PIXE and SPM analysis of V, Cr, Cu and Bi in nodular cast iron

Abstract

The nodular cast iron was prepared with the same nodularizing process in which the elements V, Cr, Cu and Bi were added respectively. The graphite phase was extracted from the nodular cast iron to measure the trace elements in it. It was made into a thick target and measured by proton induced X-ray emission (PIXE) analysis. The contents of V, Cr and Cu were 3, 40 and 14 ppm respectively in the graphite, as the element was separately increased to 2100, 5000 and 2500 ppm in the matrix. Therefore, V, Cr and Cu do not intrude the graphite as the contents of these elements are lower and have no obvious effect on the nodularization. Bi, which belongs to the antinodular elements, easier intrudes into the graphite than others. The content of Bi in graphite was 74 ppm and the nodularizing rate went down by 34% when it was 200 ppm in the matrix. The distributions of V, Cr, Cu and Bi in the sample were measured using a scanning proton microprobe (SPM) to research the properties of these elements further. The results showed that most of the V, Cu and Cr distributed in the matrix. Some of the Cu intruded into the graphite, some existed in the matrix yet as Bi was increased to 200 ppm. These results of SPM agree with that of the PIXE analysis.