The microstructure and composition of the bond interface of titanium-steel explosion welds were investigated by means of optical microscopy and electron probe microanalysis after heat treatments between 923 and 1273 K. Heating at 923 K does not produce any intermetallic compounds, whereas heating at 1023 and 1273 K results in the formation of various intermetallic compounds and the solid solution phases. The diffusion paths at 1023 and 1273 K were interpreted by means of the FeTiC phase diagram assuming that local equilibrium is established at the phase boundaries.