The ultimate aim of casting production is to obtain qualified castings. The quality of a casting part depends on the strict implementation of the requirements of each process, from the preparation of raw materials, alloy melting, moulding, pouring, and sand-falling to cleaning and storage, through more than a dozen processes.
As an effective means of quality control, casting inspection occupies an extremely important position in the quality assurance activities of research and production, including the safety, reliability and service life of castings.
There are many methods used for non-destructive testing of castings, the most commonly used are magnetic particle flaw detection, fluorescence detection, ultrasonic flaw detection and ray flaw detection.
The use of permeable mineral oil of magnesium oxide powder under ultraviolet light can emit yellow-green fluorescence characteristics, so that the defects revealed, as shown in the following chart "fluorescent liquid penetration flaw detection basic principles".
As there is still a small amount of magnesium oxide powder in the gap of the defect, the welded parts will be irradiated with a mercury quartz lamp in the dark room, under the effect of ultraviolet radiation emitted by the mercury quartz lamp, the fluorescent powder infiltrated into the defect glows, and the defect is clearly shown.
The specific practice is to apply the fluorescent liquid to the surface of the weld, if there is a defect on the surface of the weld because the fluorescent liquid has a strong penetration ability, so it can quickly penetrate into the crack, then wipe the surface of the part clean, in the dark room with mercury quartz lamp irradiation, then the fluorescent powder infiltrated into the defect under the action of ultraviolet light will glow, the defect is shown.
In order to ensure the quality of the castings, Tianhe Casting Group invited a flaw detection equipment company to customise a fluorescence penetration inspection line for the inspection of 40 pieces, up to 50kg, by means of a suspended spray, for the detection of non-loose hole type surface opening discontinuities in the parts.
The line is set up in accordance with ASTM-E1417-05, JBT 8466-2014, the relevant provisions of the penetrant inspection standard. The production line mainly consists of a loading station, high-pressure dust removal station, penetration station, drip station, cleaning 1 station, cleaning 2 stations, cleaning 3 stations, drying station, inspection station, discharging station, etc.; supporting and auxiliary facilities consist of electrical control system, hot water supply system, hot air supply system, ring track conveying system, etc.
Process flow.
Feeding → high pressure dusting → infiltration → blowing → dripping → 1st rough cleaning →2nd rough cleaning → fine cleaning → blowing → drying → inspection → discharging
Number of nozzles and the layout of the fluorescent sprays
Post time: Sep-13-2022