抄録
Non-metallic inclusions in steel are closely connected with quality of steel, and it is extremely important for the investigation of pecuriality and effects of added elements of steels to understand precipitated shapes, distribution and quantities of inclusion.
In this report, the results of fundamental studies on determination of nonmetallic inclusions in steel by fluorescent X-ray analysis are described.
In the experiments, non-metallic inclusions were isolated by hot nitric acid or iodire-methanol method, and which were supported on the suitable filters to be determined by the fluorescent X-ray analyzer Fluroprint MK-II The analyzed elements are Si, Al, Fe, Mn and Cr.
The results were summarized as follows;
(1) According to the surface observarion of filters, which were treated with NaOH solution (3%). by scanning electron microscope, Membran filter MF3O was found to be the most suiable as support for residues.
(2) In the iodine-methanol method, the amorphous carbon is isolated with inclusions simultaneously and interferes in the fluorescent X-ray analysis. But the amorphous carbon can be removed from residues by ignition in Platinum cruciLle at a temperature below 400°C.
(3) Fluorescent X-ray intensities of Si and Al are affected by Fe, Mn and Cr, but in the case of more than 200μg of Si or Al, effect of 1000μg of Fe+Mn is negligible.
(4) As compared with general chemical analysis on Al2O3 inclusion in Al-killed carbon steel, average and standard deviation of difference were 0.0001% and 0.0006%.
