Corrosion-resistant sprayed coating, method for forming same and spraying device for forming same

A method for forming a corrosion-resistant sprayed coating, wherein a corrosion-resistant alloy sprayed coating comprising aluminum that has a porosity of 1% or less, with the surface thereof unsealed, and that forms a microstructure with a grain size of 10 μm or less, is formed on a substrate surface, using a thermal spray gun having a function wherein a flame including melted material particles is jetted toward a substrate, and the flame is partitioned from the open air in an upstream region on said jet path, and a function wherein, in a downstream region, the material particles and the flame are forcibly cooled by a jet-gas or jet-mist before reaching the substrate,

• and although thermal spraying is performed with a corrosion-resistant alloy material comprising aluminum as the material particles, neither laser irradiation nor extrusion processing are performed,
• wherein at least some of the microstructure includes a nanostructure with a submicron grain size, and
• wherein the corrosion-resistant alloy sprayed coating comprises magnesium of 0.3 to 15 mass %, oxygen of 0.2 mass % or less, and a remaining balance of aluminum.