scholarly journals Long-Term Creep Properties of Hastelloy XR in Simulated High-Temperature Gas-Cooled Reactor Helium

1995 ◽  
Vol 32 (11) ◽  
pp. 1108-1117 ◽  
Author(s):  
Yuji KURATA ◽  
Yutaka OGAWA ◽  
Tomio SUZUKI ◽  
Masami SHINDO ◽  
Hajime NAKAJIMA ◽  
...  
Keyword(s):  
High Temperature ◽  
Creep Properties ◽  
Term Creep ◽  
High Temperature Gas

Creep Properties of Hastelloy-X Alloy for the High Temperature Gas-Cooled Reactor

2006 ◽  
Vol 326-328 ◽  
pp. 1105-1108 ◽  
Author(s):  
Woo Gon Kim ◽  
Sang Nan Yin ◽  
Woo Seog Ryu ◽  
Jong Hwa Chang
Keyword(s):  
High Temperature ◽  
Creep Data ◽  
Creep Life ◽  
Statistical Process ◽  
Hastelloy X ◽  
Creep Properties ◽  
Rupture Data ◽  
Term Creep ◽  
High Temperature Gas

The creep properties for the Hastelloy-X alloy which is one of candidate alloys for a high temperature gas-cooled reactor are presented. The creep data was obtained with different stresses at 950oC, and a number of the creep data was collected through literature surveys. All of the creep data were combined together to obtain the creep constants and to predict a long-term creep life. In the Norton’s creep law and the Monkman-Grant relationship, the creep constants, A, n, m, and m’ were obtained. Creep master curves based on the Larson-Miller parameter were presented for the standard deviations of 1σ, 2σ and 3σ. Creep life at each temperature was predicted for a longer-time rupture above 105 hours. Failure probability was also estimated by a statistical process of all the creep rupture data.

Effects of Microstructures on Strength and Fatigue Properties of Long-Term-Serviced F12 Steels

2007 ◽  
Vol 353-358 ◽  
pp. 295-298
Author(s):  
X.M. Wu ◽  
G.P. Zhang ◽  
J.Q. Zhang ◽  
W.G. Chen
Keyword(s):  
Fatigue Crack ◽  
High Temperature ◽  
Fatigue Crack Initiation ◽  
Fatigue Properties ◽  
Degradation Mechanisms ◽  
Creep Properties ◽  
Running Time ◽  
Electron Microscopes ◽  
Term Creep

Microstructures of long-term serviced F12 steel exposed at 545 °C have been investigated by electron microscopes. The hardness of the material was measured to be correlated with the variation of the microstructures. Fatigue properties of the material with different running time were evaluated and analyzed. The experimental results show that the coarsening of the precipitated carbides along boundaries and the formation of subgrains accelerate the degradation of the long-term creep properties of the steel. Fatigue crack initiation threshold from a notch linearly deceases with increasing the running time due to the variation of the distribution and the shape of the precipitated carbides. The degradation mechanisms of the F12 steel during their long-term service at high temperature are discussed.

Prediction of Long-Term Creep Properties of Zirconium-2.5 % Niobium Alloy Using Wilshire Method

2021 ◽  
Vol 10 (2) ◽  
pp. 20200146
Author(s):  
Vivek Patel ◽  
R. N. Singh ◽  
Madangopal Krishnan
Keyword(s):  
Niobium Alloy ◽  
Creep Properties ◽  
Term Creep

Grades 92 and 23: Weldability Assessment and Long-Term Performances for Power Generation Applications

2008 ◽  
Vol 580-582 ◽  
pp. 383-388
Author(s):  
Emmanuel Bauné ◽  
E. Galand ◽  
B. Leduey ◽  
G. Liberati ◽  
G. Cumino ◽  
...  
Keyword(s):  
Creep Strength ◽  
Welded Joints ◽  
Power Plants ◽  
Product Family ◽  
Base Material ◽  
Advanced Materials ◽  
Creep Properties ◽  
Steam Parameters ◽  
Term Creep

Increased efficiency and emission reduction in modern power plants lead to the use of new advanced materials with enhanced creep strength, with the objective to increase the steam parameters of power plants. With over ten years on market and wide experience related to its use, ASTM Grade 92 is becoming one of the most required materials when high service temperatures are reached (max. 610°C). Its composition, with 9%Cr and 1.5%W, gives rise to martensitic microstructures which offer very high creep strength and long term stability. The improved weldability and creep-strength between 500 and 580°C of the low alloy ASTM Grade 23, as well as a cost advantage over higher Cr materials in this temperature range, make it one of the possible candidates to meet the stringent requirements of modern power plants. Air Liquide Welding (ALW) has optimized and distributes a complete product family for the welding of Grades 23 and 92. TenarisDalmine (TD) focused on the development of Grade 23 tubes and pipes and is working on the development of Grade 92. A deep characterization work of the microstructural evolution and long term creep performances of these high temperature resistant materials was thus undertaken by ALW and TD, in collaboration with the Centro Sviluppo Materiali (CSM). The joint characterization program consisted in the assessment of welded joints creep properties. Welded joints were produced using the gas tungsten (GTAW), shielded metal (SMAW) and submerged arc welding (SAW) processes. Mechanical and creep properties of weldments were measured both in the as welded and post weld heat treated conditions and proper WPS’s were designed in a manner such that industrial production needs were satisfied. Short term creep resistance of cross weld specimens was measured to be within the base material acceptance criteria. Long term base material and cross weld creep performance evaluation are now in progress.

Microstructure and Creep Properties of AISI 316LN Steels with Niobium Additions

2005 ◽  
Vol 482 ◽  
pp. 275-278 ◽  
Author(s):  
Vlastimil Vodárek ◽  
Gabriela Rožnovská ◽  
Jaromír Sobotka
Keyword(s):  
S Phase ◽  
Creep Life ◽  
Creep Ductility ◽  
Niobium Content ◽  
Creep Properties ◽  
Size Refinement ◽  
Tertiary Stage ◽  
Type Aisi ◽  
Term Creep

The long-term creep rupture tests have been carried out on three casts of a type AISI 316LN steel at 600 and 650°C. Two of the casts investigated contained additions of 0.1 and 0.3 wt.% of niobium. The growing niobium content strongly reduced the minimum creep rate and prolonged the time to the onset of the tertiary stage of creep and also shortened this stage. The enhanced creep resistance of niobium containing steels is not accompanied by the longer creep life that might have been expected. At both temperatures of creep exposure the niobium-bearing casts displayed an inferior creep ductility. Microstructural investigations revealed that niobium provoked significant grain size refinement and the formation of Z-phase. Particles of this phase were considerably dimensionally stable. Furthermore, niobium accelerated the formation and coarsening of s-phase, h-Laves and M6(C,N). The coarse intergranular particles facilitated the formation of cavities which resulted in intergranular failure mode.

scholarly journals Influence of Heat Treatment on Long Term Creep Properties of 9Cr–W–Mo–V–Nb Steel

2010 ◽  
Vol 96 (4) ◽  
pp. 172-181
Author(s):  
Satoshi Obara ◽  
Takashi Wakai ◽  
Tai Asayama ◽  
Yoshiyuki Yamada ◽  
Takanori Nakazawa ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Creep Properties ◽  
Term Creep

Basic Study on Creep Properties of Eucalyptus Wood

2014 ◽  
Vol 911 ◽  
pp. 232-237
Author(s):  
Yuan Rong Ma ◽  
Xian Jun Li ◽  
Biao Deng ◽  
Ying She Luo
Keyword(s):  
Model Parameters ◽  
Short Term ◽  
Basic Study ◽  
Burger Model ◽  
Creep Properties ◽  
Eucalyptus Plantation ◽  
Moisture Contents ◽  
Creep Curves ◽  
Term Creep

The study tested the short-term bending creep curves of Eucalyptus Plantation Wood under different loads, moisture contents and temperatures, analyzed the influence of load, moisture content and temperature on creep of Eucalyptus. Guided by the rheological theory, the study adopted the Burger rheological model to do the curve fitting and solved the model parameters. A defect found from Burger model in simulating long-term creep properties of wood was preliminary discussed and remedied. The equivalence of creep test and relaxation one was discussed.

Prediction of Long – Term Creep Properties of Kenaf Fiber Unsaturated Polyester Composites

2014 ◽  
Vol 974 ◽  
pp. 9-14
Author(s):  
Saad A. Mutasher ◽  
Ekhlas A. Osman
Keyword(s):  
Curve Fitting ◽  
Linear Time ◽  
Unsaturated Polyester ◽  
Kenaf Fiber ◽  
Creep Properties ◽  
Polyester Composite ◽  
Term Creep ◽  
Long Term Behavior ◽  
Fitting Model

This research focuses on predicting long-term behavior of unsaturated polyester resin (UP) and kenaf unsaturated polyester composite. The objectives of these tests are to establish a relationship between stress, strain and time at constant loading and temperature. The results obtained from these tests are used in predicting the life and strength of the polymer material. Based on the 1,000 hours experimental data, curve fitting and Findley Power Law models are employed to predict long-term behavior of the material. The results showed that curve fitting model accurately predicted the non-linear time dependent creep deformation of these materials with acceptable accuracy.

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