High-temperature low-cycle fatigue behavior of a 9Cr-ODS steel: Part 2 - hold time influence, microstructural evolution and damage characteristics

2018 ◽  
Vol 730 ◽  
pp. 197-206 ◽  
Author(s):  
Ankur Chauhan ◽  
Jan Hoffmann ◽  
Dimitri Litvinov ◽  
Jarir Aktaa
Keyword(s):  
High Temperature ◽  
Microstructural Evolution ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hold Time ◽  
Steel Part ◽  
Cycle Fatigue ◽  
Damage Characteristics ◽  
Ods Steel

High-temperature low-cycle fatigue behavior and microstructural evolution of an improved austenitic ODS steel

2018 ◽  
Vol 33 (12) ◽  
pp. 1814-1821 ◽  
Author(s):  
Ankur Chauhan ◽  
Dimitri Litvinov ◽  
Tim Gräning ◽  
Jarir Aktaa
Keyword(s):  
High Temperature ◽  
Microstructural Evolution ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Cycle Fatigue ◽  
Ods Steel ◽  
Image Position

Abstract

Low Cycle Fatigue and Creep-Fatigue Behavior of Alloy 617 at High Temperature

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Celine Cabet ◽  
Laura Carroll ◽  
Richard Wright
Keyword(s):  
High Temperature ◽  
Fatigue Testing ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Dominant Role ◽  
Hold Time ◽  
Outlet Temperature ◽  
Cycle Fatigue ◽  
Alloy 617 ◽  
Creep Fatigue

Alloy 617 is the leading candidate material for an intermediate heat exchanger (IHX) application of the very high temperature nuclear reactor (VHTR), expected to have an outlet temperature as high as 950 °C. Acceptance of Alloy 617 in Section III of the ASME Code for nuclear construction requires a detailed understanding of the creep-fatigue behavior. Initial creep-fatigue work on Alloy 617 suggests a more dominant role of environment with increasing temperature and/or hold times evidenced through changes in creep-fatigue crack growth mechanisms and failure life. Continuous cycle fatigue and creep-fatigue testing of Alloy 617 was conducted at 950 °C and 0.3% and 0.6% total strain in air to simulate damage modes expected in a VHTR application. Continuous cycle fatigue specimens exhibited transgranular cracking. Intergranular cracking was observed in the creep-fatigue specimens and the addition of a hold time at peak tensile strain degraded the cycle life. This suggests that creep-fatigue interaction occurs and that the environment may be partially responsible for accelerating failure.

Hold Time-Low Cycle Fatigue Behavior of Nickel Based Hastelloy X at Elevated Temperatures

2019 ◽  
Vol 20 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Donghyun Yoon ◽  
Inkang Heo ◽  
Jaehoon Kim ◽  
Sungyong Chang ◽  
Sungho Chang
Keyword(s):  
Elevated Temperatures ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hold Time ◽  
Cycle Fatigue ◽  
Hastelloy X

The Effect of Nitrogen Alloying on the Low Cycle Fatigue and Creep-Fatigue Interaction Behavior of 316LN Stainless Steel

2013 ◽  
Vol 794 ◽  
pp. 441-448 ◽  
Author(s):  
G.V. Prasad Reddy ◽  
R. Sandhya ◽  
M.D. Mathew ◽  
S. Sankaran
Keyword(s):  
Stainless Steel ◽  
Strain Rate ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hold Time ◽  
Cyclic Plasticity ◽  
Dynamic Strain ◽  
Cycle Fatigue ◽  
Intergranular Cracking ◽  
Creep Fatigue

Low cycle fatigue (LCF) and Creep-fatigue interaction (CFI) behavior of 316LN austenitic stainless steel alloyed with 0.07, 0.11, 0.14, .22 wt.% nitrogen is briefly discussed in this paper. The strain-life fatigue behavior of these steels is found to be dictated by not only cyclic plasticity but also by dynamic strain aging (DSA) and secondary cyclic hardening (SCH). The influence of the above phenomenon on cyclic stress response and fatigue life is evaluated in the present study. The above mentioned steels exhibited both single-and dual-slope strain-life fatigue behavior depending on the test temperatures. Concomitant dislocation substructural evolution has revealed transition in substructures from planar to cell structures justifying the change in slope. The beneficial effect of nitrogen on LCF life is observed to be maximum for 316LN with nitrogen in the range 0.11 - 0.14 wt.%, for the tests conducted over a range of temperatures (773-873 K) and at ±0.4 and 0.6 % strain amplitudes at a strain rate of 3*10-3 s-1. A decrease in the applied strain rate from 3*10-3 s-1 to 3*10-5 s-1 or increase in the test temperature from 773 to 873 K led to a peak in the LCF life at a nitrogen content of 0.07 wt.%. Similar results are obtained in CFI tests conducted with tensile hold periods of 13 and 30 minutes. Fractography studies of low strain rate and hold time tested specimens revealed extensive intergranular cracking.

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