When the flaws on the blades are drawn, methods such as color flaw detection, magnetic particle flaw detection, and phosphor flaw detection can also be used.Needless to say, the easiest and most effective way to check the damage of the blade is to observe directly with the eyes. Among them, the coloring method is the most convenient, low cost, and widely used. Phosphor detection: Coat the blade with phosphor and wipe it off.
In this way, the scar on the injured blade can be found. You can check the blade for cracks and scars with the naked eye through a magnifying glass of more than 10 times. The top of each impeller becomes a magnetic pole and then coated with iron powder. The magnetic particle inspection method winds the fan rotor or impeller on a wire, and passes direct current to make the impeller or rotor generate a magnetic field.
After the staining method is used to clean the fouling on the blades, apply red penetrant to the parts that need to be inspected.Move the rotor or impeller to the dark room for observation. If the blade has a crack, two different polarities will be produced at the gap of the crack, thereby attracting the iron powder. There are cracks where the phosphor cannot be wiped off and will emit light.
The penetrant is dissolved in Sudan red with a mass fraction of 1010 in 60% kerosene, 10% turpentine, In the 30% water and acid ester mixture, after a while, wipe it with clean gauze, and then coat with white developer (5% zinc white by mass, mix well with 30% collodion Liquid, and then add mass fraction 20% benzene, 50% acetone dilution), after drying, if there are cracks, it will show obvious red lines on the white background
