The detection methods of the surface defects of the square tube are mainly the following five:
1. Electric vortex detection
There are many forms of electric vortex flow detection. Commonly used are conventional vortex detection, far field vortex detection, multi -frequency vortex detection, and pulse vortex detection. Different types of signals. Its advantages are that the detection accuracy is high, the detection sensitivity is high, the detection speed is fast, and the surface and sub -surface of the tube to be detected can be detected. The disadvantage is that it is easy to determine the non -defect structure as a defect, the misunderstanding rate is high, and the detection resolution is not easy to adjust.
2. Ultrasonic detection
When an ultrasonic wave enters an object to encounter defects, part of the sound waves will produce reflexes. The transmission and receiver can analyze the reflex wave, which can accurately measure defects. Ultrasonic detection is often used for forging. The detection detection sensitivity is high, but it is not easy to check the complicated shape of the shape. It is required to be checked that the surface of the square tube has a certain degree of cleanliness, and the coupling agent is required to fill the gap between the probe and the surface of the inspection.
3. The principle of magnetic powder detection is to achieve magnetic fields in the square tube material. According to the interaction between the magnetic leakage field and the magnetic powder according to the defect, when the surface and the near surface are discontinuous or defect, Local distortion occurs magnetic poles. Its advantage is that there is less equipment investment, high reliability, and intuitive. The disadvantage is that the operating cost is high, the defects cannot be accurately classified, and the detection speed is low.
4. Infrared detection
Through high -frequency induction coils, inductive current generates the surface of the square tube, and the induction current will cause more electricity to consume more power in the defective area, causing local temperature to rise, and the local temperature is detected through infrared detection to determine the depth of defects. Infrared detection is generally used for defect detection of straight surface, which is not suitable for detecting surface uneven metals.
5. Magnetic detection
The leakage detection method and magnetic powder detection method of the square tube are very similar. The applicable range, sensitivity and reliability are stronger than the magnetic powder detection method.
