Introduction
Magnetic flux leakage testing and ultrasonic testing are two different detection methods mainly used to detect defects or cracks in metal materials.
Details
Magnetic flux leakage testing and ultrasonic testing are two different detection methods mainly used to detect defects or cracks in metal materials. The differences between them are mainly reflected in the following aspects:
Detection principle
Thermal detection is the use of a sensing field to detect changes in the magnetic field and determine whether there are missing paths or cracks in the material. The presence of missing paths or cracks in the tested material can cause disturbances in the magnetic field, thereby affecting the magnitude and shape of the magnetic field signal. By analyzing the magnetic field signal, the type, size, and location of defects can be determined
Set relevant parameters.
Ultrasonic testing utilizes the propagation characteristics of sound waves to determine the presence of abnormalities in materials by detecting the sound wave signals in the material. Based on the characteristics such as the speed and energy of sound waves propagating in materials, defects or cracks in materials can be detected, located, and measured.
Detection object
Magnetic flux leakage testing is mainly applied to the detection of magnetic metal materials, such as steel, ferroalloys, etc. Because magnetic materials have magnetization under the action of a magnetic field, electromagnetic non-destructive testing can generate local magnetic field disturbances when defects or cracks exist, which facilitates the implementation of magnetic leakage testing. Ultrasonic testing is also commonly used to detect non-metallic materials such as ceramics and plastics, as well as various foam materials. Ultrasonic testing is suitable for the detection of various metal materials, regardless of their magnetic properties, and can perform accurate detection and measurement.
check the accuracy
The detection accuracy of magnetic flux leakage testing is relatively low, usually only able to determine parameters such as the approximate range and depth of defects. Magnetic flux leakage testing cannot accurately measure cracks in materials, let alone detect non-magnetic materials.
Relatively speaking, ultrasonic flaw detection has high detection accuracy, can measure smaller defects and finer cracks, provide clearer measurement data, and is suitable for the detection of various metal and non-metal materials.
Testing conditions
During the testing process, it is required that the magnetic field can fully penetrate the tested material, which means that surface treatment and control of the magnetic field direction need to be carried out on the tested material. Magnetic flux leakage testing has low requirements for environmental conditions and does not require special environmental control. It can detect materials on site. However, leak detection also requires special probes and testing equipment, usually in a laboratory or specialized testing site. Ultrasonic testing is sensitive to environmental conditions and requires a relatively clean environment to avoid interference from noise and noise. In summary, magnetic flux leakage testing and ultrasonic testing are commonly used non-destructive testing methods, each with unique advantages and applications. In practical applications, automatic flaw detection requires selecting corresponding detection methods based on specific detection requirements and material characteristics to achieve the best detection results.
