Flaw detection method uses

Each testing method can only detect certain defects in the material. Therefore, any kind of non-destructive testing techniques can not be detected in all pipe defects. For example, conventional eddy current testing method can only pass through the detection of the steel surface and near-surface and oriented generally transverse defects, flaws and defects of vertical pipe inside or inner surface of the powerless. Therefore, using a variety of non-destructive testing methods are combined to maximize the detection of all types of defects in the pipe, so as to ensure the quality of manufactured products, has become a very important part of the test pipe production.

Originally, through a combination of ultrasonic flaw detection method and eddy current testing method to detect longitudinal defects purposes can be effectively detected in most of the pipe defects, and thus should be the preferred combination of NDT techniques. However, due to limitations on the speed of the ultrasonic flaw detection method, not only adapt to the requirements of high-speed steel pipe line inspection, but also with eddy current testing can not match the speed, so this combination it is not yet widely used.

And ultrasonic flaw detection technology Similarly, magnetic flux leakage detection assay technology has both vertical and horizontal probing points. The test for the steel pipe to detect longitudinal defects for the purpose of magnetic flux leakage inspection and ultrasonic inspection method has substantially the same function, i.e., can be detected and its internal and external pipe surfaces substantially oriented in the longitudinal direction of the types of defects, except that the inner and the interior is not as high detection sensitivity ultrasonic testing only. Further, magnetic flux leakage inspection method detection sensor (probe) can be selected as desired detection speed and settings, and the rotational speed of the handpiece can also be adjusted so that it can match with the eddy-current flaw wears in speed, but also to adapt steel online testing of the production line speed requirements.

From the above analysis, the combination of the lateral pipe to detect defects as the main purpose of encircling and eddy current inspection method to detect defects as the main purpose of longitudinal magnetic flux leakage testing method can effectively detect defects in steel major, and adapt to the online test speed requirements. This combination of testing techniques for the vast majority of steel quality inspection standards and sufficient to meet the user's requirements, such as low-pressure boiler tube, fluid pipe, structural pipe, tubing and other oil wells. The quality requirements for higher-pressure boiler tubes, high-pressure chemical fertilizer pipes, etc., after the online test this combination of testing techniques, the relevant standards must also be subjected to ultrasonic flaw detection.