Cause of Cracking on Rocket Engine Shell

The rocket engine shell cracked during the static test. The causes of cracking on shell were analyzed by means of chemical composition analysis, mechanical property test, metallographic examination and fracture analysis. The results show that the composition segregation caused the micro defects in the spinning process. In the process of hydrostatic test, the active ions in water accelerated the crack propagation, which resulted in hydrogen embrittlement and stress corrosion cracking of shell in static test.