Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy

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. 401-406
Author(s):  
Qun Gong He ◽  
Jun Liu ◽  
Lin Xu Li ◽  
Zhen Huan Gao ◽  
Xiao Yan Shi ◽  
...  

The microstructures and mechanical properties of IN738LC superalloy made by investment castings followed by Hot Isostatic Pressing (HIP) treatment have been investigated. The results revealed that after HIP treatment, the microporosities have been almost removed and the density rose by 0.21%. The eutectic size became smaller and the fraction decreased. The γ' phase was more regular and also increased in size, while a large number of secondary γ' phase appeared. With HIP treatment, the impact toughness increased from 5.0J ~ 7.0J to 8J ~ 9J and tensile strength at 200°C ~ 800°C was improved by approximately 3.2%~19.7%. In addition, the ductility and the stress rupture life have also been greatly improved as well.


2006 ◽  
Vol 114 ◽  
pp. 91-96 ◽  
Author(s):  
Maxim Yu. Murashkin ◽  
M.V. Markushev ◽  
Julia Ivanisenko ◽  
Ruslan Valiev

The effects of equal channel angular pressing (ECAP), further heat treatment and rolling on the structure and room temperature mechanical properties of the commercial aluminum alloys 6061 (Al-0.9Mg-0.7Si) and 1560 (Al-6.5Mg-0.6Mn) were investigated. It has been shown that the strength of the alloys after ECAP is higher than that achieved after conventional processing. Prior ECAP solution treatment and post-ECAP ageing can additionally increase the strength of the 6061 alloy. Under optimal ageing conditions a yield strength (YS) of 434 MPa and am ultimate tensile strength (UTS) of 470 MPa were obtained for the alloy. Additional cold rolling leads to a YS and UTS of 475 and 500 MPa with 8% elongation. It was found that the post-ECAP isothermal rolling of the 1560 alloy resulted in the formation of a nano-fibred structure and a tensile strength (YS = 540 MPa and UTS = 635 MPa) that has never previously been observed in commercial non-heat treatable alloys.


2016 ◽  
Vol 849 ◽  
pp. 549-556
Author(s):  
Pin Pin Hu ◽  
Qi Dong Gai ◽  
Qing Li ◽  
Xin Tang

The effect of Microcast-X fine grain casting on the microstructure and mechnical property K492M alloy at 760°C of was investigated. The results indicated that Microcast-X fine grain casting decreased grain size and dendrite space of γ′ phase and γ/γ′ eutectic. In addition, the element segregation decreased significantly compared to conventional casting technique. Also, the size and distribution of MC carbide were improved. By Microcast-X fine grain casting, the tensile strength increased from 934MPa of conventional casting alloy to 1089MPa and the elongation increased from 1.9% to 5.7%. In addition, the stress-rupture life increased from 28.8h of conventional casting alloy to 72.5h. And the fracture mechanism for the alloys by Microcast-X fine grain casting is trans-granular fracture toughness.


2017 ◽  
Vol 898 ◽  
pp. 476-479
Author(s):  
Jin Xia Yang ◽  
Yuan Sun ◽  
Dong Ling Zhou

The effects of HIP process on microstructure and mechanical properties of IN792 cast superalloy were studied. The results showed that HIP process produced more uniform and finer cubic γ′ than standard heat treatment. The difference of the mechanical properties should be caused by the microstructure changes. HIP process leads the homogeneous distribution of γ′ at dendritic arm and interdendritic area, and improved UTS and YS of tested alloy at 550°C. However, it played no role in increasing UTS and YS at room temperature and stress-rupture lives of 760°C/662MPa and decreased stress-rupture lives of 982°C/186MPa.


2013 ◽  
Vol 690-693 ◽  
pp. 44-48
Author(s):  
Feng Wang ◽  
Zhi Wang ◽  
Zheng Liu ◽  
Ping Li Mao

In this paper, developed a non-aluminum die casting magnesium alloys were studied based on Mg-xGd-Y-Zr(x=6, 8, 12 wt.%)alloys in cold chamber press. The microstructures and mechanical properties of die casting GWK alloys have been investigated using OM, SEM, XRD, EDS and mechanical property test. The experimental results show that with increasing Gd content of Mg-xGd-Y-Zr alloys, the tensile strength increase, but elongation decrease. In particular, die casting GWK alloys after short-term and low-temperature solid solution treatment (T4) have a small variation in grain size and more uniform microstructures, and the second phases distribute at the grain boundaries in form of discontinuous rod shape or granule shape, which result in an obvious improvement in tensile mechanical properties of alloys. The Mg-12Gd-3Y-0.5Zr die casting alloy exhibit maximum tensile strength after solution heat treatment, and the value is 269MPa at room temperature. The effect of solution heat treatment on die casting Mg-xGd-Y-Zr alloys was also discussed.


2012 ◽  
Vol 535-537 ◽  
pp. 768-771
Author(s):  
Min Wang ◽  
Hong Xin ◽  
Shu Lan Guo

Abstract:The microstructures and mechanical properties of 22Mn2SiVBS steel after austenitizing at 1280°C and then cooling in air and piled up after rolled were studied in this paper .the results show that when 22Mn2SiVBS steel cooling in air it can obtain the fine grain granular bainte and remain austenite,and piled up after rolled it can obtain granular bainte and proeutectoid ferrite. After heat treatment the strength and hardness is higher than the sample piled up after rolled, but the toughness is lower.


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

2014 ◽  
Vol 788 ◽  
pp. 493-497
Author(s):  
Xiang Hui Li ◽  
Lian Li ◽  
Xin Tang ◽  
Qi Dong Gai

The microstructure, tensile and stress rupture properties of K492Malloy have been investigated in the present study. The results revealed that γ matrix, γ′ phase, carbide and eutectic in the interdendritic region within grain interior and along grain boundary were observed after solidification. After heat treatment, γ' precipitates with two obviously distinct size existed in the dendrite core and interdendritic region, respectively. Meanwhile, the chain-like (W, Mo)6C and Cr23C6carbides precipitated along grain boundary. The investigation of mechanical properties suggested that the tensile strength was initially increased but then decreased with increasing the temperature from 25oC to 760oC. The stress rupture life was 68.2h and 35.8h at 760oC / 655MPa and 870oC / 365MP, respectively. The columnar grain and carbide along grain boundary resulted in intergranular brittle fracture in both test conditions. As a result, the elongation under the conditions of 760oC/655MPa and 870oC/365MP was 1.5% and 1.4%, respectively.


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 561-565 ◽  
pp. 415-418 ◽  
Author(s):  
Zheng Dong Li ◽  
Guo Qing Zhang ◽  
Zhou Li ◽  
Wen Yong Xu ◽  
Rui Ping Yao ◽  
...  

Sound billets were produced at BIAM with a twin-scanning spray forming facility. Microstructure and mechanical properties of In718 alloy produced with this technology were examined. Both tensile strength and stress rupture properties are excellent with the rupture life even doubled after received a direct aging heat treatment.


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