How to check the welding process of laser welding fin tube?

 

1. Measure the delay time from the acoustic wave monitor to the receiving system and calculate the correction value of the delay time before laser welding the finned tube on site.

 

2. When measuring laser welded finned tubes, the transmitting and receiving probes shall rise and fall synchronously at the same elevation or maintain a fixed elevation difference.

 

3. The distance between measurement points of finned tube is 40cm, and when abnormality is found, it is densified to 20cm

 

4. To a certain extent, select the appropriate transmission voltage and amplifier gain, and keep them unchanged during the retest.

 

5. Laser welding finned tube can display and record the time history curve of received signal in real time to a certain extent.

 

6. The multiple laser welded finned tubes are fully combined with two as a detection section, and the detection is completed for multiple sections respectively.

 

7. After each group of laser welded finned tubes is tested, the test points shall be sampled at random for 10%, and the relative standard deviation of the delay time shall not be greater than 5%; The relative standard deviation of amplitude shall not be more than 10%