What Specific Procedures Are There For Detecting Surface Flaws in Square Hollow Section?

We are all aware that surface flaws can occasionally be difficult to see without specialized testing tools. What specific procedures are there for detecting surface flaws in square hollow section?

For surface flaws in square hollow section, there are five primary methods of detection:

1. Eddy current testing

Eddy current testing can take many different forms; the most frequently utilized ones include conventional eddy current testing, far-field eddy current testing, multi-frequency eddy current testing, and pulsed eddy current testing. Different fault types and forms on the surface of the square hollow section will give different types of signals when metals are detected using eddy current sensors.

High detection sensitivity, high detection accuracy, and quick detection speed are its benefits. The drawbacks include a high rate of false positives, difficulty in adjusting the detection resolution, and ease with which non-defective structures can be mistaken for defects.

2. Ultrasonic examination

The ultrasonic wave will reflect in part when it encounters a fault inside the object. By analyzing the reflected wave, the transmitter and receiver can precisely identify the problem. Although ultrasonic testing has a high detection sensitivity and is frequently used for forging detection, it is challenging to scan pipes with complex geometry. A couplant is needed to fill the space between the probe and the inspected surface of the square hollow section under inspection since the surface must be relatively smooth.

3. Detection of magnetic particles

Realizing the magnetic field in the material's square hollow section is the basis for magnetic particle detection. When there are discontinuities or defects on the surface or near surface, the magnetic field lines will be locally distorted at the discontinuities or defects, according to the interaction between the leakage magnetic field at the defect and the magnetic powder. Making magnetic poles less equipment investment, high reliability, and intuitiveness are some of its benefits. The drawbacks include high operation costs, inaccurate classification of the defect, and sluggish detection rates.

4. Detection via infrared

An induced current is produced on the surface of the square hollow section using the high-frequency induction coil. The faulty area will utilize more energy as a result of the induced current, which will also raise the local temperature. Infrared rays measure the local temperature to ascertain the depth of the damage. It is not appropriate to utilize infrared detection to find defects on uneven surfaces; it is typically used to find flaws on flat surfaces.

5. Detection of magnetic flux leaks

The magnetic flux leakage detection method of the square hollow section is very similar to the magnetic particle detection method, but it has a wider application, greater sensitivity, and higher reliability.