Creep-Fatigue Behavior of a Newly Developed Ultra-Supercritical Steam Turbine Grade Nickel-Based Superalloy, HAYNES 282

2021 ◽  
Vol 10 (2) ◽  
pp. 20200167
Author(s):  
Shreya Mukherjee ◽  
Kaustav Barat ◽  
Soumitra Tarafder ◽  
S. Sivaprasad ◽  
Sujoy Kumar Kar
Keyword(s):  
Steam Turbine ◽  
Fatigue Behavior ◽  
Nickel Based Superalloy ◽  
Creep Fatigue

Analysis of Multi-Axial Creep–Fatigue Damage on an Outer Cylinder of a 1000 MW Supercritical Steam Turbine

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Weizhe Wang
Keyword(s):  
Steam Turbine ◽  
Fatigue Damage ◽  
Damage Mechanics ◽  
Hydrostatic Stress ◽  
Fatigue Behavior ◽  
Axial Stress ◽  
Outer Cylinder ◽  
Continuum Damage Mechanics ◽  
Transfer Coefficients ◽  
Creep Fatigue

A multi-axial continuum damage mechanics (CDM) model was proposed to calculate the multi-axial creep–fatigue damage of a high temperature component. A specific outer cylinder of a 1000 MW supercritical steam turbine was used in this study, and the interaction of the creep and fatigue behavior of the outer cylinder was numerically investigated under a startup–running–shutdown process. To this end, the multi-axial stress–strain behavior of the outer cylinder was numerically studied using Abaqus. The in-site measured temperatures were provided to validate the heat transfer coefficients, which were used to calculate the temperature field of the outer cylinder. The multi-axial mechanics behavior of the outer cylinder was investigated in detail, with regard to the temperature, Mises stress, hydrostatic stress, multi-axial toughness factor, multi-axial creep strain, and damage. The results demonstrated that multi-axial mechanics behavior reduced the total damage.

Effect of notches on creep–fatigue behavior of a P/M nickel-based superalloy

2016 ◽  
Vol 87 ◽  
pp. 311-325 ◽  
Author(s):  
J. Telesman ◽  
T.P. Gabb ◽  
L.J. Ghosn ◽  
J. Gayda
Keyword(s):  
Fatigue Behavior ◽  
Nickel Based Superalloy ◽  
Creep Fatigue

High-temperature hot-corrosion effects on the creep–fatigue behavior of a directionally solidified nickel-based superalloy: Mechanism and lifetime prediction

2019 ◽  
Vol 29 (5) ◽  
pp. 798-809
Author(s):  
Shaolin Li ◽  
Xiaoguang Yang ◽  
Hongyu Qi
Keyword(s):  
High Temperature ◽  
Hot Corrosion ◽  
Damage Accumulation ◽  
Fatigue Behavior ◽  
Coated Sample ◽  
Directionally Solidified ◽  
Accumulation Model ◽  
Nickel Based Superalloy ◽  
Creep Fatigue ◽  
Damage Accumulation Model

Creep–fatigue experiments were performed at 850℃ on bare and salt-coated directionally solidified Ni-based superalloy DZ125. Experimental test results showed that the salt-coated sample exhibited lower lifetime than that of the bare sample under all stress conditions. This reduction is found to correlate directly with the higher probability of crack initiation, due to surface micro-structural degradation and higher actual stress as a result of the decrease in effective bearing area. A modified damage accumulation model considering the creep, fatigue, and hot-corrosion interaction effect was proposed to predict the corrosion–creep–fatigue lifetime. In this model, a critical high-temperature hot-corrosion exposure time was proposed and was introduced using the Miller linear damage accumulation model. The predicted lifetimes correspond remarkably well with the experimental results.

Numerical Investigation of Creep–Fatigue Behavior in a Steam Turbine Inlet Valve Under Cyclic Thermomechanical Loading

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Weizhe Wang ◽  
Sihua Xu ◽  
Yingzheng Liu
Keyword(s):  
Steam Turbine ◽  
Contact Stress ◽  
Damage Mechanics ◽  
Fatigue Behavior ◽  
Thermomechanical Loading ◽  
Inlet Valve ◽  
Valve Body ◽  
Turbine Inlet ◽  
Creep Fatigue ◽  
Cyclic Thermomechanical Loading

The aim of this study was to investigate the cyclic creep–fatigue interaction behavior in a steam turbine inlet valve under cyclic thermomechanical loading conditions. Three years and nine iterations of idealized startup–steady-state operation–shutdown process were chosen. The Ramberg–Osgood model, the Norton–Bailey law, and continuum damage mechanics were applied to describe the stress–strain behavior and calculate the damage. The strength of the steam valve revealed that significant stress variation mainly occurred at the joint parts between the valve diffuser and the adjust valve body, due to the combination of the enhanced turbulent flow and assembly force at these areas. The contact stress at the region of component assembly was sensitive to the cyclic loading at the initial iterations. The maximum decrease amplitude in the normalized contact stress between the second and the fourth iterations reached 0.12. The damage analysis disclosed that the notch of the deflector in the adjust valve had the maximum damage due to the stress concentration.

The creep-fatigue behavior of a nickel-based superalloy: Experiments study and cyclic plastic analysis

2021 ◽  
Vol 147 ◽  
pp. 106187 ◽  
Author(s):  
Li Sun ◽  
Xiao-Guang Bao ◽  
Su-Juan Guo ◽  
Run-Zi Wang ◽  
Xian-Cheng Zhang ◽  
...  
Keyword(s):  
Fatigue Behavior ◽  
Cyclic Plastic ◽  
Nickel Based Superalloy ◽  
Plastic Analysis ◽  
Creep Fatigue

scholarly journals On the creep fatigue and creep rupture behaviours of 9–12% Cr steam turbine rotor

2019 ◽  
Vol 76 ◽  
pp. 263-278 ◽  
Author(s):  
Xuanchen Zhu ◽  
Haofeng Chen ◽  
Fuzhen Xuan ◽  
Xiaohui Chen
Keyword(s):  
Steam Turbine ◽  
Turbine Rotor ◽  
Creep Rupture ◽  
Steam Turbine Rotor ◽  
Creep Fatigue

Component Low Cycle Fatigue Behavior Based on Standard Calculation Procedure and Non-Linear FEA

2017 ◽  
Author(s):  
Jürgen Rudolph ◽  
Adrian Willuweit ◽  
Steffen Bergholz ◽  
Christian Philippek ◽  
Jevgenij Kobzarev
Keyword(s):  
Power Plants ◽  
Low Cycle Fatigue ◽  
Fatigue Behavior ◽  
Hybrid Approach ◽  
Combined Cycle ◽  
Cycle Fatigue ◽  
Element Analysis ◽  
Constitutive Material Model ◽  
Standard Design ◽  
Creep Fatigue

Components of conventional power plants are subject to potential damage mechanisms such as creep, fatigue and their combination. These mechanisms have to be considered in the mechanical design process. Against this general background — as an example — the paper focusses on the low cycle fatigue behavior of a main steam shut off valve. The first design check based on standard design rules and linear Finite Element Analysis (FEA) identifies fatigue sensitive locations and potentially high fatigue usage. This will often occur in the context of flexible operational modes of combined cycle power plants which are a characteristic of the current demands of energy supply. In such a case a margin analysis constitutes a logical second step. It may comprise the identification of a more realistic description of the real operational loads and load-time histories and a refinement of the (creep-) fatigue assessment methods. This constitutes the basis of an advanced component design and assessment. In this work, nonlinear FEA is applied based on a nonlinear kinematic constitutive material model, in order to simulate the thermo-mechanical behavior of the high-Cr steel component mentioned above. The required material parameters are identified based on data of the accessible reference literature and data from an own test series. The accompanying testing campaign was successfully concluded by a series of uniaxial thermo-mechanical fatigue (TMF) tests simulating the most critical load case of the component. This detailed and hybrid approach proved to be appropriate for ensuring the required lifetime period of the component.

scholarly journals A Concise Binomial Model for Nonlinear Creep-Fatigue Crack Growth Behavior at Elevated Temperatures

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 651
Author(s):  
Jianxing Mao ◽  
Zhixing Xiao ◽  
Dianyin Hu ◽  
Xiaojun Guo ◽  
Rongqiao Wang
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Dwell Time ◽  
Elevated Temperatures ◽  
Nonlinear Creep ◽  
Nickel Based Superalloy ◽  
Proposed Model ◽  
Creep Fatigue ◽  
Creep Fatigue Crack

The creep-fatigue crack growth problem remains challenging since materials exhibit different linear and nonlinear behaviors depending on the environmental and loading conditions. In this paper, we systematically carried out a series of creep-fatigue crack growth experiments to evaluate the influence from temperature, stress ratio, and dwell time for the nickel-based superalloy GH4720Li. A transition from coupled fatigue-dominated fracture to creep-dominated fracture was observed with the increase of dwell time at 600 °C, while only the creep-dominated fracture existed at 700 °C, regardless of the dwell time. A concise binomial crack growth model was constructed on the basis of existing phenomenal models, where the linear terms are included to express the behavior under pure creep loading, and the nonlinear terms were introduced to represent the behavior near the fracture toughness and during the creep-fatigue interaction. Through the model implementation and validation of the proposed model, the correlation coefficient is higher than 0.9 on ten out of twelve sets of experimental data, revealing the accuracy of the proposed model. This work contributes to an enrichment of creep-fatigue crack growth data in the typical nickel-based superalloy at elevated temperatures and could be referable in the modeling for damage tolerance assessment of turbine disks.

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