Non-destructive testing method of 316 stainless steel pipe welds

1. X-ray inspection
It can pass through substances that cannot be penetrated by light, and check whether there are pores in the welding head, unstable welding, cracks, slag inclusions, shrinkage holes, etc.; it can detect the plane position and size of the defect and can detect the defects at the defect. Plane position and size, etc. However, it is usually difficult to find defects in the pipeline. There are some small cracks on the welds, and factors such as the depth of the defects cannot be detected.

2. Ultrasound examination
Using the principle of ultrasonic detection, it will be reflected when encountering a certain interface. This system can detect raw materials and 316 stainless steel pipes, and can also find problems during the welding process. It can determine the location of the problem and the corresponding size parameters. It has extremely strong penetrability and can penetrate up to 10cm thick. However, problems existing in welds of coarse-grained materials cannot be detected. In addition, the location and shape of defects have a great impact on the detection results.

3. Magnetic particle inspection
The basic principle is that after the stainless steel pipe is magnetized if there are some internal problems, the distribution of the magnetic force will change to a certain extent. This method mainly detects problems with face openings or near faces in magnetic materials. However, this method often has difficulty detecting relatively complex stainless steel pipes.

4. Penetration testing
It uses the capillary phenomenon to allow the penetrant to enter the defects and then cleans the 316 stainless steel pipe to remove excess penetrant. Use the developer to absorb water and adsorb the penetrant in the defects, thereby discovering some minor problems in time.

For 316 stainless steel pipes, X-ray, ultrasonic, magnetic particle, permeability, and other inspection methods all use non-destructive testing methods. The quality inspection of this link is to detect flaws in the stainless steel pipes to ensure their normal and safe operation. The accuracy of the final inspection results depends entirely on whether the various operations during the inspection process are reasonable and complete. When purchasing 316 stainless steel pipes, you must pay special attention to the merchant's quality inspection management system, which directly determines the quality of the stainless steel pipes.