The use of steel flanges in industrial structural parts is mainly to improve the connection and keep the pipelines sealed without leakage. However, many steel flanges will corrode and age after being used for some time, thus losing their tightness. Therefore, it is very necessary to conduct anti-corrosion tests on steel flanges regularly. Here to share with you the process of measuring the corrosion of steel flanges.
First of all, it must be affirmed that the steel flange should be maintained and inspected regularly. After corrosion occurs, it usually shows that the pipe wall of the steel flange becomes thinner, and local pits and pits appear. The reasons and methods for the internal corrosion of stainless steel flanges need to be carried out according to certain methods and principles. The corrosion detection methods of steel flanges that can be widely used at home and abroad are the magnetic flux leakage method and ultrasonic detection method.
Ultrasonic method Ultrasonic detection method is to use the principle of ultrasonic pulse reflection to measure the thickness of the pipe wall after corrosion. Leakage flux method The basic principle of leakage flux method detection is based on the high magnetic permeability of ferromagnetic materials. The magnetic permeability at the corrosion defect of the steel flange is much smaller than that of the steel flange. , the steel flange is magnetized under the action of an external magnetic field. When there is no defect in the steel flange, most of the magnetic force lines pass through the steel pipe. At this time, the magnetic force lines are evenly distributed; when there are defects inside the steel flange, the magnetic force lines bend. And a part of the magnetic flux leaks out of the surface of the steel pipe. The existence of defects can be judged by detecting the leakage flux escaping from the surface of the magnetized steel flange.
In addition, when testing, the probe is used to transmit ultrasonic pulses vertically to the inner wall of the steel flange. The probe first receives the reflected pulse from the inner surface of the pipe wall, and then the ultrasonic probe will receive the reflected pulse from the outer surface of the pipe wall. This pulse is consistent with the inner surface. The distance traveled between reflected pulses reflects the thickness of the tube wall. In the actual detection, the elbow needs to be carried out according to the actual situation and instructions and can be inspected according to the ultrasonic method.
The ultrasonic testing method is also applicable to the thickness measurement and metal performance measurement of other metal structural parts.
Post time: Apr-10-2023