Low cycle fatigue behaviour of T91 martensitic steel at 300°Cin air and in liquid lead bismuth eutectic

The low cycle fatigue behaviour of a 9Cr1MoNbV martensitic steel has been investigated at 350°C in air and in lead-bismuth eutectic (LBE). Total strain controlled tests were performed from Δεt = 0.40% to 1.2%. The material exhibited a pronounced cyclic softening in both environments. LBE reduced the fatigue resistance. LBE accelerated the formation of the long crack by promoting the growth of the first short cracks. A clear change in propagation mode was observed. In air, ductile fatigue striations were observed while in LBE a brittle fracture decorated by voluminous and largely spaced striations were visible. From EBSD analysis, it was concluded that in LBE, the long crack advanced quickly by repeated and discontinuous cleavage.

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Low-Cycle Fatigue Behaviour of Gas Turbine Alloys

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1974_188_037_02 ◽

1974 ◽

Vol 188 (1) ◽

pp. 321-328 ◽

Cited By ~ 1

Author(s):

W. J. Evans ◽

G. P. Tilly

Keyword(s):

Low Cycle Fatigue ◽

Fatigue Cracks ◽

High Stress ◽

Cyclic Creep ◽

Fatigue Curve ◽

Fatigue Behaviour ◽

Material Surface ◽

Tension Stress ◽

Cycle Fatigue ◽

Stress Tests

The low-cycle fatigue characteristics of an 11 per cent chromium steel, two nickel alloys and two titanium alloys have been studied in the range 20° to 500°C. For repeated-tension stress tests on all the materials, there was a sharp break in the stress-endurance curve between 103 and 104 cycles. The high stress failures were attributed to cyclic creep contributing to the development of internal cavities. At lower stresses, failures occurred through the growth of fatigue cracks initiated at the material surface. The whole fatigue curve could be represented by an expression developed from linear damage assumptions. Data for different temperatures and types of stress concentration were correlated by expressing stress as a fraction of the static strength. Repeated-tensile strain cycling data were represented on a stress-endurance diagram and it was shown that they correlated with push-pull stress cycles at high stresses and repeated-tension at low stresses. In general, the compressive phase tended to accentuate cyclic creep so that ductile failures occurred at proportionally lower stresses. Changes in frequency from 1 to 100 cycle/min were shown to have no significant effect on low-cycle fatigue behaviour.

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The slip character and low cycle fatigue behaviour: The influence of F.C.C. twinning and strain-induced F.C.C. → H.C.P. martensitic transformation

Acta Metallurgica ◽

10.1016/0001-6160(80)90042-5 ◽

1980 ◽

Vol 28 (1) ◽

pp. 75-88 ◽

Cited By ~ 44

Author(s):

G. Chalant ◽

L. Remy

Keyword(s):

Martensitic Transformation ◽

Low Cycle Fatigue ◽

Fatigue Behaviour ◽

Cycle Fatigue

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Low Cycle Fatigue Behaviour of Austenitic Stainless Steel at Cyrogenic Temperature

Tetsu-to-Hagane ◽

10.2355/tetsutohagane1955.68.3_471 ◽

1982 ◽

Vol 68 (3) ◽

pp. 471-476 ◽

Cited By ~ 6

Author(s):

Toshinori NAKAMURA ◽

Masatake TOMINAGA ◽

Hirokazu MURASE ◽

Yukio NISHIYAMA

Keyword(s):

Stainless Steel ◽

Austenitic Stainless Steel ◽

Low Cycle Fatigue ◽

Fatigue Behaviour ◽

Cycle Fatigue

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Low-cycle fatigue behaviour of laser welded high-strength steel DOMEX 700 MC

MATEC Web of Conferences ◽

10.1051/matecconf/201815705013 ◽

2018 ◽

Vol 157 ◽

pp. 05013 ◽

Cited By ~ 2

Author(s):

Peter Kopas ◽

Milan Sága ◽

František Nový ◽

Bohuš Leitner

Keyword(s):

Fatigue Life ◽

Welded Joints ◽

High Strength Steel ◽

Fatigue Testing ◽

Low Cycle Fatigue ◽

High Strength ◽

Fatigue Behaviour ◽

Total Strain Amplitude ◽

Cycle Fatigue ◽

Fatigue Life Analysis

The article presents the results of research on low cycle fatigue strength of laser welded joints vs. non-welded material of high-strength steel DOMEX 700 MC. The tests were performed under load controlled using the total strain amplitude ɛac. The operating principle of the special electro-mechanic fatigue testing equipment with a suitable clamping system was working on 35 Hz frequency. Fatigue life analysis was conducted based on the Manson-Coffin-Basquin equation, which made it possible to determine fatigue parameters. Studies have shown differences in the fatigue life of original specimens and laser welded joints analysed, where laser welded joints showed lower fatigue resistance. In this article a numerical analysis of stresses generated in bending fatigue specimens has been performed employing the commercially available FEM-program ADINA.

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