DOI: 10.1007/s11085-005-5716-z Oxidation of Metals, Vol. 64, Nos. 1/2, August 2005 (© 2005) Influence of Laser Welding on the Alumina Growth on a Thin FeCrAl-RE Foil at High Temperature H. El Kadiri, ∗†‡ R. Molins, ∗ Y. Bienvenu, ∗ and M. F. Horstemeyer † Received July 21, 2004; revised March 22, 2005 We study isothermal oxidation of laser welded FeCrAl-RE samples containing specific fractions of seams in a bead-on-plate configuration at approximately 900 ◦ C using thermogravimetric analysis (TGA), field emission scanning electron microscope (FEG-SEM), transmission electron microscope (TEM), electron probe microanalysis (EPMA) techniques. An important reduction in the alumina-growth rate over the fusion zone compared to the base material occurs at 900 ◦ C, thereby, suppressing the discontinuous increase in mass gain commonly observed for alumina-forming alloys when the temperature decreases from 1000 ◦ C to 900 ◦ C. This phenomenon is mainly related to the concomitant dramatic chromium carbide precipitation at the fusion zone/oxide film inter- face and possible earlier injection of the rare earth elements into the oxide layer. On one hand, chromium carbide precipitation, which is linked to the laser melting-induced high free carbon, contributes to improve the effective- ness of the diffusion barrier provided by the thermally growing scale. On the other hand, due to their initial high enrichment at the fusion zone surfaces, rare earth elements can penetrate in the oxide layer and promote the elimina- tion of detrimental phase transformation of metastable platelets (γ,θ -Al 2 O 3 ) to α-Al 2 O 3 during the initial stages of oxidation. KEY WORDS: Laser welding; metastable alumina; α-Al 2 O 3 nucleation; kinetics; transfor- mation; interface; chromium carbides; grain growth; thickening of the platelets; reactivity anomaly. ∗ Ecole des Mines de Paris, Centre des Mat´ eriaux, CNRS UMR 7633, BP 87, 91003 Evry, France. † Center for Advanced Vehicular Systems, Mississippi State University, MS 39762-9627 USA. ‡ To whom correspondence should be sent. e-mail: elkadiri@cavs.msstate.edu 99 0030-770X/05/0800–0099/0 © 2005 Springer Science+Business Media, Inc.