scholarly journals Comparison of Creep Properties of Cast and Wrought Haynes 282 Superalloy

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Young-Joo Kim ◽  
Jae-Hyeun Park ◽  
Yong-Sik Ahn
Keyword(s):  
Creep Test ◽  
Deformation Mechanism ◽  
Power Plants ◽  
Cast Alloy ◽  
Rupture Life ◽  
Test Results ◽  
Creep Properties ◽  
Temperature Capability ◽  
Cast Condition

Ni-based superalloy Haynes 282 was developed as a gas turbine material for use in the ultra-supercritical (USC) stage of next-generation coal-fired power plants. Temperatures in the USC stage exceed 700°C during operation. Despite the important role of Haynes 282 in increasing the performance of high-pressure turbines, as a result of its high-temperature capability, there is little information on the microstructure, deformation mechanism, or mechanical properties of the cast condition of this alloy. In this study, we compared the creep properties of Haynes 282 cast alloy with those of its wrought alloy counterpart. The tensile test results of cast and wrought Haynes 282 alloys over the temperature range 25–800°C showed that the cast product exhibited significantly lower strength and ductility compared with the wrought product at all test temperatures. A creep test performed at 750°C showed only a slight difference in the rupture life of the two products. Based on the creep test results, the deformation mechanism is discussed.

Small Punch Creep Testing Technique for Remnant Life Assessment

2014 ◽  
Vol 592-594 ◽  
pp. 739-743 ◽  
Author(s):  
J. Ganesh Kumar ◽  
K. Laha ◽  
M.D. Mathew
Keyword(s):  
Creep Test ◽  
Rupture Life ◽  
Life Assessment ◽  
Test Results ◽  
Creep Tests ◽  
Testing Technique ◽  
Creep Properties ◽  
Small Punch ◽  
Miniature Specimens ◽  
Deflection Rate

Small punch creep (SPC) testing technique is a material non-intensive testing technique for evaluating creep behavior of materials using miniature specimens. It can be used for remnant life assessment (RLA) studies on components in service, by scooping out limited material for testing without impairing the strength of component. In order to ensure the reliability of use of SPC technique for RLA, it is necessary to establish sound database on SPC properties of the material before putting into service. In this investigation, SPC technique was used to evaluate creep properties of 316LN stainless steel using specimens of size 10 x 10 x 0.5 mm. SPC tests were conducted in load controlled mode at 923 K and at various loads. SPC curves clearly exhibited primary, secondary and tertiary creep stages. The minimum deflection rate increased and rupture life decreased with an increase in applied load. Like in conventional creep test results, the minimum deflection rate obeyed Norton’s power law and Monkman-Grant relationship. SPC test was correlated with corresponding conventional creep test. Good correlation was established between creep rupture life values evaluated from SPC tests and conventional creep tests.

Assessment of Heat-to-Heat Variation of Gr.91 Boiler Pipings by Small Punch Creep Test

2018 ◽  
Author(s):  
Shin-ichi Komazaki ◽  
Keisuke Obata ◽  
Masato Tomobe ◽  
Masatsugu Yaguchi ◽  
Akihiro Kumada
Keyword(s):  
Creep Test ◽  
Power Plants ◽  
Rupture Strength ◽  
Rupture Life ◽  
Creep Property ◽  
Type Specimen ◽  
Testing Technique ◽  
Small Disk ◽  
Small Punch ◽  
Uniaxial Creep

The small punch (SP) testing technique was applied to five heats of Gr.91 steel, which had been actually used for boiler pipings in different ultra-super critical (USC) power plants for long periods of time, to investigate the applicability of this testing technique to the assessment of heat-to-heat variation of creep property. The SP creep test was carried out at the temperature of 650°C and under the loads of 190, 230, 300 N using a small disk-type specimen (ϕ 8 × 0.5 mm). The experimental results revealed that the SP creep rupture strength (rupture life) and the deformation rate were different depending on the heat. These differences were qualitatively in good agreement with those observed in the uniaxial creep test. The results obtained in this study indicated that the SP creep testing technique could be a strong tool for the assessment of heat-to-heat variation of in-service boiler pipings.

Characterization of Creep Resistance for Local Structure of Power Plant Weldment Using SP-Creep Technique

2006 ◽  
Vol 326-328 ◽  
pp. 643-648
Author(s):  
Seung Se Baek ◽  
Il Hyun Kwon ◽  
Dong Whan Lee ◽  
Sung Mo Yang ◽  
Hyo Sun Yu
Keyword(s):  
Power Plant ◽  
Creep Test ◽  
Power Plants ◽  
Volume Fraction ◽  
Type Specimen ◽  
Creep Tests ◽  
Creep Properties ◽  
Fine Grained ◽  
Deterioration Mechanism

Power plant weldments are composed of various microstructures. Due to welding and PWHT processes, the microstructure of the base metal adjacent to fusion line is transformed into entirely different microstructures, collectively known as heat affected zone (HAZ). Creep, on the other hand, is considered as the most important deterioration mechanism of heat resistant components found in power plants. Therefore it is essential to evaluate creep properties of HAZ, which is considered to be very hazardous in weldment. Recently, most of the creep tests for HAZ are conducted using cross weld type specimen. However there are some problems with this type of creep test due to the results being largely varied according to the volume fraction of HAZ. In this paper, SP-Creep test, which has confirmed the availability for creep properties evaluation, has been conducted on each of the weldment microstructures. The results showed that each microstructure has a different creep behavior. The overall creep properties of HAZ are worse than those of the weld metal. Among the HAZ structures, fine grained HAZ has the worst creep properties.

scholarly journals Microstructural Evolution of Large Cast Haynes 282 at Elevated Temperature

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 867
Author(s):  
Yujin Yang
Keyword(s):  
Heat Treatment ◽  
Isothermal Aging ◽  
Power Plants ◽  
Post Heat Treatment ◽  
Sand Cast ◽  
Creep Properties ◽  
Heat Treated ◽  
Heat Treated Condition ◽  
Cast Condition

Haynes 282 has attracted attention for casting applications in AUSC power plants due to its good creep properties. However, the market is primarily comprised of wrought Haynes 282, while the cast version is not commercially available. In this study, the microstructure of a large traditional sand cast Haynes 282 was studied from as-cast condition to long-term heat-treated condition by combining experimental data and thermodynamic calculations. The microstructure of a large cast Haynes 282 includes γ, γ’, two types of MX, M23C6 and µ phases. After standard post heat treatment, µ phases were dissolved and precipitated as M6C. The equilibrium state was achieved after 266 h aging at 788 °C, after which γ’ particles began coarsening. These kept to a spherical morphology; the smallest misfit was found with the γ matrix. Once post heat treatment was finished, MX exhibited little morphology and compositional change during the long-term isothermal aging. Grain boundary is covered by discrete M23C6 and M6C precipitates and this morphology keeps stable during isothermal aging. No presence of the needle µ phase have been found at grain boundaries after 10,000 h aging at 788 °C. All these microstructural features indicated that cast Haynes 282 could have a high thermal stability and good creep properties.

scholarly journals Influence of normalizing and tempering temperatures on the creep properties of P92 steel

2020 ◽  
Vol 39 (1) ◽  
pp. 178-188
Author(s):  
Lakshmiprasad Maddi ◽  
Atul Ramesh Ballal ◽  
Dilip Ramkrishna Peshwe ◽  
M. D. Mathew
Keyword(s):  
Power Plants ◽  
Rupture Strength ◽  
Rupture Life ◽  
Creep Rupture ◽  
Laves Phases ◽  
P92 Steel ◽  
Creep Properties ◽  
Martensitic Microstructure ◽  
Actual Service ◽  
Rupture Properties

AbstractP92 steel is used as a piping material in ultra super critical power plants that can be operated at steam temperatures up to 650°C. The changes in the martensitic microstructure of P92 steel must be evaluated thoroughly before it is put into actual service. In this study, indigenously developed P92 steel was used. The steel was subjected to normalizing and tempering heat treatments in the range of 1,040–1,060°C and 740–780°C. The changes in the microstructure were evaluated and creep-rupture properties were studied at test temperatures of 600 and 650°C. Although normalizing temperatures influenced the microstructure and creep strength marginally, the change in tempering temperatures led to significant changes. The creep rupture strength at 600°C was influenced largely by the changes in the dislocation substructure, while the precipitation of Laves phases was a significant observation made for 650°C test temperature. Proposed mechanisms for the microstructural evolution and its consequences on the rupture life are discussed in this study.

Creep of Cast Steel P91 with Weld Joint

2014 ◽  
Vol 782 ◽  
pp. 331-334
Author(s):  
Tomás Vlasák ◽  
Jan Hakl ◽  
Pavel Novák ◽  
Jiří Sochor ◽  
Jan Čech
Keyword(s):  
High Temperature ◽  
Creep Test ◽  
Weld Joint ◽  
Martensitic Steel ◽  
Cast Steel ◽  
High Temperature Corrosion ◽  
Strength Reduction ◽  
Energy Industry ◽  
Test Results ◽  
Creep Properties

High-temperature martensitic steel P91, internationally marked GX12CrMoVNbN91, is the material used in the energy industry. Creep and high-temperature corrosion resistances are important properties that affect the application of this material at higher temperatures. Weldment reduces creep properties. This work deals with the quantification of this decrease in the case of material P91. The main focus is except the evaluation of creep test results given to the mathematical description of the weld creep strength reduction. Further metallographic analyses of weld joint after creep exposures were performed.

Modelling and Data Interpretation of Small Punch Creep Testing

2011 ◽  
Author(s):  
R. Li ◽  
T. H. Hyde ◽  
W. Sun ◽  
B. Dogan
Keyword(s):  
Large Deformation ◽  
Test Data ◽  
Creep Test ◽  
Creep Model ◽  
Test Results ◽  
Creep Tests ◽  
Creep Properties ◽  
Small Punch ◽  
Draft Code ◽  
Uniaxial Creep

The small punch testing (SPT) technique has been proposed for use in determining the creep properties of materials for which only a very small volume of material is available. A draft code of practice on SPT has been produced. However it is not, as yet, generally accepted that the data obtained from small punch tests can be directly related to those which would be obtained from conventional uniaxial creep tests. For this reason, the development of techniques suitable for the interpretation of SPT data has become very important. In this paper, a set of uniaxial creep test data has been characterised in such a way as to gain an improved understanding of the correlation between the data from small punch tests and corresponding uniaxial creep tests. Finite element (FE) analyses of small punch creep tests, using a damage mechanics based creep model, have been performed. The effect of large deformation on the determination of material properties for a creep damage model, has been investigated to take into account the large deformation nature of small punch tests. An equivalent stress, σeq, proposed by the draft code, was used to relate the SPT results to the corresponding uniaxial creep test results. A preliminary assessment of the use of small punch test results, in determining creep properties, has been presented, which includes comparisons of the failure life and equivalent minimum strain rate results obtained from SPTs with the corresponding uniaxial creep test data. Future work related to the interpretation of SPT is briefly addressed.

Development Of Spine Mobility And Muscle Elasticity Through The Pilates Method

2019 ◽  
pp. 71-77
Author(s):  
Irene-Teodora Nica
Keyword(s):  
Target Group ◽  
Test Results ◽  
Muscle Elasticity ◽  
Spine Mobility ◽  
Pilates Method ◽  
Anterior Plane

The present study aims to emphasize the role of pilates method in the improvement of the mobility of the spine in the anterior plane and the elasticity of the posterior muscles of the thigh. In this purpose, we have developed a set of appropriate exercises destined to obtain improved results of the spine mobility and muscle elasticity. Subsequent, we applied the exercises to a target group of woman and presented the comparation between the initial and final results. The interpretation of the mobility and elasticity test results are reported in the conclusions of the present study.

scholarly journals Politics, industry, and tourism: The conceptual construction of the blue highway

2020 ◽  
pp. 002252662097950
Author(s):  
Fredrik Bertilsson
Keyword(s):  
Road Network ◽  
Power Plants ◽  
Community Building ◽  
Atlantic Coast ◽  
Political Agenda ◽  
The Road ◽  
Conceptual Construction ◽  
On The Road ◽  
Post War

This article contributes to the research on the expansion of the Swedish post-war road network by illuminating the role of tourism in addition to political and industrial agendas. Specifically, it examines the “conceptual construction” of the Blue Highway, which currently stretches from the Atlantic Coast of Norway, traverses through Sweden and Finland, and enters into Russia. The focus is on Swedish governmental reports and national press between the 1950s and the 1970s. The article identifies three overlapping meanings attached to the Blue Highway: a political agenda of improving the relationships between the Nordic countries, industrial interests, and tourism. Political ambitions of Nordic community building were clearly pronounced at the onset of the project. Industrial actors depended on the road for the building of power plants and dams. The road became gradually more connected with the view of tourism as the motor of regional development.

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