Creep Failures

• Excessive deformation
1. Gas turbine blades
2. Lead on roofs
3. Suspension bridge cables
• Rupture
1. Trans-granular: deformation
2. Inter-granular: little / no deformation where longer lives; higher temperatures


• Pre-stressed concrete (eg, in fires)
1. Pre-stress eliminated
• Prolonged overheating
1. Just 50ºC above specification: 90% reduction in life
2. 11 years at 500ºC; one hour at 700ºC