Oxidation and hot corrosion behaviors of HVAF-sprayed conventional and nanostructured NiCrC coatings

doi:10.1016/S1003-6326(08)60421-5

Transactions of Nonferrous Metals Society of China

Volume 19, Issue 5, October 2009, Pages 1151-1160

https://doi.org/10.1016/S1003-6326(08)60421-5 Get rights and content

Abstract

The oxidation and hot corrosion behaviors of HVAF-sprayed conventional and nanostructured NiCrC coatings were studied. The oxidation experiment was conducted in air, and the hot corrosion was conducted in the Na₂SO₄–30%K₂SO₄ environment, in the temperature range of 550–750 °C for periods up to 160 h. The corrosion kinetics was tested with the thermogravimetric method. The corrosion products were characterized by scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffractometry (XRD). As indicated by the results, both types of coatings possess high corrosion resistance, especially the nanostructured NiCrC coating. The enhanced grain boundary diffusion in the nanostructured coating not only promotes the formation of a denser Cr₂O₃ scale with a higher rate, but also helps to mitigate the Cr depletion at the metal/scale interface. The less porosity of the nanostructured coating is also thought to be beneficial to the anti-corrosion properties.

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: Foundation item: Project(2002AA331080) supported by the National High-tech Research and Development Program of China

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Oxidation and hot corrosion behaviors of HVAF-sprayed conventional and nanostructured NiCrC coatings

Abstract

Surface and Coatings Technology

Thin Solid Films

Scripta Materialia

Mater Sci Eng A

Scripta Materialia

Progress in Materials Science

Surface and Coatings Technology

Materials Chemistry and Physics

Surface and Coatings Technology

Trans Nonferrous Met Soc China

Acta Materialia