A fundamental study of isolation and determination of titanium compounds in steels was carried out by means of hydrochloric acid, sulphuric acid, phosphoric acid, bromine-ester, iodine-alcohol, and potentiostatic electrolysis methods.
The results are as follows:
1. According to the experimental results on chemical behaviors of various synthesized titanium compounds,
(1) Titanium carbide, TiC is very stable in mineral acids, but easily decomposed in oxidizing reagents.
(2) Titanium nitride, TiN is decomposed in nitric acid, while in other mineral acids it is slightly decomposed at elevated temperatures.
(3) Titanium oxides, the higher the valency of titanium, the more stable the oxide is. And ferrous titanium oxides are attacked in mineral acids.
(4) Above-mentioned titanium compounds, TiC, TiN and titanium oxides, are very stable in iodinealcohol and bromine-ester.
(5) Titanium sulphides, TiS and Ti3S4 are unstable in mineral acids and easily decomposed in iodinealcohol, bromine-ester and other oxidizing reagents.
2. Carbide, TiC in steels can be extracted by any methods quantitatively.
3. Nitride, TiN in steels is also extracted by any methods but the isolated TiN is gradually decomposed in mineral acids.
4. For isolation of titanium compounds in steel, the electrolytic method is desirable, because in acid and halogen-organic solvent the unstable compounds such as TiO, 2FeO·TiO2, TiS and the precipitates of very fine particles are attacked slowly.
5. Chemical separation of synthesized titanium carbide, nitride, oxide and sulphide is possible, but chemical behavior of inclusions and precipitates in steels are affected by their size, disorder of their lattice and coexisting elements so that accurate separation is very difficult.