scholarly journals Heat Treatments Effects on Nickel-Based Superalloy Inconel 713C

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 47 ◽  
Author(s):  
Breno Boretti Galizoni ◽  
Antônio Augusto Couto ◽  
Danieli Aparecida Pereira Reis

The purpose of this work is to study the effect of heat treatments on the microstructure of the nickel-based superalloy Inconel 713C. Three different conditions were studied and the results compared: (1) as cast; (2) solid solution treatment (1179 °C/2 h) and (3) stabilization heat treatment (1179 °C/2 h plus 926 °C/16 h). Inconel 713C is normally used in the as-cast condition, an improvement in the 980 °C stress-rupture life is often obtained by a solution heat treatment. However, the material in this condition tested under high stress at 730 °C shows a marked decreased in rupture life and ductility. The mechanical resistance in creep increases in Inconel 713C by precipitation hardening phase, with γ’ (Ni3Al) formed during the heat treatments. The characterization techniques used were: chemical analysis, hardness testing, X-ray diffraction, optical microscopy and scanning electron microscopy (SEM), EDS analyzes and thermocalculation. The SEM and EDS analysis illustrated the γ, γ’ and carbides. The matrix phase (γ), has in its constitution the precipitation of the γ’ phase, in a cubic form, and in some regions, carbides were modified through the heat treatments. (M23C6-type) and boride (M3B2 type) identified with the use of the thermocalculation. The heat treatments increase the relative intensity of niobium in the carbides. The hardness test was not achieved because the material was overaged.

2019 ◽  
Vol 390 ◽  
pp. 32-40 ◽  
Author(s):  
Breno Boretti Galizoni ◽  
Antônio Augusto Couto ◽  
Danieli Aparecida Pereira Reis

The purpose of this work is to study the effect of heat treatments on the microstructure of the nickel-based superalloy Inconel 713C. Three different conditions were studied and the results compared: (1) as cast; (2) solution treatment (1,179°C/2h) and (3) stabilizing treatment (1,179°C/2h plus 926°C/16h). Inconel 713C is normally used in the as-cast condition, an improvement in the 980°C stress-rupture life is often obtained by a solution heat treatment. However, the material in this condition tested under high stress at 730°C shows a marked decreased in rupture life and ductility [1]. The mechanical resistance in creep increases in Inconel 713C by precipitation hardening phase, such γ’ (Ni3Al) formed during the heat treatments [2]. The characterization techniques used was: chemical analysis, hardness test, X-ray diffraction, optical microscope and scanning electron microscopy (SEM), EDS analyzes and thermocalculation. The heat treatments modified the dendritic structure, reducing the acicularity. The SEM and EDS analysis illustrated the γ, γ’ and carbides. The matrix phase (γ), has in its constitution the precipitation of the γ’ phase, in a cubic form, and in some regions, veins of carbides were modified with the heat treatments.


2016 ◽  
Vol 849 ◽  
pp. 570-579
Author(s):  
Qiang Huang ◽  
Jin Xia Song ◽  
Qing Li ◽  
Wei Peng Ren ◽  
Xin Guang Guan ◽  
...  

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.


2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu

The stress rupture life of DZ125 nickel-based superalloy that was prepared by directional solidification process under the temperature gradient of 500 K/cm has been studied at 900°C and 235MPa. The results showed that with the increase of directional solidification rate from 50 μm/s to 800 μm/s, the primary dendrite arm spacing reduced from 94 μm to 35.8 μm and γ' precipitates reduced and more uniformed in size. The high temperature stress rupture life of as-cast sample increased firstly and then decreased and reached its maximum at the solidification rate of 500 μm/s. The dislocation configuration of sample with refine dendritic structure after stress rupture was investigated and discovered that the dislocations in different parts of sample had different morphology and density, which indicated that the deformation of as-cast samples were uneven during high temperature stress rupture. A lot of dislocations intertwined around carbides and at the interface of γ/γ', and the dislocation networks were destroyed and the dislocations entered γ' precipitate by the way of cutting.


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.


2007 ◽  
Vol 460-461 ◽  
pp. 420-427 ◽  
Author(s):  
Jinjiang Yu ◽  
Xiaofeng Sun ◽  
Nairen Zhao ◽  
Tao Jin ◽  
Hengrong Guan ◽  
...  

1965 ◽  
Vol 87 (1) ◽  
pp. 9-20 ◽  
Author(s):  
J. C. Freche ◽  
R. L. Ashbrook ◽  
G. D. Sandrock

The high-temperature capability and workability of cobalt-tungsten alloys for aerospace applications is discussed. The average life at 1850 F and 15,000 psi of the strongest previously reported alloy, Co-25 W-1Ti-1Zr-0.4C, was doubled from 92 to 185 hr by small additions of chromium and rhenium. At 2200 F and 5000 psi, the strongest alloy, Co-25W-1Ti-1Zr-3Cr-2Re-0.4C, had a rupture life of 23 hr; the elevated-temperature rupture strength compared favorably with the strongest available conventional (high-chromium) cobalt-base alloys. Above approximately 2035 F and at reasonably high stress levels (10,000 and 15,000 psi), its stress-rupture life also exceeded those of the strongest known nickel-base alloys, including the NASA tantalum-modified alloy and SM-200. It is particularly significant that even the strongest alloys of this series were readily hot-rolled. Ingots 1/2 in. thick were reduced to 0.065-in. sheet and subsequently cold-rolled to 0.0125-in. sheet. Elongations as high as 31 percent were obtained at room temperature with annealed sheet specimens. The good ductility obtained suggests that these alloys could be fabricated into complex shapes required for various aerospace and other applications. Although the strongest alloys had a chromium content of only 3 percent, they did not oxidize catastrophically in air.


Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6157
Author(s):  
Matteo Vanzetti ◽  
Enrico Virgillito ◽  
Alberta Aversa ◽  
Diego Manfredi ◽  
Federica Bondioli ◽  
...  

Conventionally processed precipitation hardening aluminum alloys are generally treated with T6 heat treatments which are time-consuming and generally optimized for conventionally processed microstructures. Alternatively, parts produced by laser powder bed fusion (L-PBF) are characterized by unique microstructures made of very fine and metastable phases. These peculiar features require specifically optimized heat treatments. This work evaluates the effects of a short T6 heat treatment on L-PBF AlSi7Mg samples. The samples underwent a solution step of 15 min at 540 °C followed by water quenching and subsequently by an artificial aging at 170 °C for 2–8 h. The heat treated samples were characterized from a microstructural and mechanical point of view and compared with both as-built and direct aging (DA) treated samples. The results show that a 15 min solution treatment at 540 °C allows the dissolution of the very fine phases obtained during the L-PBF process; the subsequent heat treatment at 170 °C for 6 h makes it possible to obtain slightly lower tensile properties compared to those of the standard T6. With respect to the DA samples, higher elongation was achieved. These results show that this heat treatment can be of great benefit for the industry.


2013 ◽  
Vol 747-748 ◽  
pp. 659-664 ◽  
Author(s):  
Hui Li ◽  
Fu Lin Li ◽  
Shu Suo Li ◽  
Heng Zhang ◽  
Sheng Kai Gong

The influence of three different ageing treatments (R1:1100/2h,air cooling+870/32h,air cooling, R2: 870/32h,air cooling and R3: 1060/2h,air cooling+870/32h,air cooling) on stress rupture properties of Ni3Al-base single-crystal alloy IC21 was investigated. The results indicate that ageing heat treatments have obvious effects on stress rupture properties of IC21 at 850/500Mpa. After R3 ageing treatment, IC21 alloy presents the longest rupture life and the smallest ellipticity and elongation compared to those after the other two ageing treatments. Microstructure examination shows that the mean size of γ precipitate is about 0.44μm after R3 ageing heat treatment (1060/2h, ac + 870/32h, ac). Transmission electron microscope (TEM) study on the rupture samples illustrates that after R1 and R2 ageing heat treatments, the density of stacking faults increases and the length is larger compared to that after R3 heat treatment. Meanwhile the shearings of γ precipitates are more severe. The appropriate γ phase size and γ channel width after R3 treatment promote homogenous deformation by <110>{111} slip in the matrix, and facilitate the formation of finer dislocation networks on the γ/γ interface, which can restrain the shearing of γ phase by dislocations.


2018 ◽  
Vol 37 (3) ◽  
pp. 271-276
Author(s):  
P. C. Xia ◽  
K. Xie ◽  
H. Z. Cui ◽  
J. J. Yu

AbstractThe effects of heat treatment process on microstructure and properties of a nickel base superalloy are investigated. The size of γ´ phase decreases and the stress rupture life of alloy at 1100 °C/60 MPa drops with the rise of cooling rate. The hardness at room temperature also increases. The size of cuboidal γ´ precipitate and the volume of spherical γ´ precipitate increase with the rise of aging temperature. With higher aging temperature, the alloy exhibits bimodal γ´ phase. A reasonable combination of the size and volume fraction of cuboidal and spherical γ´ phase can obtain better stress rupture property at 1100 °C/60 MPa.


2007 ◽  
Vol 546-549 ◽  
pp. 1443-1446 ◽  
Author(s):  
Zhi Gang Kong ◽  
Lei Ji ◽  
Shu Suo Li ◽  
Ya Fang Han ◽  
Hui Bin Xu

The effect of heat treatment on microstructures and stress rupture property of a Ni3Al base single crystal alloy DDIC6 was studied in the present investigate. The single crystal specimens were produced by screw selection crystal method. The heat treatment for the alloy was 1300°C/10h+1120°C/4h+870°C/32h and 1300°C/10h+870°C/32h.The microstructures were examined by SEM, TEM and X-ray EDS techniques. The stress rupture tests were carried out in air by constant load creep machines under 1100°C/130MPa with the specimens size of φ5×25 mm. The experimental results showed that the as-cast large size γ′ phases entirely dissolved after 1300°C/10h, and secondary fine γ′ phases precipitated by following aging at 1120°C and 870°C for certain periods of time. The stress rupture life under 1100°C/130MPa increased from 20~30hrs for as-cast condition to 60~100hrs for heat treatment condition. The improvement of the creep resistance of the alloy may attribute to the decrement of the elements segregation at dendrite and interdendritic areas, and the proper size and distribution of γ′ phases.


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