The quality inspection of coating process mainly includes the following steps:
(1) Inspection before coating of steel pipe: no crack, debris and other quality defects, such as no grease and flux on the surface, etc.
(2) Surface inspection of steel pipe after shot blasting: the surface roughness of the steel pipe should reach 65 to 90 microns.
(3) Inspection of spraying process: the wet film thickness meets the requirements, and the appearance should be continuously flat and without flow.
(4) Inspection after curing: after coating, the surface of the steel pipe is visually inspected, and the coating color is uniform and continuous.