Understanding the stress corrosion cracking growth mechanism of a cold worked alumina-forming austenitic steel in supercritical carbon dioxide

The crack growth behavior of a cold worked alumina-forming austenitic (AFA) steel in supercritical carbon dioxide (sCO(2)) and Ar is studied. AFA steel exhibits higher crack growth rates in sCO(2) than in Ar in the temperature range of 550 degrees C -650 degrees C. Creep cavities are widely observed near the crack growth paths and ahead of the crack tips on the specimens tested in both environments. Higher cavity density is observed at the crack tip of the specimen tested in sCO(2), which is caused by oxidation and carburization. The high cavity density weakens the grain boundaries and accelerates the fracture of the materials.

Automated summary

The crack growth behavior of a cold worked alumina-forming austenitic steel in supercritical carbon dioxide and argon was investigated. The study found that the crack growth rates in supercritical carbon dioxide were higher than in argon at temperatures ranging from 550°C to 650°C. Creep cavities were observed near the crack growth paths and ahead of the crack tips in both environments. Higher cavity density was observed in the specimen tested in supercritical carbon dioxide, which was caused by oxidation and carburization.