Non-destructive testing refers to the use of material internal structural abnormalities or defects caused by thermal, acoustic, optical, electrical, magnetic and other changes in the premise that does not damage or affect the performance of the tested object, does not harm the internal organization of the tested object, physical or chemical methods as a means to help modern technology and equipment. Method for inspecting and testing the structure, nature, condition and defect type, nature, quantity, shape, position, size, distribution and change of the specimen inside and on the surface. At the moment, The most commonly used non-destructive Testing is mainly five kinds: Ultrasonic Testing UT(Ultrasonic Testing), Radiographic testing RT(Radiographic Testing), Magnetic particle testing MT(Magnetic particle Testing), penetration testing Penetrant Testing (PT), Eddy current Testing (ET). This document mainly lists various test pieces or test blocks used in the process of magnetic particle testing, penetration testing and eddy current testing, so that users can have a more comprehensive understanding of this.
Penetrant detection of PT can detect surface defects of non-magnetic materials, thus providing a complementary means for magnetic particle detection. Penetration test method, that is, a liquid dye is used on the surface of the test material and retained on the body surface for a preset time, the dye can be a colored liquid that is recognizable under normal light, or a yellow/green fluorescent liquid that requires special light to appear. This liquid dye is a crack in the opening of the material surface due to "capillary work". Capillary action occurs throughout the stay of the dye until the excess dye is completely cleaned. At this time, a developer is applied to the surface of the material to be tested, penetrates into the crack and colors it, and then appears. The detection personnel with appropriate qualifications can analyze the display trace. Penetration testing can be widely used to detect the surface opening defects of most non-absorbent materials, such as steel, non-ferrous metals, ceramics and plastics, etc., and can also be comprehensively tested for complex defects at one time.
According to the requirements of JB/T6064-2015 and NB/T47013-2015 standards, our company has produced aluminum alloy A-type test blocks, three-point B-type test blocks, five-point B-type test blocks. The crack line of the test block is clear, the display is intuitive, and it can accurately test the ability of penetration detection agents and penetration detection technology to find small defects.
1, the test block should be thoroughly cleaned with acetone after use to remove the residual penetrant on the test block. After cleaning, the test block was soaked in a closed container filled with acetone or a mixture of acetone and anhydrous alcohol (volume mixing ratio of 1:1) for 30min, and then dried and stored, or stored by other effective methods.
2. Carry out the flaw detection procedure on the test piece according to the instruction manual of the flaw detection used. Because the color flaw detector can affect the fluorescence of the fluorescent flaw detector, the fluorescence and color flaw detector should be prepared separately.
Note: Do not knock the test block, so as not to cause the expansion of the defect, affecting the contrast and sensitivity of the detection.
The five-point B-type test block is made of S30408 stainless steel plate, single side chrome plated, 152mm×57mm area sandblasting, there are five radiating crack areas from large to small, the length and diameter difference of the crack zone is obvious, and the naked eye is not easy to see. It is mainly used to test the sensitivity of the penetration detection agent system and the correctness of the operation process.