Life Prediction of Thermo-Mechanical Fatigue for Nickel Based Superalloy IN738LC

2006 ◽  
Vol 326-328 ◽  
pp. 953-956
Author(s):  
Jung Seob Hyun ◽  
Gee Wook Song ◽  
Young Shin Lee

An experimental program has been carried out to address the thermo-mechanical fatigue life of the uncoated IN738LC nickel-base superalloy. High temperature isothermal Fatigue and out-of-phase(OP), in-phase(IP) TMF experiments in strain control were performed on superalloy materials. Temperature interval of 450-850 was applied to thermo-mechanical fatigue tests. The stress-strain response and the life cycle of the material were measured during the test. The plastic strain energy based life pediction models were applied to the stress-strain history effect on the thermo-mechanical fatigue lives.

2006 ◽  
Vol 321-323 ◽  
pp. 509-512 ◽  
Author(s):  
Jung Seob Hyun ◽  
Gee Wook Song ◽  
Young Shin Lee

A more accurate life prediction for gas turbine blade takes into account the material behavior under the complex thermo-mechanical fatigue (TMF) cycles normally encountered in turbine operation. An experimental program has been carried out to address the thermo-mechanical fatigue life of the IN738LC nickel-base superalloy. High temperature out-of-phase and in-phase TMF experiments in strain control were performed on superalloy materials. Temperature interval of 450-850 was applied to thermo-mechanical fatigue tests. The stress-strain response and the life cycle of the material were measured during the test. The mechanisms of TMF damage is discussed based on the microstructural evolution during TMF. The plastic strain energy based life pediction models were applied to the stress-strain history effect on the thermo-mechanical fatigue lives.


1990 ◽  
Vol 112 (1) ◽  
pp. 68-79 ◽  
Author(s):  
D. A. Boismier ◽  
Huseyin Sehitoglu

Isothermal fatigue tests, out-of-phase and in-phase thermo-mechanical fatigue tests were performed on Mar-M247 nickel-based superalloy. The experiments were conducted in the temperature range 500°C to 871°C. Results indicate that the lives differ with strain-temperature phasing and with strain rate. The results of out-of-phase thermo-mechanical tests correspond well with strain-life data of isothermal tests conducted at the peak temperature (871°C). However, the in-phase thermo-mechanical results differed depending on the strain amplitude. Significant surface and crack tip oxidation and gamma prime depletion has been observed based on metallographic and Auger Spectroscopic analyses. These changes were measured as a function of time. The environment induced changes significantly influenced the fatigue lives in isothermal and out-of-phase thermo-mechanical fatigue cases. In these cases transgranular cracking was observed. Grain boundary crack nucleation and grain boundary crack growth dominated the in-phase thermo-mechanical fatigue cases. Based on these observations the requirements for a life prediction model are outlined. The life prediction model and the predictions are given in Part 2 of this paper.


Author(s):  
Ernst E. Affeldt

TMF tests were conducted with bare and aluminide coated single crystal nickel-based superalloy specimens. Temperature cycling was between 400°C and 1100°C with a phase shift (135°) which is typical for damaged locations on turbine blades. Stress response is characterized by a constant range and the formation of a tensile mean stress as a result of relaxation in the high temperature part of the cycle which is in compression. Bare specimens showed crack initiation from typical oxide hillocks. Coated specimens showed life reduction with respect to the bare ones caused by brittle cracking of the coating in the low temperature part of the cycle. Isothermal bending tests of coated specimens confirmed the low ductility of the coating at tempeatures below 600°C but quantitative correlation with the TMF test results failed.


2016 ◽  
Vol 40 (2) ◽  
pp. 777-787 ◽  
Author(s):  
A. García de la Yedra ◽  
J. L. Pedrejón ◽  
A. Martín-Meizoso ◽  
R. Rodríguez

2017 ◽  
Vol 891 ◽  
pp. 420-425
Author(s):  
Sureerat Polsilapa ◽  
Aimamorn Promboopha ◽  
Panyawat Wangyao

Cast nickel based superalloy, Grade Inconel 738, is a material for turbine blades. Its rejuvenation heat treatment usually consist of solution treatment condition with temperature range of 1125-1205 oC for 2-6 hours. Then it is following with double aging process including primary aging at 1055oC for 1 hour and secondary aging at 845oC for 24 hours. However, the various selected temperature dropping program were performed during solution treatment to simulate the possible error of heating furnace. The maximum number of temperature dropping during solution treatment is varied from 1-3 times From all obtained results, the various temperature dropping during solution treatment conditions showed extremely the significant effect on the final rejuvenated microstructures and long-term gamma prime stability after heating at temperature of 900oC for 200 hours.


2010 ◽  
Vol 431-432 ◽  
pp. 162-165
Author(s):  
Xin Yong Wang ◽  
Si Qin Pang ◽  
Qi Xun Yu

Nickel-based superalloy is one kind of typical hard-processing materials, its cutting force is more complicated than other materials. Studies have shown that Response Surface Methodology model is more suitable than classical linear regression model, especially regression coefficients are more significantly. And the analysis of the linear effects , secondary effects and interactions effects can be more effective ,so as to achieve a good effect of cutting force prediction, to provide a reliable basis for a reasonable choice of processing parameters.


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