How to distinguish between annealed and non-annealed stainless steel welded pipe? The pipeline can be judged by echo. Click on each pipe and listen to the echo at the nozzle. If the echo is higher, then is sharper and has been annealed. Because the internal crystal structure of the annealed part is more uniform and dense, it can generate echoes at higher pitches. The resistance of the annealed steel is less than the resistance without annealing.

How to distinguish between annealed and non-annealed stainless steel welded pipe?

1 The tube can be judged by echo.

Click on each tube and listen for the echo at the nozzle. If the echo is higher, then is sharper and has been annealed. Because the internal crystal structure of the annealed portion is more uniform and dense, higher pitch echoes can be generated without annealing. Due to a large number of tissue defects, it can absorb part of the acoustic energy, so the tone at the nozzle is very low and very boring. If there are conditions, it can be detected by sonar.

2 Use a higher precision digital multimeter to measure the resistance per unit length (for example, 2 meters). The resistance of stainless steel should be measurable. The resistance of the annealed steel is less than the resistance without annealing. Dry before the test without liquid. These methods can distinguish between annealed and non-annealed stainless steel welded tubes.