Influence of powder feed rate on corrosion and wear properties of Fe-based HVAF coatings

20th Chemnitz Seminar on Materials Engineering - 20. Werkstofftechnisches Kolloquium

Bobzin, K.^1 ; Öte, M.^1 ; Knoch, M.A.^1 ; Sommer, J.^1

Institut für Oberflächentechnik, RWTH Aachen University, Germany^1

关键词: Chemical polarizations;    Coating thickness;    Corrosion and wears;    Corrosion behaviour;    Crack-free coatings;    Feedstock materials;    High velocity air fuels;    Surface protection;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/373/1/012012/pdf
DOI  :  10.1088/1757-899X/373/1/012012

来源: IOP

【 摘 要 】

Large-area applications, such as Yankee cylinders for paper machines, are often exposed to corrosion/wear, and therefore require adequate surface protection. The goal of this study is to develop a cost-efficient coating system that offers comparable protection to the industrially established Fe-based coating systems produced by wire arc spraying (WAS). Cost efficiency is to be achieved by using an economically priced, novel Fe-based feedstock material, the high velocity air-fuel (HVAF) process as well as a coating thickness reduction. In this study, the feedstock material FeCrB/WC-Co with the grain size fraction -32 +11 μm was investigated. Two coating thicknesses dct≈ 120 μm and dct≈ 240 μm and two different powder feed rates p = 40 g/min and p = 200 g/min were considered. An industrially established WAS FeCrBSiMnC coating system was used as reference. To examine the microstructure, cross sections of the coatings were prepared and investigated with a light microscope. Electro chemical polarization and pin-on-disc- (POD) tests were performed to investigate the corrosion and wear properties of these coating systems. Furthermore, XRD measurements were used to investigate the phase composition. The results show that a dense and crack-free coating can be produced with a powder feed rate of p = 200 g/min and that the powder feed rate p has a significant influence on the corrosion behaviour.