Determination of carbon in iron-silicon-aluminum alloy by high frequency induction combustion infrared absorption method
Iron-silicon-aluminum(Fe-Si-Al)alloy is an important magnetic material compose d of silicon(7%-9.5%),aluminum(5%-6.5%)and iron matrix.The content of carbon impurity will reduce the magnetic conductivity of Fe-Si-Al alloy,and should be accurately monitored.At present,there are no standard analy-sis methods for carbon in Fe-Si-Al alloy,and the application studies are in lack.In this study,the method for the determination of carbon content in Fe-Si-Al alloy by high frequency induction combustion infrared absorption method was established.The effect of sample mass and flux on the determination results was in-vestigated.The following conditions were obtained:0.2-0.3 g of sample was accurately weighed and then fused with ternary flux(1.5 g of tungsten+0.20 g of iron and 0.30 g of tin).The calibration curve of in-strument was established using the certified reference materials of steel,and the linear correlation coeffi-cient was 0.999 1.The content of carbon in the certified reference materials of steel was analyzed using the calibration curve,and the found results were consistent with the standard values.The limit of detection was 6 μg/g,and the limit of quantification was 21 μg/g.The Fe-Si-Al alloy with carbon of 0.005%-0.020%was determined according to the experimental method.The relative standard deviations(RSDs,n=6-7)of deter-mination results were less than 8%,and the recoveries were between 89%and 110%.
high frequency induction combustioninfrared absorptioniron-silicon-aluminum alloycarbontungsten-iron-tin ternary flux