Chlorine based hot corrosion study of cold sprayed NiCrAlY coating

Abstract

In this work, the NiCrAlY coating was deposited by cold spray deposition technique on Fe based Superfer 800H superalloy. The cold sprayed coating was found to be dense and hard and adhered strongly to the substrate superalloy. In the present investigation, the cyclic hot corrosion behaviour of the coated and bare specimens under the Na₂SO₄–10%NaCl environment at 900°C is described. It is found that unlike bare superalloy, uniform, dense and adhered scale layer formed on top of the coated specimen. The various characterisation techniques X-ray diffraction, SEM/EDAX and elemental X-ray mapping were used to analyse the corrosion products. It was found that the coating deposited by this coating technique successfully provided protection to the substrate against the hot corrosion degradation by reducing the weight gain of the superalloy.

Keywords:

• Superalloy
• Coating
• Corrosion

Acknowledgement

The authors express their sincere thanks to Madam Narinder Kaur from Indian Institute of Technology Ropar, Ropar, Punjab, India, for her support in completion of this research work.

Notes

This paper is part of a special issue on cold spray technology