1. Dye penetrant imaging agent, the main component of the imaging agent is magnesium oxide particles, if it is wet imaging agent and suspension agent, these are not harmful to the human body. But the suspension is flammable, to pay attention to fire.
2. The basic principle of fluorescence penetration testing
The magnesium oxide powder permeated with mineral oil can emit yellow-green fluorescence under the irradiation of ultraviolet light, so that the defects can be exposed, as shown in the following diagram. Because there is still a small amount of magnesium oxide powder in the gap of the defect, the welding piece is illuminated by a mercury quartz lamp in a dark room. Under the action of the ultraviolet radiation emitted by the mercury quartz lamp, the phosphor which penetrates into the defect emits light, the defect is clearly shown.
3. Fluorescent testing.
Choice of imaging agent:
1) good adsorption capacity:
2) easy to be washed, no corrosion to the workpiece;
3) non-fluorescent substances;
4) harmless to human body.
General use of magnesium oxide powder (MgO) , magnesium carbonate powder (MgCO3) powder, quartz powder, etc. . Magnesium oxide powder is common.
4. The application of magnesium oxide in fluorescent osmotic solution
1. Part requirements before inspection:
1.1 the parts under inspection shall be thoroughly cleaned to remove oil, rust, chips, paint layer, water stains and other contaminants.
1.2 for parts that have been tested for colouring, all the colouring agents should be cleaned as contamination of the defect by the colouring penetrant will cause fluorescence to be extinguished, resulting in unreliable fluorescence test results.
2. How to use the osmotic solution:
2.1 penetration and cleaning: immerse the clean and dry parts in the fluorescent liquid (or brush and spray the fluorescent liquid on the parts) for 10-15 minutes. Take out the parts and drop them on the empty shelf and turn them over, make sure that the surface permeating fluid runs out, and then wash it at the water temperature of 20-40 °C, (adjust the air-water spray gun to produce a suitable low-speed jet flow, the nozzle is at least 30cm away from the part, the pressure is about 0.35 kg/CM2, and the concave parts such as the groove and the inner channel can be cleaned by the nozzle with angle or immersed in the agitated water, or the two methods can be used in combination) . In black light inspection, the surface of the parts should be no residual background fluorescence color.
2.2 drying, imaging and inspection: the parts shall be dried in a hot air cycle oven for a period of time which varies with the geometry, size, material properties and initial temperature of the parts, but the drying time shall be maintained, the temperature should not exceed 85 ° C, after drying should be coated as soon as possible imaging powder (light magnesium oxide) , powder covering 10-15 minutes, and then UV lamp start 10-15 minutes after the start of inspection.
Storage and transportation:
1. Do not damage the package during storage and transportation. Do not over-push the package.
Keep in a dry place to prevent rain.
3. No fireworks.