| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 860526 | Procedia Engineering | 2013 | 7 Pages |
Creep tests on both plain and notched specimens having ratio of notch throat radius to notch root radius ranging from 1 to 20 keeping the specimen diameter to notch throat diameter ratio fixed at 1.67. The creep rupture life of the material was found to increase in presence of notch at all the applied stresses. The extent of increase in rupture life was more at higher applied stresses. Creep rupture life was found to increase with notch acuity and tend to saturate at larger notch acuity. SEM fractography investigation revealed the presence of both plasticity induced dimpled intragranular ductile failure and creep cavitation induced intergranular brittle failure. The relative proportion of plasticity induced ductile failure to creep cavitation induced brittle failure decreased with increase in notch acuity and decrease in applied stress. Finite element analysis was carried out to study the effect of notch acuity on the stress distribution across the notch during creep exposure and its effect on creep rupture life. The variation of stresses at the skeletal point with notch acuity was used to characterize the state of stress in the notched specimen. The reduction in von-Mises stress with notch acuity at the skeletal point has been considered for the increase in rupture life of the relatively ductile 2.25Cr-1Mo steel.
