Study on microstructure and fatigue crack propagation of roll sleeves in an aluminum strip casting machine

Cracking is the main form of failure in the twin-roll continuous caster. The effects of microstructure on the fatigue crack propagation of caster roll sleeves was discussed by a failure analysis of scrap roll sleeves. The results show that surface thermal fatigue cracks where crack initiated lead to unstable propagation. Cracking failure was found to be generated transiently. The presence of bainite in tempered martensite resulted in a significantly decrease of fatigue crack propagation resistance in roll sleeves.