN-BOUNDARY SEGREGATION OF P IN IRON AND STEELS

Interaction of Ti and Mo with P was investigated in detail, and also the interaction with the closely related elements Nb and V, utilized as important alloying elements in steels. All these elements also form more or less stable carbides. Thus the interaction of M equals Ti, Mo, V and Nb with P is affected by the presence of carbon and dependent on the thermodynamics and kinetics of carbide formation. Therefore, not only the systems Fe-M-P but also the systems Fe-M-C-P were studied using AES for grain boundary analysis and in some cases field ion microscopy combined with atom probe microanalysis was applied for identification and analysis of precipitates and eventual clusters.