Networks of metal nanoparticles trigger alloy corrosion

摘要

Oxide scale that develops on the outer surface of metal alloys at high temperatures is generally expected to protect the alloys from continued corrosion and degradation such as sulfidation, carburi-zation, and metal dusting. Corrosion will occur, however, when the integrity of the scale is compromised by an intruding substance (such as carbon deposit at high temperatures) that breaks down the scale and attacks the underlying alloy. Until now, scientists considered carbon-bearing molecules, such as carbon monoxide (CO) and carbon dioxide (CO_2), to reach the underlying substrate through pores or cracks in the oxide scale, but researchers Zuotao Zeng, Zhonghou Cai, Seth Darling, and Ken Natesan at the U.S. Department of Energy's (DOE) Argonne National Laboratory (Argonne, Illinois) have discovered another explanation for the carbon diffusion and subsequent alloy corrosion.