Abstract
To determine the sulfide species evaporated from iron alloys during vacuum melting, mass spectrometry was used. A small furnace was wound with tungsten wire and was coated with alumina. Specimens of materials to be investigated were placed in the furnace located close to the ion source of the mass spectrometer. The alloys investigated were Fe-C-S alloy (2.70%C, 1.32%S), Fe-Si-S alloy (3.40%Si, 0.5%S), Fe-C-Si-S alloy (3.42%C, 2.73%Si, 0.51%S), Fe-Al-S alloy (2.42%Al, 0.49%S) and Fe-S alloy 0.20%S). Temperature was measured by means of an optical pyrometer, and the range was 1000- 1400°C.
In the Mass spetr* of Fe-C-S alloy the ions S+, S+2, CS+ and CS+2 were found and the proportion of S+ ion was, greatest. SiS+, S+ and S+2 ions were found in the mass spectra of Fe-Si-S alloy. In the mass spectra of Fe-C-Si-S alloy, SiS+, CS+, CS+2, S+2, S+ ions were found and of these ions the proportion of SiS+ is large compared with the others, and, in addition to the ions mentioned above, SiS+2 was also found at the high temperatures (above 1300°C). The ions S+ and S+2 were found in the mass spectra of Fe-Al-S and Fe-S alloys.
