Surface and Grain Boundary Segregation on and in Iron and Steels

Abstract

The equilibrium segregation of the elements A=C, Si, Sn, N, P, O, and S was studied for binary systems Fe-A in the stability range of the α-solid solution using surface analytical methods. On the surfaces ordered structures were observed by LEED and surface concentrations were determined by AES in dependence on bulk concentration and temperature. The chemical binding state was characterized by XPS. In grain boundaries the segregation of P and Sn was determined by AES on intergranular fracture faces after equilibration at elevated temperatures and fracture in UHV. Effects of alloying elements, especially C, on grain boundary segregation are described. Correlations of surface and grain boundary segregation with the chemical and mechanical behavior of steels are shortly discussed.