Under what circumstances will stainless steel heat exchange tubes crack? After sampling and studying the cracked and intact parts of the stainless steel heat exchange tubes, and conducting macroscopic inspection, spectral analysis, mechanical property analysis, metallographic analysis, port morphology and energy spectrum analysis, the following conclusions were drawn:
The outer wall of the stainless steel heat exchange tube cracks in the area near the outer wall in an environment containing H+ and Cl-, and under the combined action of the expansion stress caused by the internal and external pressure difference, hydrogen-induced cracks occur in the outer wall.
During the crack expansion process, Cl-stress corrosion cracking plays a certain role in promoting cracks, and eventually rupture occurs.