Protection device for nut with anodized layer in flame brazing process

The invention discloses a protection device for a nut with an anodized layer in a flame brazing process. The protection device comprises a shell and a heat insulation gasket. The shell is composed oftwo semi-cylindrical shells which are symmetrically distributed, a semi-circular hole is formed in the top face of the shell, high-temperature ceramic is sprayed to the outer surface of the shell, andthe whole nut is wrapped in the shell in the mounting process. The heat insulation gasket is composed of two semi-circular ring bodies and is arranged on the upper end face of the nut during mountingto isolate the nut from the shell. According to the designed protection tool, the nut with the anodized layer is well protected in the flame brazing process, machining of the part is achieved, and the problems of welding protection and welding quality are thoroughly solved; and the high-temperature ceramic is sprayed to the surface of the stainless steel tool, the problem that the tool cannot betaken down when welded in th