Investigation on Determination of Titanium Precipitates in Steel by Secondary Ion Mass Spectroscopy

Analytical conditions were examined for the determination of titanium precipitates in steel as titanium carbide and titanium nitride by secondary ion mass spectroscopy. Characteristic polyatomic ions related to the compounds were sought by comparison of the intensity of polyatomic ions for various samples. The intensity of polyatomic ions were calculated by fitting the SIMS spectra to the relative isotopic abundance of each ion using non linear least square method. The polyatomic ions TiC+ and Ti2C+ were selected for the characteristic ions of titanium carbide and TiN+ and Ti2N+ for titanium nitride because of higher intensity and good reproducibility. The compressed disks of mixed powder of iron, titanium carbide and titanium nitride, with a few μm diameter, enble the determination of titanium carbide and nitride to less than 1 wt%.