The Effect of Hold Time on Low Cycle Fatigue Behavior of 2 1/4Cr-1Mo Steel.

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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Hold time effects on low cycle fatigue behavior of HAYNES 230® superalloy at high temperatures

Materials Science and Engineering A ◽

10.1016/j.msea.2005.05.120 ◽

2005 ◽

Vol 409 (1-2) ◽

pp. 282-291 ◽

Cited By ~ 37

Author(s):

Y.L. Lu ◽

L.J. Chen ◽

G.Y. Wang ◽

M.L. Benson ◽

P.K. Liaw ◽

...

Keyword(s):

High Temperatures ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Hold Time ◽

Cycle Fatigue ◽

Time Effects ◽

Haynes 230

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

Materials Science and Engineering A ◽

10.1016/j.msea.2018.05.107 ◽

2018 ◽

Vol 730 ◽

pp. 197-206 ◽

Cited By ~ 7

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

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

Journal of Pressure Vessel Technology ◽

10.1115/1.4025080 ◽

2013 ◽

Vol 135 (6) ◽

Cited By ~ 17

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.

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Influence of Hold-Time and Temperature on the Low-Cycle Fatigue of Incoloy 800

Journal of Engineering for Industry ◽

10.1115/1.3428273 ◽

1972 ◽

Vol 94 (3) ◽

pp. 930-934 ◽

Cited By ~ 7

Author(s):

C. E. Jaske ◽

H. Mindlin ◽

J. S. Perrin

Keyword(s):

Fatigue Life ◽

Low Cycle Fatigue ◽

Fatigue Behavior ◽

Compressive Strain ◽

Hold Time ◽

Strain Range ◽

Cyclic Fatigue ◽

Cycle Fatigue ◽

Incoloy 800 ◽

Strain Cycling

A study has been conducted to determine the low-cycle fatigue behavior of solution-annealed Incoloy 800 bar at temperatures from 800–1400 deg F. The experimental work included evaluation of specimens under both continuous, completely reversed strain cycling and under strain cycling with hold time periods at the strain limits. At 1000, 1200, and 1400 deg F, it was found that 10-min hold-times at the tensile strain limit during every cycle significantly reduced the cyclic fatigue life compared to continuous cycling. However, there was little reduction in cyclic fatigue life when 10-min hold-times were introduced at the compressive strain limits or at both the tensile and compressive limits. The ratio of hold-time cyclic fatigue life to no-hold-time cyclic fatigue life decreased as the length of hold time increased (at constant total strain range) and as the magnitude of strain range decreased (at constant hold-time length).

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