scholarly journals Creep rupture properties of bare and coated polycrystalline nickel-based superalloy Rene®80

2021 ◽  
pp. 36-36
Author(s):  
M.M. Barjesteh ◽  
S.M. Abbasi ◽  
K.Z. Madar ◽  
K. Shirvani
Keyword(s):  
Elevated Temperatures ◽  
Life Time ◽  
Creep Rupture ◽  
Polycrystalline Nickel ◽  
Creep Life ◽  
Nickel Based Superalloy ◽  
Platinum Aluminide ◽  
Rupture Properties ◽  
Low Activity ◽  
Rupture Behavior

Creep deformation is one of the life time limiting reasons for gas turbine parts that are subjected to stresses at elevated temperatures. In this study, creep rupture behavior of uncoated and platinum-aluminide coated Rene?80 has been determined at 760?C/657 MPa, 871?C/343 MPa and 982?C/190 Mpa in air. For this purpose, an initial layer of platinum with a thickness of 6?m was applied on the creep specimens. Subsequently, the aluminizing were formed in the conventional pack cementation method via the Low Temperature-High Activity (LTHA) and High Temperature-Low Activity (HTLA) processes. Results of creep-rupture tests showed a decrease in resistance to creep rupture of coated specimen, compared to the uncoated ones. The reductions in rupture lives in LTHA and HTLA methods at 760?C/657 MPa, 871?C/343 MPa and 982?C/190 MPa were almost (26% and 41.8%), (27.6% and 38.5%) and (22.4% and 40.3%), respectively as compared to the uncoated ones. However, the HTLA aluminizing method showed an intense reduction in creep life. Results of fractographic studies on coated and uncoated specimens indicated a combination of ductile and brittle failure mechanisms for all samples. Although, the base failure mode in substrate was grain boundary voids, cracks initiated from coating at 760?C/657MPa and 871?C/343. No cracking in the coating was observed at 982?C/190MPa.

Survey of Various Special Tests Used to Determine Elastic, Plastic, and Rupture Properties of Metals at Elevated Temperatures

1960 ◽  
Vol 82 (4) ◽  
pp. 867-880 ◽  
Author(s):  
F. Garofalo
Keyword(s):  
Elastic Moduli ◽  
Elevated Temperatures ◽  
Metals And Alloys ◽  
Solid State Reactions ◽  
Hardness Tester ◽  
Rupture Properties ◽  
The Relationship ◽  
Temperature Time ◽  
Rupture Behavior ◽  
Hot Hardness

Testing techniques employed in determining the elastic moduli, that is, Young’s modulus, shear modulus, and Poisson’s ratio, at room and elevated temperatures are described. These techniques depend on static or dynamic measurements. A comparison and an analysis of test results determined by these two methods are presented. The effect of composition, grain size, and various transformations on the elastic moduli or their temperature dependence is discussed. A review of techniques and experimental data on the effect of high strain rates on plastic and rupture behavior of metals, and alloys at elevated temperatures is presented. It is shown that recovery effects explain qualitatively the results obtained. A brief description of the various stages of recovery is also presented. The variation of hardness with temperature is discussed for pure metals and alloys, including a description of a typical hot-hardness tester. The relationship between hardness and tensile strength, creep, and creep-rupture behavior is briefly summarised. The use of the hot-hardness tester as a research tool for following solid-state reactions at elevated temperatures is discussed. These reactions may depend on temperature, time, or plastic strain or a combination of these.

Creep Rupture Behavior of Selected Turbine Materials in Air, Ultra-High Purity Helium, and Simulated Closed Cycle Brayton Helium Working Fluids

1981 ◽  
Vol 103 (2) ◽  
pp. 331-337 ◽  
Author(s):  
R. L. Ammon ◽  
L. R. Eisenstatt ◽  
G. O. Yatsko
Keyword(s):  
High Purity ◽  
Creep Rupture ◽  
Working Fluid ◽  
Closed Cycle ◽  
Working Fluids ◽  
Ultra High Purity ◽  
Rupture Properties ◽  
Rupture Behavior

Five turbine materials, IN100, 713LC, MAR-M-509, MA-754 and TZM were selected as candidate materials for use in a Compact Closed Cycle Brayton System (CCCBS) study in which helium served as the working fluid. The suitability of the alloys to serve in the CCCBS environment at 927 C (1700 F) was evaluated on the basis of creep-rupture tests conducted in air, ultra-high purity helium (>99.9999 percent), and a controlled impurity helium environment. Baseline reference creep rupture properties for times up to 10,000 hr were established in a static ultra-high purity helium environment.

Capped End, Thin-Wall Tube Creep-Rupture Behavior for Type 316 Stainless Steel

1963 ◽  
Vol 85 (1) ◽  
pp. 71-86 ◽  
Author(s):  
G. H. Rowe ◽  
J. R. Stewart ◽  
K. N. Burgess
Keyword(s):  
Biaxial Tension ◽  
Rupture Life ◽  
Creep Rupture ◽  
Uniaxial Tensile ◽  
Thin Wall ◽  
Rupture Ductility ◽  
Statistical Argument ◽  
Stress Ratios ◽  
Rupture Properties ◽  
Rupture Behavior

The creep-rupture behavior of 34 capped end, thin-wall tubular specimens was correlated with results for 54 uniaxial tensile specimens in tests at 1350 F, 1500 F, and 1650 F. Basic tests established isotropy in creep-rupture properties as well as metallurgical stability for the material used in the study. Significant correlations of creep rate, rupture life, and rupture ductility were established for the cases of stress ratios 1/0 and 2/1 in the biaxial tension quadrant. Data from tests at 1500 F were evaluated for a statistical argument. This same material was subsequently utilized in a high temperature structures research program to be reported separately.

Enhanced Creep Life Evaluations for Grade 91 Circumferential Weldments

2017 ◽  
Author(s):  
Marvin J. Cohn
Keyword(s):  
Applied Stress ◽  
Hoop Stress ◽  
Axial Stress ◽  
Creep Damage ◽  
Creep Rupture ◽  
Piping System ◽  
Remaining Life ◽  
Creep Life ◽  
Rupture Properties ◽  
Applied Stresses

The basic power piping creep life calculations consider the important variables of time, temperature and stress for the creep rupture properties of the unique material. Some engineering evaluations of remaining life estimate the applied stress as the design stress obtained from a conventional piping stress analysis. Other remaining life evaluations may assume that a conservative estimate of the applied stress is no greater than the hoop stress due to pressure. The creep rupture properties of the unique material are usually obtained from the base material creep rupture properties. The typical methodologies to estimate remaining life do not consider the actual applied stress due to malfunctioning supports, multiaxial stress effects, axial and through-wall creep redistribution, time-dependent material-specific weldment creep rupture properties, residual welding stresses, and actual operating temperatures and pressures. It has been determined that the initiation and propagation of Grade 91 creep damage is a function of stress to about the power of 9 at higher applied stresses. There have been many examples of malfunctioning piping supports creating unintended high stresses. When the axial stress is nearly as high as the hoop stress, the applicable corresponding uniaxial stress for creep rupture life is increased about 30%. Multiaxial stress effects in circumferential weldments (e.g., when the axial stress is nearly as high as the hoop stress) can reduce the weldment creep life to less than 1/6th of the predicted life assuming a uniaxial stress or hoop stress due to pressure only. Since 2012, the ASME B31.1 Code has required that significant piping displacement variations from the expected design displacements shall be considered to assess the piping system’s integrity [1]. This paper discusses a strategy for an enhanced creep life evaluation of power piping circumferential weldments. Piping stresses can vary by a factor greater than 2.0. Consequently, the range of circumferential weldment creep rupture lives for a single piping system may vary by a factor as high as 40. Although there is uncertainty in the operating times at temperatures and pressures, all of the weldments within the piping system have the same time, temperatures, and pressures, so the corresponding uncertainties for these three attributes are normalized within the same piping system. Since the applied stresses are the most important weld-to-weld variable within a piping system, it is necessary to have an accurate evaluation of the applied stresses to properly rank the creep rupture lives of the circumferential weldments. This methodology has been successfully used to select the lead-the-fleet creep damage in circumferential weldments over the past 15 years.

Creep Rupture of MoSi2/SiCp Composites

1993 ◽  
Vol 322 ◽  
Author(s):  
Jonathan D. French ◽  
Sheldon M. Wiederhorn ◽  
John J. Petrovic
Keyword(s):  
Creep Rupture ◽  
Tertiary Creep ◽  
Volume Percent ◽  
Creep Life ◽  
Particle Content ◽  
Creep Ductility ◽  
Sic Particles ◽  
Creep Curves ◽  
Rupture Behavior ◽  
Sic Particle

AbstractWe studied the creep rupture of a series of MoSi2 materials reinforced with SiC particles. Particulate contents were in the range of 0 to 40 volume percent. Temperature and stress ranges were 1050°C to 1200°C and 10 MPa to 50 MPa, which gave failures ranging from 1 hour to 1500 hours. The creep curves show an extensive tertiary regime, accounting for 25-95% of the total lifetime. Tertiary creep increases with increasing stress and temperature. Cavitation occurs throughout the creep life, and tertiary creep is associated with the linkage of cavities into large cracks. The creep life improves with increasing SiC particle content, with a concurrent loss of creep ductility. Significant improvement occurs only when the particle content is greater than 30 volume percent. Our studies suggest that the creep and creep rupture behavior of MoSi2 can be further improved by increasing the content of SiC particles.

Stress Redistribution and Rupture Due to Creep in a Uniformly Stretched Thin Plate Containing a Circular Hole

1973 ◽  
Vol 40 (1) ◽  
pp. 244-250 ◽  
Author(s):  
D. R. Hayhurst
Keyword(s):  
Elevated Temperatures ◽  
Numerical Procedure ◽  
Prediction Method ◽  
Creep Rupture ◽  
Constitutive Relationship ◽  
High Temperature Creep ◽  
Uniaxial Creep ◽  
Aluminum Plates ◽  
Single Stress ◽  
Rupture Behavior

A uniaxial theory of low-stress, high-temperature creep rupture has been shown to predict the results of uniaxial creep rupture tests. By including the creep rupture relationships into the accepted multiaxial deformation laws and following the numerical procedure outlined in a previous publication, a lower bound on the rupture time has been obtained for the case of a biaxially loaded plate containing a small hole at its center. It has been shown that the rupture behavior of the structure is controlled by a single stress whose magnitude is independent of the form of the constitutive relationship. The results of the prediction method agreed well with the experimentally determined values for aluminum plates tested at elevated temperatures.

scholarly journals Strength of Materials at Elevated Temperatures. Long Term Creep-Rupture Properties and Microstructure of Weld Metal on 2.25Cr-1Mo Steel Thick Plate.

1999 ◽  
Vol 48 (2) ◽  
pp. 122-129 ◽  
Author(s):  
Takashi WATANABE ◽  
Masayoshi YAMAZAKI ◽  
Hiromichi HONGO ◽  
Junichi KINUGAWA ◽  
Tatsuhiko TANABE ◽  
...  
Keyword(s):  
Weld Metal ◽  
Thick Plate ◽  
Elevated Temperatures ◽  
Creep Rupture ◽  
Strength Of Materials ◽  
Term Creep ◽  
Rupture Properties

Creep Life Evaluations of ASME B31.1 Allowance for Variation From Normal Operations: 11 Materials

2019 ◽  
Author(s):  
Marvin J. Cohn ◽  
Ron Haupt
Keyword(s):  
Base Metal ◽  
Rupture Life ◽  
Creep Damage ◽  
Creep Rupture ◽  
Creep Life ◽  
Material Creep ◽  
Metal Creep ◽  
Life Consumption ◽  
Rupture Properties ◽  
Design Pressure

Abstract The ASME B31.1-2018 Power Piping Code (Code) paras. 102.2.4, 102.3.3, and 104.8.2 provide an allowance regarding operating above the design temperature and design pressure for short time periods. The concept of allowing occasional operation for short periods of time at higher than the design pressure or design temperature has been in the Code since 1967. These 1967 Code para. 102.2.4 limitations were based on engineering judgment that can now be quantitatively evaluated for the additional creep life consumption (creep rupture damage accumulation). This study primarily is a quantitative estimate of the permitted increased life consumption, considering minimum creep rupture properties, associated with the 2018 Code operating allowances for piping materials operating in the creep range. Eleven base metal materials are considered in this paper — low carbon steel, 1.25Cr 0.5Mo, 2.25Cr 1Mo, 9Cr 1 Mo V, Type 304 SS, Type 316 SS, Type 316L SS, Type 321 SS, Type 321H SS, Type 347 SS, and Type 347H SS. Results of this evaluation may be used to improve the ASME B31.1 Code, including a technical basis for a possible revision to para. 102.2.4. Previous studies have revealed that Grade P22 base metal creep damage is slightly more sensitive to stress than Grade P11 material creep rupture damage, and Grade P91 base metal creep damage is substantially more sensitive to stress than Grade P22 material creep rupture damage. Therefore, the allowable pressure and temperature variations result in a range of increased creep life consumption for different materials. The intent of this study was to modify the two Code allowance criteria so that the permitted increased creep life consumption (considering the minimum creep rupture properties of the material) of Allowance B is about the same amount as the increased creep life consumption result of Allowance A for the same material. Consequently, this study was performed to realign the allowable increased creep rupture life consumption of Allowance B to be approximately equivalent to the allowable increased creep life consumption of Allowance A. If the Allowance B event duration is increased from 80 hours per year to 400 hours per year, the Allowance B increased creep life consumption is slightly less than the Allowance A life consumption for each of these materials.

Creep Rupture Behavior of Selected Turbine Materials in Air, Ultra-High Purity Helium, and Simulated Closed Cycle Brayton Helium Working Fluids

1980 ◽  
Author(s):  
R. L. Ammon ◽  
L. R. Eisenstatt ◽  
G. O. Yatsko
Keyword(s):  
High Purity ◽  
Creep Rupture ◽  
Working Fluid ◽  
Closed Cycle ◽  
Working Fluids ◽  
Ultra High Purity ◽  
Rupture Properties ◽  
Rupture Behavior

Five turbine materials, IN100, 713LC, MAR-M-509, MA-754 and TZM were selected as candidate materials for use in a Compact Closed Cycle Brayton System (CCCBS) study in which helium served as the working fluid. The suitability of the alloys to serve in the CCCBS environment at 927 C (1700 F) was evaluated on the basis of creep-rupture tests conducted in air, ultra-high purity helium (> 99.9999 percent), and a controlled impurity helium environment. Baseline reference creep rupture properties for times up to 10,000 hr were established in a static ultra-high purity helium enviroment.

Sign in / Sign up

Export Citation Format

Share Document