Effect of strain rate on low cycle fatigue with hold time in 9Cr rotor steel

One of the main mechanisms of turbine rotor damage is cyclic thermal stress produced during transition conditions, such as warm-up and shutdown processes. In this paper, the cyclic damage with ramp rate is studied in terms of material properties. To evaluate thermal stress damage during the cyclic o...

Full description

Saved in:
Bibliographic Details
Published in:Materials research innovations 2013-10, Vol.17 (5), p.332-336
Main Authors: Kim, K.-C., Ma, Y.-W., Kong, B.-O., Kim, M.-S., Kang, S.-T.
Format: Article
Language:English
Subjects:
9Cr steel
Chromium steels
Creep-fatigue interaction
Damage
Ductility exhaustion method
Hysteresis loops
Low cycle fatigue
Mathematical models
Plastic deformation simulation
Rotors
Steels
Strain rate
Thermal stresses
Time fraction method
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:One of the main mechanisms of turbine rotor damage is cyclic thermal stress produced during transition conditions, such as warm-up and shutdown processes. In this paper, the cyclic damage with ramp rate is studied in terms of material properties. To evaluate thermal stress damage during the cyclic operation, experiments were carried out on low cycle fatigue with hold time and a range of strain rates for COST FB2, 9Cr ferritic steel. Initially, the experimental fatigue life was evaluated using the time fraction and ductility exhaustion methods. The two analysis methods are compared with real life cases of different hold times and strain rates, and the accuracy is discussed. Next, to predict the plastic deformation curve for low cycle fatigue with hold time more accurately, an attempt was made to simulate cyclic hysteresis loop behaviour numerically using a time dependent viscoplastic constitutive model, and this was compared with the experimental hysteresis loop curve for each cycle number.
ISSN:1432-8917
1433-075X
DOI:10.1179/1432891713Z.000000000252