Stainless Steel Industrial Welded Pipe Annealing And Non-Annealing Distinction
1. The pipe can be judged by the echo. Tap on each tube and listen for the echo at the mouth. If the echo is higher and sharper, it has been annealed. Because the internal crystal structure of annealed parts is more uniform and dense, it can produce higher pitch echo. And unannealed parts due to more tissue defects, can absorb part of the acoustic energy, so in the mouth of the lower tone, some stuffy. Sonar can be used if conditions permit.
2. Use a digital multimeter with better accuracy to measure the resistance of each tube per unit length (such as 2 meters). The resistance of stainless steel is large, it should be able to measure, the resistance of the annealed steel is smaller than that of the annealed steel. Dry everything before testing, no liquid.