NiCr-CrAl Coating for Ni3Al Base Alloy IC6AE

2007 ◽  
Vol 546-549 ◽  
pp. 1467-1470
Author(s):  
Shu Suo Li ◽  
Chun Xiao Zhang ◽  
Yong Wang Kang ◽  
Ya Fang Han
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Hot Corrosion ◽  
Base Alloy ◽  
Rupture Life ◽  
Stress Rupture ◽  
Tensile Tests ◽  
Stress Rupture Life ◽  
Obvious Effect ◽  
Resistance Tests

The effect of NiCr-CrAl coating on the microstructure, oxidation and corrosion resistance, as well as mechanical properties of Ni3Al base alloy IC6AE has been studied in the present investigation. NiCr-CrAl coating for alloy IC6AE was prepared by the powder pack cementation method. The oxidation resistance tests were carried out under the condition of 1050°C/100h, while the hot corrosion resistance tests were under 900°C/100h. The tensile tests at the room temperature and the stress rupture life tests under 1050°C/90Mpa have been also conducted. The experimental results showed that NiCr-CrAl as-coated specimens had excellent oxidation and hot corrosion resistance compared with the alloy IC6AE blank specimens, and NiCr-CrAl coating has no obvious effect on the mechanical properties of alloy IC6AE. It may be concluded that NiCr-CrAl coating is suitable for the alloy IC6AE.

Effects of Long-Term Aging at 1070°C on Microstructure and Mechanical Properties of Ni3Al-Base Alloy IC6E

2010 ◽  
Vol 650 ◽  
pp. 205-209 ◽  
Author(s):  
Ming Li ◽  
Jin Xia Song ◽  
Shu Suo Li ◽  
Ya Fang Han
Keyword(s):  
Mechanical Properties ◽  
Grain Boundaries ◽  
Base Alloy ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Microstructure And Mechanical Properties ◽  
Stress Rupture Properties ◽  
Essential Change

The effect of long-term aging at 1070°C on microstructure and mechanical properties of Ni3Al-base equiaxed superalloy IC6E was investigated. The microstructure change during aging for periods of 100 to 1500h was examined by SEM . Results showed that alloy IC6E underwent following microstructure changes during aging: γ' phases coalesced and grew, γ phases became disconnected and coarsened, the content of Mo (the solution-hardening element of γ and γ' phases) in γ' phases decreased, Y-NiMo phases precipitated from γ phases both at grain boundaries and within grains, and γ' bands and large γ phases emerged along grain boundaries. The tensile and stress rupture properties after aging were determined. The results showed that the yield strength of alloy IC6E at room temperature decreased obviously after aging for 100 h, and reduced slowly during further aging. The stress rupture life under 1070°C, 80MPa also had no essential change during aging.

Effect of Microcast-X Fine Grain Casting on the Microstructure and Mechanical Properties of K492M Alloy at 760°C

2016 ◽  
Vol 849 ◽  
pp. 549-556
Author(s):  
Pin Pin Hu ◽  
Qi Dong Gai ◽  
Qing Li ◽  
Xin Tang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Rupture Life ◽  
Stress Rupture ◽  
Casting Alloy ◽  
Stress Rupture Life ◽  
Casting Technique ◽  
Conventional Casting ◽  
Fine Grain

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.

Stress Rupture Behavior of Disk Superalloys Exposed to Low-Temperature Hot Corrosion Environment

2020 ◽  
Author(s):  
Dipankar Dua ◽  
Mohammad Khajavi ◽  
Gary White ◽  
Deepak Thirumurthy ◽  
Jaskirat Singh
Keyword(s):  
Low Temperature ◽  
Hot Corrosion ◽  
Inconel 718 ◽  
Gas Turbines ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Corrosive Environments ◽  
The Impact ◽  
Temperature Surface

Abstract Siemens Energy has a large fleet of aero-derivative gas turbines. The performance and durability of these power turbines largely depend on the capability of hot section components to resist high-temperature surface attacks and to maintain their mechanical properties. Hot corrosion attack occurs due to exposure of turbine components to sulfur-bearing fuels/air together with other corrosive compounds during turbine operation. This paper investigates the impact of low-temperature hot corrosion on the stress rupture of commonly used gas turbine disk alloys, including Inconel 718, Incoloy 901, and A-286. The results indicate that Inconel 718 and Incoloy 901 maintain their creep strength advantage over A-286 in a low-temperature hot corrosion inducing environment at 1100°F. All three materials exhibited an equivalent life reduction in the corrosive environments at 1100°F. Moreover, the results demonstrate that the stress-rupture life of materials in hot-corrosion environments depends on the combined and cumulative effects of corrosion-resistant and hardening elements.

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 ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Cooling Rate ◽  
Room Temperature ◽  
Rupture Life ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Microstructures And Mechanical Properties

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.

Heat Treated Microstructure and Mechanical Properties of K492M Alloy

2014 ◽  
Vol 788 ◽  
pp. 493-497
Author(s):  
Xiang Hui Li ◽  
Lian Li ◽  
Xin Tang ◽  
Qi Dong Gai
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Interdendritic Region ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Stress Rupture Properties ◽  
Heat Treated ◽  
Columnar Grain ◽  
Rupture Properties

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.

Effect of Hot Isostatic Pressing on Microstructures and Mechanical Properties of IN738LC Superalloy

2017 ◽  
Vol 898 ◽  
pp. 401-406
Author(s):  
Qun Gong He ◽  
Jun Liu ◽  
Lin Xu Li ◽  
Zhen Huan Gao ◽  
Xiao Yan Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Impact Toughness ◽  
Rupture Life ◽  
Hot Isostatic Pressing ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Isostatic Pressing ◽  
Microstructures And Mechanical Properties ◽  
The Impact

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.

The Role of Solidification Rate on Fiber Distribution and Mechanical Properties of a Directionally Solidified Nickel Base-Tac Eutectic

1981 ◽  
Vol 12 ◽  
Author(s):  
John L. Walter
Keyword(s):  
Base Alloy ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Strength ◽  
Directionally Solidified ◽  
Fiber Density ◽  
Alloy Matrix ◽  
Stress Rupture Life ◽  
Nickel Base

ABSTRACTA nickel base-TaC eutectic alloy consisting of 53 wt % Ni, 11 W, 3 Re, 5 Co, 3 Mo, 2 Al, 21.67 Ta and 1.33 C was directionally solidified at rates from 0.32 to 3.8 cm/hr. Samples were taken from the regions of aligned TaC fibers and tested in tension at 1000°C and in stress-rupture. The fiber density increased from 1×106 fibers/cm2 at 0.32 cm/hr to 27×106 fibers/cm2 at 3.8 cm/hr. The stress-rupture life at 927°C and 275.6 MPa ranged from 4 hrs for samples solidified at 0.32 cm/hr to 4187 hrs for the sample solidified at 2.54 cm/hr at which time the test was terminated. Examination, by transmission electron microscopy, of the samples tested at 1000°C in tension, to just the beginning of fiber breakage, revealed a change in the mode of deformation of the nickel-base alloy matrix with increasing fiber density. It was also seen that the TaC fibers deformed by two mechanisms; by slip and by the formation of stacking faults.It appears that tailoring the alloy composition to allow for higher solidification rates may be a more effective strengthener than alloying the matrix for high strength.

Recycled Applications of a Single Crystal Superalloy

2011 ◽  
Vol 239-242 ◽  
pp. 1422-1427 ◽  
Author(s):  
Jin Jiang Yu ◽  
Xiao Feng Sun ◽  
Jiang Xin Lou ◽  
Hai Xia Lang ◽  
Heng Rong Guan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rupture Life ◽  
Stress Rupture ◽  
Ceramic Filter ◽  
Recycle Material ◽  
Stress Rupture Life ◽  
Stress Rupture Property ◽  
Foam Ceramic ◽  
Foam Ceramic Filter ◽  
Recycled Material

The effects of application of recycled scraps on the composition, microstructure and mechanical properties of SRR99 alloy were studied. The compositions of recycle master alloy are similar to that of the fresh alloy. However, nitrogen content, the size and amount of microporosity increase significantly with the recycle material proportion. Granular, lamellar and strip-like MC particles mainly represent in the interdendritic regions of the revert alloy. With the addition of the recycled material proportion, the amount of the granular ones rapidly drop and the lamellar ones gently enhance. The stress rupture life decline with the addition of the recycled material proportion. The oxide and sulphide inclusions in revert superalloy can be effectively captured and removed by a foam ceramic filter so that the tensile and stress rupture property has been significantly improved.

Influences of W and Al on the Microstructure and Stress-Rupture Property of Re-Free Ni-Based Single Crystal Superalloys

2017 ◽  
Vol 898 ◽  
pp. 492-497
Author(s):  
Jing Yang Chen ◽  
Qing Li ◽  
Ming Jun Zhang ◽  
Xin Tang ◽  
Cheng Bo Xiao
Keyword(s):  
Single Crystal ◽  
Volume Fraction ◽  
Base Alloy ◽  
Rupture Life ◽  
Solidus Temperature ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Stress Rupture Property ◽  
Matrix Channel ◽  
Liquidus Temperatures

The influence of W and Al on the solidus and liquidus temperatures, microstructure and stress-rupture property at 980 °C/250 MPa was investigated in three Re-free experimental Ni-based single crystal superalloys. The results indicated that the solidus temperature increased for 14.0 °C and 9.8 °C by adding 0.84 wt.% W only and adding 0.45 wt.% Al and 0.44 wt.% W to the base alloy, respectively. The γ′ morphology changed from nearly cuboidal in the base alloy to cuboidal by adding 0.45 wt.% Al and 0.44 wt.% W. The volume fraction of γ′ precipitates increased, while the γ channel width decreased after adding Al and W. The additions of Al and W improved the stress-rupture life at 980 °C/250 MPa because of higher γ′ volume fraction, narrower γ matrix channel and more complete rafting structure.

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