Determination of the crystal structure of FeTiP-type precipitates in a few interstitial-free high-strength steels

The crystal structure of the FeTiP-type precipitates present in Ti + Nb interstitial-free high-strength (IFHS) and Ti-IFHS steels has been determined. Simple FeTiP has an orthorhombic structure with unit cell dimensions a = 5.816-5.821 Å, b = 3.731-3.745 Å and c = 6.554-6.569 Å. The presence of Nb in FeTiP-type precipitates does not alter the crystal structure but does increase the unit cell dimensions, especially the length of the c-axis. The unit cell dimensions in this case are a = 5.939-6.105 Å, b = 3.800-3.817 Å and c = 7.151-7.171 Å.