[Problem] To provide a corrosion-resistant coating that exhibits greater corrosion protection in saltwater environments and the like than was conventional, a method for forming the same, and a device for forming the same. [Solution] A corrosion-resistant alloy coating is formed on a substrate surface by: a) 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 (which is to say the region in which the material particles are melted), and a function wherein, in a downstream region (the area continuing from the upstream region), the material particles and the flame are forcibly cooled by a jet-gas or jet-mist before reaching the substrate; and b) using a corrosion-resistant alloy material comprising aluminum, for the material particles.

A thermal spraying method for coating an inner surface of a cylinder of an internal combustion engine or of a piston engine. The method includes applying a thermal spray layer onto the inner surface of the cylinder so as to obtain a coated inner surface, inserting an optical sensor device into the cylinder, and scanning the coated inner surface via the optical sensor device in order to detect at least one of a ridge and an indentation in the thermal spray layer. A thermal spray torch for the method includes an optical sensor device which is inserted into the cylinder and to scan the coated inner surface of the cylinder so as to detect at least one of a ridge and an indentation in the coated inner surface.

[Problem] To provide a corrosion-resistant coating that exhibits greater corrosion protection in saltwater environments and the like than was conventional, a method for forming the same, and a device for forming the same.

[Solution] A corrosion-resistant alloy coating is formed on a substrate surface by: a) 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 (which is to say the region in which the material particles are melted), and a function wherein, in a downstream region (the area continuing from the upstream region), the material particles and the flame are forcibly cooled by a jet-gas or jet-mist before reaching the substrate; and b) using a corrosion-resistant alloy material comprising aluminum, for the material particles.