Fluorescence test: immerse the plate or weldment in a mixture of kerosene or mineral oil for a few minutes. After the surface is dried, mineral oil remains in the defect, sprinkle with magnesium oxide powder, remove the magnesium oxide powder. When the ultraviolet light is emitted from the mercury quartz lamp, the residual phosphor will emit light and defects will be revealed.It has the advantage as follow:
(1) Defects show bright fluorescence and high visibility under black light.
(2) The excess penetrant on the surface of the part can be directly removed by water. Compared with the post-emulsification type penetrant inspection process, it has the advantages of simple operation and low inspection cost.
(3) For the inspection of parts with rough surfaces and parts with complicated shapes, it is possible to detect defects in the corners, keyways, threads of the parts.
(4) High-sensitivity water-washing fluorescer can detect very fine defects