Casing is a high-end product of steel pipe production. There are many types of shells. The diameter of casing varies from 15 kinds to specifications, and the outer diameter ranges from 114.3 mm to 508 mm. The steel grades are J55, K55, N80 and L-80. There are 11 kinds of P-110, C-90, C-95, T-95 and so on. There are many types and requirements for casing end-buckle, which can process button types of STC, LC, BC and VAM. The production and installation of tubing and casing involves many tests, including the following contents:


1. Ultrasound detection
When the ultrasonic wave propagates in the material to be measured, the changes of the acoustic characteristics and internal structure of the material have a certain influence on the propagation of the ultrasonic wave. The change of the degree and condition of the ultrasonic wave is to detect the changes of the properties and structure of the material.


2. Radiation detection
Radiation detection uses the difference of the amount of radiation transmitted through the normal part and the defect, which leads to the difference of blackness on the film.


3. Penetration test
The penetration test uses liquid capillary to penetrate the permeate into the open defects on the surface of solid materials, and then the permeate is sucked out to the surface by developer to show the existence of defects. The penetration test is suitable for all kinds of metal and ceramic workpieces. The time from penetration operation to defect display is relatively short, generally about half an hour. It can detect surface fatigue, stress corrosion and welding cracks, and can directly measure crack size.


4. Magnetic Particle Detection
Magnetic particle detection uses magnetic flux leakage at the defect to absorb magnetic particles and form magnetic traces to provide defect display. It can detect surface and subsurface defects, and it is easy to identify defect characteristics.  Coatings and electroplated surfaces do not affect detection sensitivity.


5. Eddy Current Detection
Eddy current detection mainly uses the eddy current induced by ferromagnetic coils in the workpiece to analyze the internal quality of the workpiece. It can detect surface and near surface defects of various conductive materials. Usually, parameter control is difficult, test results are difficult to interpret, and objects need to be detected. It must be a conductive crack and indirectly measure the length of the defect.


6. Magnetic flux leakage detection
Oil leakage detection of casing is based on high permeability of ferromagnetic materials. The quality of the shell in service is measured by measuring the permeability change caused by defects in ferromagnetic materials.


7. Magnetic Memory Detection
Magnetic memory testing originates from the relationship between the physical properties of metal magnetic phenomena and the miss distance. It has the advantages of high efficiency, low cost and no need of polishing. It has important and broad application prospects in industry.