Microstructural aspects of phosphorus grain boundary segregation in low alloy steels

The influence of microstructure on phosphorus grain boundary segregation in 2.6Cr-1Mo-0.3V low alloy steel was investigated. Measurement of the phosph orus grain boundary concentration and characterization of the steel microst ructure (substructure) were performed by means of Auger electron spectrosco py (AES) and transmission electron microscopy (TEM). It was found that the phosphorus grain boundary segregation during the aging of the steel at 773 K is faster in as-tempered microstructure than in as-quenched material. The lower dislocation density and the indirectly evidenced lower carbon conten t in ferrite matrix were considered to accelerate the kinetics of phosphoru s segregation. (C) 2001 Elsevier Science B.V. All rights reserved.