On Titanium Carbide

Study of nonmetallic inclusions in iron and steel with an electron microscope. I

Abstract

The titanium carbide in titanium-containing steel was studied with an electron-microscope and by means of electron diffraction. The result was compared with the data of chemical analysis and the crystal grain size of the steel. There were found some close relations among them.
Changes of particle size of precipitates in accordance with different heat-treating temperatures and contents of solutes in the steel were observed. In the steel A (C=0.085%, Ti= 0.22%) the particle size of the precipitate was about 100 Å at 900.. and 50mμ-μ at 1100... On the other hand, in the steel B (C=0.32%, Ti=0.46%), several microns particles were observed at various temperatures.
The lattice constant of titanium carbide was decreased gradually from 4.33 Å to 4.27 Å, when the temperature rose from 900.. to 1300... It was considered that the composition of the carbide was changed with heat-treating temperatures.
There were found a close relation between the crystal size of the steel and the quantity of precipitates. It was presumed that the quantity of precipitated carbide was a dominant factor for the crystal grain size in Fe-Ti-C system.