Tensile Creep Properties of Cr-Si Alloys at 980 °C in Air—Influence of Ge and Mo Addition

The tensile creep behavior of Cr-Si alloys with Cr ≥ 91 at.% was investigated in air at 980 °C with a constant load of 50–100 MPa. Additionally, the influence of substitutional alloying additions of 2 at.% Ge and Mo, leading to ternary alloys was studied. The addition of Ge or Mo results in an improvement in creep strength, with the highest strength achieved with addition of Mo. For longer creep exposure times a strong effect is observed, because of severe nitrogen uptake from the air, depending on alloy composition. Based on the results a novel mechanism for the impact of chromium nitride formation on the creep behavior is proposed.

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Improved tensile creep properties of yttrium- and lanthanum-doped alumina: a solid solution effect

Journal of Materials Research ◽

10.1557/jmr.2001.0064 ◽

2001 ◽

Vol 16 (2) ◽

pp. 425-429 ◽

Cited By ~ 24

Author(s):

Junghyun Cho ◽

Chong Min Wang ◽

Helen M. Chan ◽

J. M. Rickman ◽

Martin P. Harmer

Keyword(s):

Solid Solution ◽

Steady State ◽

Creep Behavior ◽

Solubility Limit ◽

Steady State Creep ◽

Tensile Creep ◽

Creep Properties ◽

Uniform Microstructure ◽

Equiaxed Grains ◽

Rare Earth Doped

The tensile creep behavior of yttrium- and lanthanum-doped alumina (at dopant levels below the solubility limit) was examined. Both compositions (100 ppm yttrium, 100 ppm lanthanum) exhibited a uniform microstructure consisting of fine, equiaxed grains. The creep resistance of both doped aluminas was enhanced, compared with undoped alumina, by about two orders of magnitude, which was almost the same degree of improvement as for materials with higher dopant levels (in excess of the solubility limit). In addition, measured creep rupture curves exhibited predominantly steady-state creep behavior. Our results, therefore, verified that the creep improvement in these rare-earth doped aluminas was primarily a solid-solution effect.

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A Physically Consistent Method for the Prediction of Creep Behavior of Metals

Journal of Applied Mechanics ◽

10.1115/1.3424657 ◽

1979 ◽

Vol 46 (4) ◽

pp. 800-804 ◽

Cited By ~ 13

Author(s):

G. J. Weng

Keyword(s):

Single Crystals ◽

Creep Behavior ◽

Pure Shear ◽

Tensile Creep ◽

Polycrystalline Materials ◽

Steady Creep ◽

Creep Properties ◽

Consistent Method ◽

Latent Hardening ◽

Good Agreement

A physically consistent method, which considers the deformation mechanisms, the active and latent hardening in single crystals, and their transient and steady creep, is proposed to predict the creep behavior of polycrystalline materials. This method consists of two steps: first, the material constants of single crystals are determined from the tensile creep data of the polycrystal, and then these constants are used to predict the creep properties of the same polycrystal under required loading conditions. This method simultaneously satisfies the requirements of equilibrium and compatibility over the grain boundaries, and is self-consistent. The proposed method was applied to calculate the creep strains of a 2618-T61 Aluminum alloy under pure shear, combined stress and nonradial loading; the results obtained were in good agreement with the test data.

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Stress Relaxation Testing For Analysis of 12Cr1MoVG Steel for Creep Strength Evaluation

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.353-358.408 ◽

2007 ◽

Vol 353-358 ◽

pp. 408-411 ◽

Cited By ~ 1

Author(s):

Wei Ming Sun ◽

Bing Bing Chen ◽

Wei Ya Jin ◽

Zeng Liang Gao

Keyword(s):

Elevated Temperature ◽

Stress Relaxation ◽

Constant Load ◽

Tensile Creep ◽

Stress Relaxation Test ◽

New Approach ◽

Creep Properties ◽

Time Stress ◽

Creep Analysis ◽

Short Time

The design of pressurized components at elevated temperature is limited by available mechanical properties that often do not span appropriate range of stress, time, strain and temperature. To improve the design process, a new approach based on short-time stress relaxation test (SRT) is introduced in steel tensile creep analysis. The experiments are implemented using SRT and tested for creep properties of 12Cr1MoVG steel at 560 °C. The results of creep curves agree well with the traditional constant load creep test data. The possibility to apply SRT approach is shown promising in the design of the pressurized component at elevated temperature.

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The Effect of Molybdenum on the Creep Behavior of Orthorhombic Titanium Aluminides

Volume 3: Turbo Expo 2002, Parts A and B ◽

10.1115/gt2002-30660 ◽

2002 ◽

Author(s):

Dominique A. Shepherd ◽

Vijay K. Vasudevan

Keyword(s):

Creep Behavior ◽

Titanium Aluminide ◽

Creep Resistance ◽

Titanium Aluminides ◽

Tensile Creep ◽

Atomic Fraction ◽

Beta Transus ◽

Creep Properties ◽

Orthorhombic Titanium ◽

Transus Temperature

The effect of molybdenum additions on the creep properties of two orthorhombic titanium aluminide materials, Ti-22Al-26Nb and Ti-22Al-24.5Nb-1.5Mo (% atomic fraction), has been investigated. Heat treatments below the beta transus temperature followed by a 16-hour ageing treatment produced similar microstructures. Using the similar microstructures (consisting of O laths in a B2 matrix with α2 dispersed at B2 grain boundaries) for the two compositions, tensile creep testing was conducted under stresses of 68 MPa, 160 MPa, and 197 MPa at temperatures of 590 °C and 760 °C. The creep results demonstrated the favorable effects of Mo on creep resistance in these orthorhombic titanium aluminides. Due to similar microstructures, results also suggested that improvements have been substructural, rather than purely microstructural, in nature.

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The Microstructure and Creep Behavior of a Boron-Modified Ti-15Al-33Nb (at%) Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.15-17.976 ◽

2006 ◽

Vol 15-17 ◽

pp. 976-981 ◽

Cited By ~ 4

Author(s):

C.J. Cowen ◽

Carl J. Boehlert

Keyword(s):

Creep Behavior ◽

Creep Resistance ◽

Constant Load ◽

Tensile Creep ◽

Stress Range ◽

Monolithic Alloy ◽

Temperature Range ◽

Normal Constituent

The affect of boron (B) on the microstructure and creep behavior of a Ti-15Al-33Nb (at%) alloy was investigated. In addition to the normal constituent phases present in the monolithic alloy, the B-modified alloy contained borides enriched in titanium and niobium. These borides were present in the form of needles/laths up to 50 μm long and 10 μm wide which took up 5-9% of the volume. Constant load, tensile-creep experiments were performed in the stress range of 150-340 MPa and the temperature range of 650-710°C, in both air and vacuum environments. An addition of 0.5 at% B did not improve the creep resistance of the monolithic alloy, while the addition of 5 at% B significantly improved the creep resistance.

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Structure Dependence of Tensile Creep Behavior in Thermo-Mechanically-Treated Ti-50Mol%Al Intermetallics

MRS Proceedings ◽

10.1557/proc-213-721 ◽

1990 ◽

Vol 213 ◽

Cited By ~ 3

Author(s):

Tohru Takahashi ◽

Hiroshi Oikawa

Keyword(s):

Creep Behavior ◽

Tensile Creep ◽

Ingot Metallurgy ◽

Structural Effects ◽

Creep Life ◽

Cast Material ◽

Creep Properties ◽

Structure Dependence ◽

Creep Characteristics

ABSTRACTTensile creep properties have been studied in Ti-50mol%Al intermetallics prepared by ingot metallurgy. Four types of structure were obtained in as-cast material (C), homogenized material (CA), isothermally forged material (F) and forged-and-recrystallized material (FA). Structural effects was investigated by comparing creep properties such as minimum creep rates, fracture strains and creep life among C, CA, F, and FA materials. Creep characteristics were strongly dependent upon the structure.

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Short-Term Creep-Rupture Behaviour of AISI 310S Austenitic Stainless Steel Sheets Manufactured in Salem Steel Plant, a Special Steels Unit of Steel Authority of India Limited, Ministry of Steel, Government of India

YMER Digital ◽

10.37896/ymer20.12/33 ◽

2021 ◽

Vol 20 (12) ◽

pp. 363-373

Author(s):

A Kanni Raj ◽

Keyword(s):

Stainless Steel ◽

Grain Boundary ◽

Creep Behavior ◽

Rupture Life ◽

Stress Rupture ◽

Constant Load ◽

Creep Rupture ◽

Steel Plant ◽

Tensile Creep ◽

Metallographic Examination

The creep behavior of AISI 310S stainless steel taken from SAIL’s Salem stainless steel plant has been investigated by constant load tensile creep test at the temperatures of 973, 1023, and 1073 K and loads of 66.6, 74.8, 86.6, and 94.8 MPa. It exhibits steadystate creep behavior in most test conditions. The double logarithm plot of rupture life and applied stress yielded straight lines at all the three test temperatures indicating that power-law creep due to dislocation climb is the operating mechanism of creep deformation. Linear relationship was obtained for plots of logarithm of rupture life against inverse temperature obeying Arrhenius type of temperature dependence with activation energy of 340 kJ/mol. The stress-rupture data yielded a master curve of Larson-Miller parameter. The plot of Monkman-Grant relationship is typical indicating that rupture is controlled by growth of grain boundary cavities. The metallographic examination of crept samples revealed formation of grain boundary voids and cracks leading to intergranular creep fracture. Deformation twins and carbide precipitates were also observed. Creep-rupture properties are compared with that of AISI 600 ironbased superalloy to analyze quantitatively its behavior

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Effect of Low-Temperature Annealing on Creep Properties of AlSi10Mg Alloy Produced by Additive Manufacturing: Experiments and Modeling

Metals ◽

10.3390/met11020179 ◽

2021 ◽

Vol 11 (2) ◽

pp. 179

Author(s):

Chiara Paoletti ◽

Emanuela Cerri ◽

Emanuele Ghio ◽

Eleonora Santecchia ◽

Marcello Cabibbo ◽

...

Keyword(s):

Creep Rate ◽

Applied Stress ◽

Minimum Creep Rate ◽

Annealing Treatment ◽

Constant Load ◽

Experimental Conditions ◽

Creep Properties ◽

Low Temperature Annealing ◽

Physically Based ◽

Excellent Description

The effects of postprocessing annealing at 225 °C for 2 h on the creep properties of AlSi10Mg alloy were investigated through constant load experiments carried out at 150 °C, 175 °C and 225 °C. In the range of the experimental conditions here considered, the annealing treatment resulted in an increase in minimum creep rate for a given stress. The reduction in creep strength was higher at the lowest temperature, while the effect progressively vanished as temperature increased and/or applied stress decreased. The minimum creep rate dependence on applied stress was modeled using a physically-based model which took into account the ripening of Si particles at high temperature and which had been previously applied to the as-deposited alloy. The model was successfully validated, since it gave an excellent description of the experimental data.

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