Creep rupture life assessment of superheater tube with oxide formation in power plant

2020 ◽  
Vol 71 (12) ◽  
pp. 2029-2037
Author(s):  
Jing Qi ◽  
Hong Xu ◽  
Ping Lu ◽  
Keyi Zhou
Keyword(s):  
Power Plant ◽  
Rupture Life ◽  
Creep Rupture ◽  
Life Assessment ◽  
Oxide Formation ◽  
Superheater Tube

Introduction of SCRI model for creep rupture life assessment

2009 ◽  
Vol 86 (9) ◽  
pp. 599-603 ◽  
Author(s):  
Jie Zhao ◽  
Dong-ming Li ◽  
Jun-shan Zhang ◽  
Wei Feng ◽  
Yuan-yuan Fang
Keyword(s):  
Rupture Life ◽  
Creep Rupture ◽  
Life Assessment

A Grain Size-Dependent Equation for Creep Rupture Life of Grade 91 Steel Verified Up To 233,000 Hours

2020 ◽  
Vol 142 (6) ◽  
Author(s):  
K. Maruyama ◽  
N. Sekido ◽  
K. Yoshimi ◽  
Y. Yamamoto
Keyword(s):  
Grain Size ◽  
Rupture Life ◽  
Creep Rupture ◽  
Life Assessment ◽  
Size Dependent ◽  
Grade 92 Steel ◽  
Grade 91 ◽  
Steam Pipes ◽  
Grade 91 Steel

Abstract Grade 91 steel is widely used as steam pipes in ultrasupercritical (USC) steam boilers. In residual creep life assessment of the pipes by calculation, one needs creep rupture life of the steel as a function of stress and temperature in a time range longer than 105 h. Four regions with different creep rupture characteristics appear in a stress versus creep rupture life diagram of the steel. Main steam pipes made of the steel are used in a long-term region with low values of stress exponent and activation energy for creep rupture life (referred to as region G in this paper). Creep rupture lives of the steel in this region vary from heat to heat depending on their prior austenite grain size. This paper proposes a grain size-dependent equation representing creep rupture life of the steel in region G. The equation is verified with creep rupture data up to 232,833 h at 600 °C. Region G is absent in some heats with a large grain size. The equation can rationalize the absence in the heats. In a stress versus creep rupture life diagram of grade 92 steel, there is the same long-term region G. In the region, a creep rupture life of each heat is dependent on its grain size as is the case in grade 91 steel. The proposed equation accords well with the creep rupture lives of the grade 92 steel in region G.

Creep rupture analysis and remaining life assessment of 2.25Cr–1Mo steel tubes from a thermal power plant

2007 ◽  
Vol 454-455 ◽  
pp. 679-684 ◽  
Author(s):  
A.K. Ray ◽  
Y.N. Tiwari ◽  
P.K. Roy ◽  
S. Chaudhuri ◽  
S.C. Bose ◽  
...  
Keyword(s):  
Power Plant ◽  
Thermal Power Plant ◽  
Thermal Power ◽  
Creep Rupture ◽  
Life Assessment ◽  
Remaining Life ◽  
Steel Tubes ◽  
Remaining Life Assessment

Estimation of Long-Term Creep Rupture Life of T91 Alloy Superheater Tube in the Presence of Steam-Side Oxide Scales

2012 ◽  
Author(s):  
Junlin Huang ◽  
Keyi Zhou ◽  
Jianqun Xu ◽  
Xiaohu Xu
Keyword(s):  
Survival Probability ◽  
Rupture Life ◽  
Estimation Method ◽  
Creep Rupture ◽  
Tube Diameter ◽  
Steam Flow ◽  
Steam Temperature ◽  
Superheater Tube ◽  
Term Creep

Taking into account the effects that steam-side oxidation has on the effective load-bearing thickness and temperature of tube wall, a systematic probabilistic estimation method for the long-term creep rupture life of T91 alloy superheater tube is proposed in this work. The new creep strength assessment results of T91 alloy are utilized. Considering the influence of uncertain factors including the geometry dimensions and operational conditions, instead of usual deterministic methods, probabilistic life estimation is performed. A concept referred to as survival probability which reflects the possibility for the long-term creep rupture life to be longer than a given time is defined, and the effects of initial inner tube diameter, steam temperature and steam flow on the survival probability are analyzed. The results reveal that the increase of initial inner tube diameter or the steam temperature will decrease the survival probability, while the steam flow has an opposite effect. Measures that can be adopted to improve survival probability are also introduced. This work can provide reference for the design of high temperature steam generation components in coal-fired power plants. Besides, it is also expected that this work can guide the determination of metallographic inspection and replacement schedule of these components.

Effects of microstructure and lattice misfit on creep life of Ni-based single crystal superalloy during long-term thermal exposure

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenyan Gan ◽  
Hangshan Gao ◽  
Haiqing Pei ◽  
Zhixun Wen
Keyword(s):  
Single Crystal ◽  
Rupture Life ◽  
Precipitation Amount ◽  
Lattice Misfit ◽  
Thermal Exposure ◽  
Phase Evolution ◽  
Creep Rupture ◽  
Simultaneous Increase ◽  
Creep Life ◽  
The Matrix

Abstract According to the microstructural evolution during longterm thermal exposure at 1100 °C, the creep rupture life of Ni-based single crystal superalloys at 980 °C/270 MPa was evaluated. The microstructure was characterized by means of scanning electron microscopy, X-ray diffraction and related image processing methods. The size of γ’ precipitates and the precipitation amount of topologically close-packed increased with the increase in thermal exposure time, and coarsening of the γ’ precipitates led to the simultaneous increase of the matrix channel width. The relationship between the creep rupture life and the lattice misfit of γ/γ’, the coarsening of γ’ precipitate and the precipitation of TCP phase are systematically discussed. In addition, according to the correlation between γ’ phase evolution and creep characteristics during thermal exposure, a physical model is established to predict the remaining creep life.

Long Term Creep Properties of a Die-Cast Mg-Al-Ca Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 163-166
Author(s):  
Yoshihiro Terada ◽  
Tatsuo Sato
Keyword(s):  
Creep Rate ◽  
Magnesium Alloys ◽  
Cast Alloy ◽  
Rupture Life ◽  
Testing Temperature ◽  
Creep Rupture ◽  
Die Cast ◽  
Cast Magnesium Alloys ◽  
Term Creep ◽  
Cast Magnesium

Creep rupture tests were performed for a die-cast Mg-Al-Ca alloy AX52 (X representing calcium) at 29 kinds of creep conditions in the temperature range between 423 and 498 K. The creep curve for the alloy is characterized by a minimum in the creep rate followed by an accelerating stage. The minimum creep rate (ε& m) and the creep rupture life (trup) follow the phenomenological Monkman-Grant relationship; trup = C0 /ε& m m. It is found for the AX52 die-cast alloy that the exponent m is unity and the constant C0 is 2.0 x 10-2, independent of creep testing temperature. The values of m and C0 are compared with those for another die-cast magnesium alloys. The value m=1 is generally detected for die-cast magnesium alloys. On the contrary, the value of C0 sensitively depends on alloy composition, which is reduced with increasing the concentration of alloying elements such as Al, Zn and Ca.

Reliability assessment of creep rupture life for Gr. 91 steel

2013 ◽  
Vol 51 ◽  
pp. 1045-1051 ◽  
Author(s):  
Woo-Gon Kim ◽  
Jae-Young Park ◽  
Seon-Jin Kim ◽  
Jinsung Jang
Keyword(s):  
Rupture Life ◽  
Reliability Assessment ◽  
Creep Rupture

scholarly journals CREEP RUPTURE LIFE OF PRE-STRAINED SUPERALLOY N07080

2021 ◽  
Vol 9 (10) ◽  
pp. 1167-1176
Author(s):  
Omer Beganovic ◽  
Keyword(s):  
Stress Concentration ◽  
Grain Boundaries ◽  
Rupture Life ◽  
Warm Rolling ◽  
Creep Rupture ◽  
Cavity Nucleation ◽  
Standard Heat ◽  
Creep Cavity ◽  
Heat Treated

The creep of the pre-strained superalloy N07080 is described in this work. The pre-strain was achieved by warm rolling at 1050 oC.-The warm rolling was performed due to additional strengthening, i.e increasing of the superalloy hardness.-The pre-strain drastically reduces the creep rupture life of the superalloy compared to the creep rupture life of the standard heat treated superalloy.-The drastic reductionof the creep rupture life is result of rapid creep cavity nucleation on stress concentration sites along primary grain boundaries of the pre-strained superalloy.-Recrystallization eliminates potential sites for rapid cavity nucleation and prolongates the creep rupture life.

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