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To investigate the corrosion behavior of NiCrAl-NiC sealing coating in high-temperature molten salt environments，NiCrAl-NiC sealing coating was prepared using atmospheric plasma spraying technology. By measuring the weight loss of NiCrAl-NiC sealing coating，the dynamic changes of the coating were studied. The thermal corrosion behavior of NiCrAl-NiC sealing coating in a mixture of thiochlorate（75% Na2SO4 + 25% NaCl）at 650 ℃ was discussed using scanning electron microscopy（SEM），X-ray diffraction（XRD），laser confocal microscopy，and other methods. The results show that after 10 h of hot corrosion experiments，the NiCrAl-NiC sealing coating exhibites a rapid weight gain state，with a weight gain rate of 32.041 mg2·cm–4·h–1. After conducting a 20 h hot corrosion experiment，the coating experienced weight loss due to the detachment of the surface oxide film. After 30 h of hot corrosion，the growth of the facial mask on the coating surface covers the entire coating. The surface morphology of the coating is uniform，and the surface pores are reduced，which can play a good role in protecting the substrate. Under the protection of a complete oxide film，the mass change rate of the NiCrAl-NiC sealing coating after a 40 h hot corrosion experiment is 0.064 mg2·cm–4·h–1. Through XRD testing，it is found that the composition of the oxide film on the surface of the coating after hot corrosion is mainly NiO and NiCr2O4. During the hot corrosion process，the spinel structure of NiCr2O4 hinders the hot corrosion of the coating，which is the main reason for the slow corrosion process of the coating.

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As an important component of aviation turbine engines, abradable sealing coatings have the function of protecting turbine blades and improving engine efficiency. However, Abradable Sealing Coating systems (ASCs) are often damaged by corrosion in their applications, which may cause safety accidents. This article uses atmospheric plasma spraying technology to prepare NiCrAl–NiC ASC system, which is divided into three layers with a porous structure on the top. In order to fully explore the corrosion behavior of NiCrAl–NiC ASC system, corrosion tests were conducted on the ASC system using immersion method. The corrosion potential of this coating system is −0.96V, and a low corrosion potential indicates that the coating is more prone to corrosion. On the other hand, its current density is 51.64 × 10−6 A cm−2, indicating a slower corrosion rate of the coating. After immersion for 600 h, the corrosive medium Penetrated into the interior of the coating, forming interlayer corrosion. The electrochemical impedance results showed that the corrosion process of the coating was divided into three stages, and the impedance fitting results were consistent with the changes in coating porosity during the immersion process. The corrosion products of the coating are oxygen-containing compounds of various metal elements, including Al 2 O 3 , Al (OH) 3 , NiO, Ni(OH) 2 , and Cr 2 O 3. The porous, multi-layered, and multiphase characteristics of coatings result in their unique corrosion behavior. • The multi-layer structure of coatings affects the corrosion process. • Corrosion penetrates into the interior of the coating. • Porosity is a key factor in the corrosion process. • OCP results show that the coating structure is reasonable. [ABSTRACT FROM AUTHOR]