Al enrichment of carbon steels through weld overlay process for improved oxidation resistance

A simple method is described for enriching the surface aluminum concentration of carbon steel. The process of weld overlaying steel substrate with pure aluminum wire results in an aluminum concentration of ∼15–17 at.% (8–9 wt.%) for depths of ∼2 mm. The aluminum-enriched surface shows an improved oxidation and sulfidation resistance. The paper gives details of the process along with microstructural analysis and oxidation resistance improvement results.