A tension—torsion creep-rupture testing machine

1980 ◽  
Vol 15 (3) ◽  
pp. 151-157 ◽  
Author(s):  
W Trampczynski ◽  
C Morrison ◽  
W E Topliss
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Continuous Measurement ◽  
Testing Machine ◽  
Gauge Length ◽  
Creep Rupture ◽  
High Temperature Creep ◽  
Air Bearing ◽  
Creep Tests ◽  
Shear Strains

The paper discusses the design and construction of a high-temperature creep machine capable of applying combined tension and torsion loadings. The design utilizes an air bearing and pinned universal joints to achieve axiality of loading. An extensometer is described which transmits the deformation of the specimen gauge length outside the furnace and allows the continuous measurement of axial and shear strains to be made using linear variable differential transducers at room temperature. Results of elastic and creep tests are presented which show the performance of the machine to be satisfactory.

Design-development of a variable load tension—compression creep testing machine

1986 ◽  
Vol 21 (1) ◽  
pp. 25-31
Author(s):  
C J Morrison ◽  
D R Hayhurst
Keyword(s):  
High Temperature ◽  
Testing Machine ◽  
High Accuracy ◽  
Gauge Length ◽  
Ball Screw ◽  
Variable Load ◽  
High Temperature Creep ◽  
Design Development ◽  
Dead Weight ◽  
Compression Creep

The design and development is described of a variable load tension-compression creep machine (±50 kN) which overcomes the disadvantages of servo-hydraulic and recirculating ball screw testing machines. The use of dead weight levers to apply specimen loads ensures the achievement of low running costs. Screwed end specimens are used with a 25.40 mm parallel sided gauge length and a diameter of 12.70 mm. It is shown that, provided modest rates of loading (0.4 kN/s) are used, high accuracy ‘through zero’ loadings can be achieved. The machine has been shown to operate satisfactorily for long periods under tension-compression high temperature creep.

Cantilever creep method for testing ceramic composites and a case study for chemically bonded phosphate ceramic composites reinforced with glass, carbon and basalt fibers, including both experiments and simulations

2020 ◽  
Vol 54 (20) ◽  
pp. 2663-2676
Author(s):  
Henry A Colorado ◽  
Elkin I Gutiérrez-Velásquez ◽  
Clem Hiel
Keyword(s):  
High Temperature ◽  
Large Scale ◽  
Extreme Environments ◽  
Ceramic Composites ◽  
High Temperature Creep ◽  
Creep Tests ◽  
Element Analysis ◽  
Temperature Creep ◽  
Glass Carbon ◽  
Electron Microscopy Analysis

This paper presented the cantilever beam experiments and the method for creep in chemically bonded ceramics reinforced with glass, carbon, and basalt unidirectional fibers. The ceramic composite samples were fabricated by mixing wollastonite powder and phosphoric acid, through the resonant acoustic mixing technique. The reinforced fibers were added via pultrusion process. The manufactured materials were exposed to high temperature creep tests at 600, 800 and 1000℃, with an annealing time of 1 h, all in air environment. Some examples of real large-scale structures made manually by a company were also included. In order to understand the microstructure, X-ray diffraction and scanning electron microscopy analysis were included. The presented method is simple and can be used in any inorganic ceramic slurry types, such as geopolymers, phosphate cements, clay-based materials, or Portland cement composites. The sample response in high temperature creep experiments was analyzed with a new but very simple technique, and modeled using finite element analysis over all compositions. Results revealed that fibers have a significant effect on the composite creep when compared to the ceramic without reinforcement, and particularly carbon fibers showed a quite interested effect in reducing the creep effects. Results show the limit of the materials under conditions typically found in fires and other extreme environments.

Progress in the Design of an Improved High-Temperature 1 Percent CrMoV Rotor Steel

1990 ◽  
Vol 112 (1) ◽  
pp. 99-115 ◽  
Author(s):  
R. L. Bodnar ◽  
J. R. Michael ◽  
S. S. Hansen ◽  
R. I. Jaffee
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Room Temperature ◽  
Rupture Strength ◽  
Temper Embrittlement ◽  
Creep Rupture ◽  
Rotor Steel ◽  
Creep Rupture Strength ◽  
Austenitizing Temperature ◽  
Creep Ductility

Silicon-deoxidized, tempered bainitic 1 percent CrMoV steel is currently used extensively for high-temperature steam turbine rotor forgings operating at temperatures up to 565°C due to its excellent creep rupture properties and relative economy. There is impetus to improve the creep rupture strength of this steel while maintaining its current toughness level and vice versa. The excellent creep rupture ductility of the low Si version of this steel allows the use of a higher austenitizing temperature or tensile strength level for improving creep rupture strength without loss in creep ductility or toughness. When the tensile strength of this steel is increased from 785 to 854 MPa, the creep rupture strength exceeds that of the more expensive martensitic 12CrMoVCbN steel currently used for high-temperature rotor applications where additional creep rupture strength is required. The toughness of 1 percent CrMoV steel is improved by lowering the bainite start (Bs) temperature in a “superclean” base composition which is essentially free of Mn, Si, P, S, Sb, As and Sn. The Bs temperature can be lowered through the addition of alloying elements (i.e., C, Ni, Cr, and Mo) and/or increasing the cooling rate from the austenitizing temperature. Using these techniques, the 50 percent FATT can be lowered from approximately 100°C to below room temperature, which provides the opportunity to eliminate the special precautionary procedures currently used in the startup and shutdown of steam turbines. The most promising steels in terms of creep rupture and toughness properties contain 2.5 percent Ni and 0.04 percent Cb (for austenite grain refinement and enhanced tempering resistance). In general, the creep rupture strength of the superclean steels equals or exceeds that of the standard 1 percent CrMoV steel. In addition, the superclean steels have not been found to be susceptible to temper embrittlement, nor do they alter the room temperature fatigue crack propagation characteristics of the standard 1 percent CrMoV steel. These new steels may also find application in combination high-temperature-low-temperature rotors and gas turbine rotors.

Evaluation of Creep Properties of Alloy 690 Steam Generator Tubes at High Temperature Using Tube Specimen

2019 ◽  
Author(s):  
Jongmin Kim ◽  
Woogon Kim ◽  
Minchul Kim
Keyword(s):  
High Temperature ◽  
Steam Generator ◽  
Creep Test ◽  
Rupture Life ◽  
Creep Rupture ◽  
Severe Accident ◽  
High Temperature Creep ◽  
Creep Life ◽  
Temperature Creep ◽  
Alloy 690

Abstract Thermally induced steam generator (SG) tube failures caused by hot gases from a damaged reactor core can result in a containment bypass event and may lead to release of fission products to the environment. A typical severe accident scenario is a station blackout (SBO) with loss of auxiliary feedwater. Alloy 690 which has increased the Cr content has been replaced for the SG tube due to its high corrosion resistance against stress corrosion cracking (SCC). However, there is lack of research on the high temperature creep rupture and life prediction model of Alloy 690. In this study, creep test was performed to estimate the high temperature creep rupture life of Alloy 690. Based on reported creep data and creep test results of Alloy 690 in this study, creep life extrapolation was carried out using Larson-Miller Parameter (LMP), Orr-Sherby-Dorn (OSD), Manson-Haferd Parameter (MHP), and Wilshire’s approach. And a hyperbolic sine (sinh) function to determine master curves in LMP, OSD and MHP methods was used for improving the creep life estimation of Alloy 690 material.

scholarly journals Compliance-Derived Strain Determination in Fibre (Bundle) Tests at High Temperatures

1998 ◽  
Vol 7 (3) ◽  
pp. 096369359800700 ◽  
Author(s):  
R. Paar ◽  
P. Bonnel ◽  
M. Steen
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Strain Measurement ◽  
Fibre Bundle ◽  
Testing Machine ◽  
Tensile Tests ◽  
Gauge Length ◽  
Head Displacement ◽  
The Cross ◽  
Strain Determination

In high temperature fibre tensile tests direct strain measurement is not a straightforward task, due to the limited accessibility and the fragile nature of the specimen. A compliance method which allows to determine the true specimen strain within the gauge length from the cross head displacement of the testing machine is presented.

Study on High-Temperature Creep Behavior of T23 and T24 Steels

2018 ◽  
Vol 789 ◽  
pp. 182-186
Author(s):  
Jin Ping Pan ◽  
Shu Heng Tu ◽  
Ding Jun Chu ◽  
Xin Wei Zhu ◽  
Bin Hu ◽  
...  
Keyword(s):  
High Temperature ◽  
Creep Behavior ◽  
Rupture Strength ◽  
Progressive Increase ◽  
High Temperature Creep ◽  
Creep Tests ◽  
Theoretical Simulation ◽  
Temperature Creep ◽  
Piping Systems ◽  
Different Temperatures

A progressive increase of plant efficiency calls for new requirements of heat-resistantsteels used in the boiler and piping systems. In this paper, high-temperature creep behavior of T23and T24 steels were studied. Creep tests over a long period of time have been conducted for bothsteels at different temperatures. The creep mechanisms of the two steels have been clarified byanalyzing the minimum creep rate versus stress data. Besides, the creep rupture data from the creeptests were in good accordance with theoretical simulation on the basis of the CDM model over a longtime. Creep temperature has great effects on the rupture strength of the two steels. By creep ruptureexperiments and appropriate modelling, the high-temperature creep behavior can be well described.

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