Quality inspection is an integral part of the seamless steel pipe production process. High-quality seamless steel pipes must go through a rigorous examination process. Here are the 5 most popular methods for quality inspection of seamless steel tubes.
- Ultrasonic testing
The non-destructive inspection method for the flaws in the seamless steel tubes is scrutinized by using the effect of the distinction in the acoustic properties of the seamless steel tubes and their internal defects on the propagation of the ultrasonic waves and the UT symbol represents it.
- Eddy Current Testing
The symbol ET represents a flaw detection method that uses the principle of electromagnetic induction to detect flaws on the surface and near surfaces of seamless steel tubes.
It is a more powerful tool for the rapid detection of bulk. Therefore, even not limited to large-caliber thermal expansion seamless steel tubes, it has become indispensable for all kinds of steel inspection. However, the automatic eddy current detection method is mainly applied to a point probe detection method for the quality inspection of a steel pipe and a method for detecting a probe through a probe.
The formerly discussed method uses point probes to detect the longitudinal defects of steel tubes at high speed. The detection speed is determined by the number of probes and the rotation speed. Generally, the detection speed is relatively slow. The latter detects the transverse defects of the steel tubes through the probe. This method is simpler and the detection speed is higher. Fast (usually up to 60m/min). In addition, due to the susceptible pair of through holes in the eddy current testing method, the primary process of the relevant standard is to replace the pipeline hydrostatic test.
- Magnetic Flux Leakage Testing
The surface of the seamless steel tube is magnetized, and the leakage in the magnetic field picks up the defect is picked with the electrical signal of the fault. LT symbolizes the non-destructive inspection method for finding the flaw.
- Magnetic Particle Inspection
It is a magnetic flux flaw detection method of non-destructive inspection using a phenomenon through which a leakage magnetic field of a ferromagnetic material is generated in a strong magnetic field and adsorbs magnetic powder. The symbol MT represents this measurement.
Magnetic flux leakage flaw detection is performed by applying a magnetic field to a seamless steel tube to make it magnetized (globally magnetized or partially magnetized). A magnetic flux escapes the surface of a seamless steel tube at the surface and near-surface defects of a seamless steel tube to form a leakage magnetic field. In the presence of the magnetic powder applied on the surface of the seamless steel pipe, an aggregated magnetic mark can be created, and the presence of defects can be exhibited. Magnetic particle detection methods are widely used to detect defects on the surface or near-surface of seamless steel tubes.
- Ray Detection
The symbol RT indicates a flaw detection method using rays to penetrate an object to detect defects inside the object.
The main application of ray detection is to detect the macroscopic or visible geometric defects (detection) inside the seamless steel tube. The radiography method is the most basic and most widely used ray detection method. Ray detection is suitable for most types of steel pipes. Radiographic inspection of the seamless structure of internal structure of the seamless steel pipe manufacturer and supplier can generate visual images, qualitative and quantitative accuracy, test results recorded directly, and long-term preservation. Ultrasonic detection and ray detection are mainly used to detect flaws inside seamless steel tubes. On the other hand, magnetic particle detection, penetration detection, and eddy current testing are used primarily to detect seamless steel tubes’ surface and near-surface defects.
Of course, to verify the mechanical properties of the seamless steel pipe meet the standard requirements, we should carefully prepare the test sample of the mechanical properties of the seamless steel pipe. Mechanical properties tests include tensile strength, yield strength, elongation, impact energy, etc. Crush test, flaring test, Hydrostatic test, Curl test, Cold bend test, and Perforation test are few necessary process performance tests. These tests are based on different standards and various uses of seamless steel tubes.
In short, in order to obtain high-quality seamless steel tubes, we must carry out rigorous testing of multiple methods and steps for each seamless steel tube.
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