Viability of turbine blade material with a long service life

Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
M. K. Chegurov

This article deals with structural features and characteristic changes that affect the mechanical characteristics after different service life in real conditions using the example of the blades of the 4th stage of turbine GTE-45-3 with an operating time of 13,000 to 100,000 hours. To study the change in the state of the material under different operating conditions, determine the degree of influence of heat treatment on the regeneration of the microstructure, and restore the mechanical characteristics of the alloy after different periods of operation, non-standard methods were used: relaxation tests on miniature samples to determine the physical yield strength and microplasticity limit and quantitative evaluation of the plasticity coefficient of the material from experimental values of hardness, which allow us to identify the changes occurring in the microvolumes of the material and predict the performance of the product as a whole.

2018 ◽  
Vol 29 (19) ◽  
pp. 3737-3747 ◽  
Author(s):  
Tobias Bauerochs ◽  
Stephan Ulrich ◽  
Steffen Schneider ◽  
Rainer Bruns

This work presents an approach on the improvement of the durability of an electrorheological valve and an electrorheological fluid. The pressure difference which can be achieved with the electrorheological effect is determined at the electrorheological valve. In order to simulate realistic operating conditions and to obtain a time-dependent pressure difference, several experiments are carried out in which the electrorheological fluid is permanently loaded over a period of several days with a field strength of up to 5 kV/mm. The results show that a simulated operating time of 2000 h would be possible without any problems. The knowledge gained on the characteristics of the electrorheological valve and electrorheological fluid in continuous operation is important for the design of electrorheological applications in order to estimate and determine their service life.


2020 ◽  
Vol 329 ◽  
pp. 02041
Author(s):  
O. B. Berdnik ◽  
I. N. Tsareva ◽  
L. A. Krivina

The article presents the results of studies of the post-operational state of the turbine rotor blade material of the power plant (operating time is about 30000 hours). High-temperature fatigue processes occurring in the heat-resistant steel 15Cr12WNiМoV have been studied. These processes manifested themselves in changing microstructure and mechanical characteristics. Various heat treatment modes were tested to regenerate the structure and restore the mechanical properties of the alloy in order to develop the scientific foundations of the resource-saving technology of turbine blades.


Alloy Digest ◽  
1966 ◽  
Vol 15 (8) ◽  

Abstract AW-TEN is a high-strength structural steel offering 50,000 psi minimum yield strength, good formability and weldability, and superior corrosion resistance. It is intended primarily for weight reduction and longer service life. It is recommended for automobile and truck bodies, buildings, bridges, railway cars, booms, etc. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive and bend strength as well as fracture toughness and fatigue. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-199. Producer or source: Alan Wood Steel Company.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 555
Author(s):  
Sangkyung Na ◽  
Sanghun Song ◽  
Seunghyuk Lee ◽  
Jehwan Lee ◽  
Hyun Kim ◽  
...  

In this study, evaporator optimization, via both experimental and simulation methods was conducted. To evaluate the evaporator performance, under the optimal system, the compressor operating time and the effects of oil on the refrigerator system were studied. If the temperature of the refrigerator chamber reaches the setting value, the compressor stops working and it leads to the temperature of the refrigerator chamber slowly increasing, due to the heat transfer to the ambient. When the refrigerator temperature is out of the setting range, the compressor works again, and the refrigerator repeats this process until the end of its life. These on/off period can be controlled through the compressor piston movement. To determine the optimal compressor operating conditions, experiments of monthly power consumption were conducted under various compressor working times and the lowest power consumption conditions was determined when the compressor worked continuously. Lubricating oil, the refrigerator system, using oil, also influenced the system performance. To evaluate the effect of oil, oil eliminated and oil systems were compared based on cooling capacity and power consumption. The cooling capacity of the oil eliminated system was 2.6% higher and the power consumption was 3.6% lower than that of the oil system. After determining the optimal operating conditions of the refrigerator system, visualization experiments and simulations were conducted to decide the optimal evaporator and the conventional evaporator size can be reduced by approximately 2.9%.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1496
Author(s):  
Svetislav Marković ◽  
Dušan Arsić ◽  
Ružica R. Nikolić ◽  
Vukić Lazić ◽  
Nada Ratković ◽  
...  

This paper presents the results of voluminous experimental investigations conducted to analyze the influence of the welding procedure on the performance of regenerated gears. Cylindrical spur gears were tested, both newly manufactured and regenerated, in two fundamentally different ways: by hard facing (surfacing) with the “hard” filler metal (DUR 600-IG) and with the “soft” filler metal (EVB2CrMo) with subsequent cementation and quenching. The regeneration procedures were defined and executed, while, subsequently, the microstructure and microhardness of the hard-faced layers were established and measured, followed by checking the durability of the hard-faced teeth flanks. Finally, techno-economic analysis was performed to establish the rationality of the conducted regenerations, i.e., the costs of regenerated and newly manufactured teeth were compared. Based on the results of the conducted investigations, it was possible to establish the influence of the welding type on the performance characteristics (primarily the service life) of the regenerated gears. For individual reparatory hard facing, the procedure with the “hard” filler metal exhibited better characteristics, while for batch reparation of numerous damaged gears, the reparation with the “soft” filler metal, followed by cementation and heat treatment, might be more convenient.


Author(s):  
Zumrat Usmanova ◽  
Emin Sunbuloglu

Numerical simulation of automotive tires is still a challenging problem due to their complex geometry and structures, as well as the non-uniform loading and operating conditions. Hysteretic loss and rolling resistance are the most crucial features of tire design for engineers. A decoupled numerical model was proposed to predict hysteretic loss and temperature distribution in a tire, however temperature dependent material properties being utilized only during the heat generation analysis stage. Cyclic change of strain energy values was extracted from 3-D deformation analysis, which was further used in a thermal analysis as input to predict temperature distribution and thermal heat generation due to hysteretic loss. This method was compared with the decoupled model where temperature dependence was ignored in both deformation and thermal analysis stages. Deformation analysis results were compared with experimental data available. The proposed method of numerical modeling was quite accurate and results were found to be close to the actual tire behavior. It was shown that one-way-coupled method provides rolling resistance and peak temperature values that are in agreement with experimental values as well.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 884
Author(s):  
Andrzej Borawski

Braking systems have a direct impact on the safety of road users. That is why it is crucial that the performance of brakes be dependable and faultless. Unfortunately, the operating conditions of brakes during their operating time are affected by many variables, which results in changes in their tribological properties. This article presents an attempt to develop a methodology for studying how the operating time affects the value of the coefficient of friction and the abrasive wear factor. The Taguchi method of process optimization was used to plan the experiment, which was based on tests using the ball-cratering method. The results clearly show that the degree of wear affects the properties of the friction material used in the production process of brakes.


2020 ◽  
Vol 836 ◽  
pp. 41-45
Author(s):  
S.N. Dzhabbarov ◽  
E.I. Pryakhin

Development of an optimal technology of heat treatment for blanks of the casing pipe made of steel 40H (GOST 4543) is used in the oil and gas industry for casing. It is accompanied by quenching in various environments to ensure guaranteed obtainment of the required mechanical characteristics. These characteristics are specified in GOST 632-80 and met in order to improve the properties of the 40H steel.


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