Investigation of the grain boundary elemental composition of the low-alloy steel

An Auger electron spectroscopy study of the fracture surfaces of low-alloy CrMoV steel is carried out. The samples are subjected to several treatments including annealing in an elastically-stressed state. Part of the samples are doped with hydrogen in order to stimulate brittle intergranular fracture. The samples are fractured in a special Auger spectrometer chamber by tensile test. The grain boundary segregation composition changes in dependence on the preliminary treatments. Phosphorus segregation on the ductile fracture surface is found. The equation of segregation kinetics is used for the estimation of the effect of tensile stress on the diffusivity of phosphorus during low-temperature annealing at 340 degrees C. The effect of fracture surface roughness on the Auger electron spectroscopic data is estimated by model calculations.