High temperature sulphidation of HVOF sprayed CeO₂ modified NiCrAlY coatings in H₂/H₂S atmospheres

Abstract

High temperature sulphidation is one of the most deleterious forms of surface degradation. In the present work, the high temperature sulphidation behaviours of high velocity oxyfuel sprayed NiCrAlY and NiCrAlYCe coatings on high pressure steels in H 2 -H 2 S mixtures were investigated. Results showed that the NiCrAlYCe coating provided much better sulphidation resistance than the NiCrAlY coating in the given environment. After adding minor CeO 2 , the outer layer of scales became compact and showed good adhesion, which decreased the sulphur vapour pressure inside the scale and promoted the formation of more protective inner layer of sulphospinels (Cr, Ni)Al 2 S 2 .

Performance of cold spray coating in industrial medical waste incinerator

“…The nickel based superalloys cannot be prevented from hot corrosion for long time in the aggressive environment of Na, Cl and S at high temperature. Researchers [3][4][5][6][7][8][9] found that one of the economical and viable ways to overcome these problems is the use of thin high temperature, erosioncorrosion and wear resistant coatings. The base material will provide the required mechanical strength and coating will resist the erosion-corrosion.…”

Chlorine based hot corrosion study of cold sprayed NiCrAlY coating

“…1 Hence, it is required to have a composite system of a base material that would provide the requisite mechanical strength along with a surface layer to sustain in the high temperature corrosive environment. The protective coatings on the metal/alloy have been examined by researchers [2][3][4][5][6][7][8] to protect the substrate from hot corrosion. The various coatings are able to increase the life of the substrate alloys; however, the chlorine based power producing plants are running at low efficiency.…”