What is the difference between x-ray flaw detection and ultrasonic flaw detection in nondestructive testing methods?

Date：2022-11-29 16:05:32 Views：1526

The outstanding feature of nondestructive testing is that it can be tested without damaging materials, workpieces and structures. Therefore, after nondestructive testing, the inspection rate of products can be very high. X-ray flaw detection and ultrasonic flaw detection are both nondestructive testing methods of nondestructive testing, and many people will ask what is the difference between x-ray flaw detection and ultrasonic flaw detection? In order to help you understand, the following contents are organized by the Core Creation Testing Network for your reference.

There is no difference from the perspective of inspection, but RT is preferred in the manufacturing process. RT can perform qualitative analysis on defects, which is more intuitive, while UT cannot be qualitative, and can only rate defects by comparing the size of defects with equivalent. Now there is a TOFT technology that can display the three-dimensional shape of defects, which is expected to be popular in the near future.

The detection mechanisms of the two methods are different, and each has its own characteristics: X-ray is sensitive to volumetric defects, but it is difficult to find linear defects, especially small incomplete penetration (insufficient fusion) or microcracks in thick plates, while ultrasonic is sensitive to linear defects, but it is difficult to determine the quantity of point defects; Radiography does not have high requirements on the surface of the workpiece. It evaluates the welding quality through the negative film. It is intuitive and easy to identify and archive, but difficult to determine the size of the depth direction. Ultrasonic exploration has strict requirements on the detection surface. It evaluates defects through the waveform on the fluorescent screen. It is easy to determine the depth, but not intuitive and difficult to archive. The characterization should be judged comprehensively, The inspectors shall have good quality and strong sense of responsibility.

Radiation is harmful to human body, so protection is required, and a large amount of film and drugs are consumed. The testing cost is high, while ultrasonic is harmless to human body, and the testing cost is low; Radiography can detect coarse grained materials (such as austenitic welds), while ultrasonic testing of such materials is difficult. a) Radiation: radiation to human body. With negative film, it is a strong point to detect defects beyond the standard such as pores and inclusions; b) Ultrasound: no radiation to human body. Without negative film, it is a strong point to detect defects beyond the standard such as cracks. X-ray can determine the position and size of defect plane projection, which is not applicable to the detection of forgings, pipes, bars, T-joints, corner joints and surfacing layers. Ultrasonic can determine the location and relative size of defects, which is applicable to the detection of forgings, pipes, bars, T-joints, corner joints and surfacing layers.

It mainly depends on the specific situation. It is not necessarily that RT is better than UT. If the wall thickness is very thick, it is difficult to evaluate small cracks due to the gray paste of the chip. However, UT can detect, each has its own advantages, and can also be said to complement each other. One is favorable for measuring vertical defects, and the other is favorable for measuring flat defects, depending on the situation. UT has relatively high requirements for the personal quality of flaw detection personnel, but at present, there are also recorded means of low UT cost. RT and UT are both widely used nondestructive testing methods. RT is more used to detect defects such as metal itself and welds, and RT costs more than UT.

Because the operating principle, physical basis and defect detection of the two methods are different, there is no comparability and no difference. The detection range of UT method is relatively wide, but due to the relationship between physical parameters such as wavelength and frequency, it also has its limitations. It has high detection rate for different tested pieces, especially for micro cracks, or defects in RT that tend to be in the same direction as the ray incidence. RT method is two-dimensional planar phase formation, which is relatively intuitive, but it is unable to determine the depth of defects and other parameters. At the same time, because of the influence of amplification distortion on curved surface inspection pieces such as pipes, quantitative errors are easy to occur. RT is very suitable for porosity, slag inclusion and other volumetric defects, while UT is suitable for crack with equal area.

The above is the relevant content of "X-ray flaw detection and ultrasonic flaw detection" brought by this core creation test. I hope it can help you, and we will bring more wonderful content later. The company's testing services cover: testing and verification of electronic components, IC authenticity identification, product design material selection, failure analysis, functional testing, factory incoming material inspection, tape weaving and other test items. Welcome to call Chuangxin Testing, we will serve you wholeheartedly.