scholarly journals The Effect of Boron and Zirconium on Microstructure and Stress-Rupture Life of Nickel-based Superalloy ATI 718Plus

10.30544/72 ◽  
2015 ◽  
Vol 21 (4) ◽  
pp. 259-268 ◽  
Author(s):  
Seyed Ali Hosseini ◽  
Seyed Mehdi Abbasi ◽  
Karim Zanganeh Madar
Keyword(s):  
Rupture Life ◽  
Melting Furnace ◽  
Stress Rupture ◽  
Vacuum Induction Melting ◽  
High Temperature Strength ◽  
Induction Melting ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy ◽  
Δ Phase

The effects of boron and zirconium on the microstructure, hardness and stressrupture life of the nickel-based superalloy ATI 718Plus were investigated in this study. Four alloys with different percentages of boron (0.005-0.01 wt.%) and zirconium (0-0.1 wt%) were cast through a vacuum induction melting furnace and then were rolled. The microstructural studies indicated an increased percentage of δ phase, carbide precipitates and twins in the presence of zirconium. The percentage of carbide (boron carbide) precipitates was increased and the solidification range of the alloy was decreased in the presence of boron in the composition. Furthermore, the results obtained from the hardness and stress-rupture tests showed the significant role of both elements in increasing hardness and improved rupture life of the alloy. The maximum rupture life was observed in the alloy which contained the highest percentages of boron and zirconium in its composition. This can be attributed mainly to the increased percentage of δ phase on grain boundaries and their enhanced high-temperature strength.

High Temperature Rupture Life of Nickel-Based Superalloy under Directional Solidification with High Temperature Gradient

2017 ◽  
Vol 898 ◽  
pp. 422-429 ◽  
Author(s):  
Wei Guo Zhang ◽  
Zhi Jie Liu ◽  
Song Ke Feng ◽  
Fu Zeng Yang ◽  
Lin Liu
Keyword(s):  
High Temperature ◽  
Temperature Gradient ◽  
Directional Solidification ◽  
Temperature Stress ◽  
Solidification Rate ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Stress ◽  
Stress Rupture Life ◽  
Nickel Based Superalloy

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.

Role of Rhenium in Single Crystal Ni-Based Superalloys

2010 ◽  
Vol 638-642 ◽  
pp. 2257-2262 ◽  
Author(s):  
Tao Jin ◽  
Wen Zhen Wang ◽  
Xiao Feng Sun ◽  
Zhuang Qi Hu
Keyword(s):  
Single Crystal ◽  
Rupture Life ◽  
Solution Process ◽  
Stress Rupture ◽  
Nominal Composition ◽  
Stress Rupture Life ◽  
Dislocation Configuration ◽  
Rhenium Addition ◽  
Rhenium Content

The effect of rhenium on the microstructure and mechanical properties of single crystal superalloys with a nominal composition of Ni-3Cr-12Co-1Mo-6W-6Al-8Ta-0.1Hf-(0, 2, 4) Re has been studied. With the rise of rhenium content, the size of as-cast  particles becomes smaller. Rhenium addition elevates the incipient melting temperature and slows down the solid solution process. Even after 2000h prolonged aging both at 950°C and 1050°C, no topologically close-packed phase precipitation is found in the three alloys with Re content up to 4%. Re retards the  coarsening and is beneficial to improving the stress rupture life. The deformation mechanisms together with the dislocation configuration have been studied and discussed.

scholarly journals Influence of Phosphorus Addition on the Stress Rupture Properties of Direct Aged IN706 Superalloy

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 641
Author(s):  
Sha Zhang ◽  
Anwen Zhang ◽  
Chaochao Xue ◽  
Dan Jia ◽  
Weiwei Zhang ◽  
...  
Keyword(s):  
Rupture Life ◽  
Stress Rupture ◽  
Phosphorus Addition ◽  
Stress Rupture Life ◽  
P Concentration ◽  
Stress Rupture Properties ◽  
Rupture Properties ◽  
The Relationship ◽  
P Addition

This study investigated the influence of phosphorus (P) addition on the stress rupture properties of direct aged IN706 superalloy. The results showed that P slightly improved the stress rupture life of the superalloy when added in the range between 0.002% and 0.008%; however, it significantly reduced the stress rupture life when added in the range between 0.013% and 0.017%. Microstructure characterization indicated that the precipitation of γ′, γ″, and η phases was not significantly affected by the addition of P. Phosphides precipitated in the alloy containing 0.017% P after aging at 980 °C for 10 min. Compared to a similar study previously made on IN706 superalloy, it was found that the optimum P concentration in the as-solutioned state for improving the stress rupture properties was not definite. Furthermore, the relationship between the amount of P segregated at the grain boundary and the role of P on the stress rupture properties was discussed.

Peritectic Reaction of High Nb and W Pentatomic TiAl-Based Alloy

2011 ◽  
Vol 335-336 ◽  
pp. 831-835
Author(s):  
Hong Liang Sun ◽  
Cai Sun ◽  
Ze Wen Huang ◽  
De Gui Zhu
Keyword(s):  
Grain Size ◽  
Peritectic Reaction ◽  
Room Temperature ◽  
Aluminum Content ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Temperature Strength ◽  
Stress Rupture Life ◽  
Correlation Relationship ◽  
Room Temperature Strength

The effect of different aluminum content on peritectic reaction and mechanical properties of pentatomic TiAl-based alloy was investigated. The results indicate that the grain size gradually increase with increasing content of aluminum and addition 45.7% aluminum in TiAl-based alloy results in that the peritectic reaction can increase grain size greatly, respectively. The content of aluminum can increase the room temperature strength, high temperature strength but peritectic reaction can effectively reduce tensile strength. Aluminum content has a little effect on the ductility. The stress rupture life has positive correlation relationship with the content of aluminum.

Morphology, Distribution and Identification of Micro-Constituents Along Grain Boundaries in Nickel-Base Alloys

1973 ◽  
Vol 31 ◽  
pp. 176-177
Author(s):  
D. E. Fornwalt ◽  
A. R. Geary ◽  
B. H. Kear
Keyword(s):  
Electron Microscope ◽  
Grain Boundaries ◽  
Volume Fraction ◽  
Rupture Life ◽  
Stress Rupture ◽  
High Volume ◽  
Precipitate Morphology ◽  
Stress Rupture Life ◽  
Nickel Base ◽  
Scanning Electron

A systematic study has been made of the effects of various heat treatments on the microstructures of several experimental high volume fraction γ’ precipitation hardened nickel-base alloys, after doping with ∼2 w/o Hf so as to improve the stress rupture life and ductility. The most significant microstructural chan§e brought about by prolonged aging at temperatures in the range 1600°-1900°F was the decoration of grain boundaries with precipitate particles.Precipitation along the grain boundaries was first detected by optical microscopy, but it was necessary to use the scanning electron microscope to reveal the details of the precipitate morphology. Figure 1(a) shows the grain boundary precipitates in relief, after partial dissolution of the surrounding γ + γ’ matrix.

Synthesis and Forming of Titanium Matrix Composites by Casting Route

2007 ◽  
Vol 334-335 ◽  
pp. 297-300
Author(s):  
Si Young Sung ◽  
Bong Jae Choi ◽  
Young Jig Kim
Keyword(s):  
Electron Microscopy ◽  
Melting Furnace ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Matrix Composites ◽  
Titanium Matrix ◽  
Titanium Matrix Composites ◽  
Electron Probe Micro Analyzer ◽  
Transmission Electron

The aim of this study is to evaluated the possibility of the in-situ synthesized (TiC+TiB) reinforced titanium matrix composites (TMCs) for the application of structural materials. In-situ synthesis and casting of TMCs were carried out in a vacuum induction melting furnace with Ti and B4C. The synthesized TMCs were characterized using scanning electron microscopy, an electron probe micro-analyzer and transmission electron microscopy, and evaluated through thermodynamic calculations. The spherical TiC plus needle-like and large, many-angled facet TiB reinforced TMCs can be synthesized with Ti and B4C by a melting route.

Mutation in TCP phases and superior stress rupture life led by W/Mo ratio in Ni-based single crystal superalloys

2022 ◽  
pp. 131656
Author(s):  
Jinbin Chen ◽  
Jingyang Chen ◽  
Qinjia Wang ◽  
Yidong Wu ◽  
Qing Li ◽  
...  
Keyword(s):  
Single Crystal ◽  
Rupture Life ◽  
Stress Rupture ◽  
Stress Rupture Life ◽  
Tcp Phases

Cycling Stability Performance of La0.75Mg0.25Ni3.5Si0.10 Hydrogen Storage Alloy in Discharge–Charge System

2014 ◽  
Vol 13 (05n06) ◽  
pp. 1460003
Author(s):  
Zhaojiang Liu ◽  
Lei Huang ◽  
Qi Wan ◽  
Xu Li ◽  
Ma Guang ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Electrochemical Properties ◽  
Melting Furnace ◽  
Test System ◽  
Cycling Stability ◽  
Hydrogen Storage Alloy ◽  
Vacuum Induction Melting ◽  
Induction Melting ◽  
Stability Performance ◽  
Charge Discharge

La 0.75 Mg 0.25 Ni 3.5 Si 0.10 hydrogen storage alloy was prepared by vacuum induction melting furnace and subsequently heated treatment at 940°C for 8 h and cooled to room temperature in the oven. The electrochemical properties of La 0.75 Mg 0.25 Ni 3.5 Si 0.10 compound were measured by LAND CT2001A battery test system. The morphologies of the samples were characterized by scanning electron microscopy (SEM). The surface state of samples was analyzed by X-ray photoelectron spectroscopy (XPS). It was found that the charge–discharge rate plays the key impact on the cycling stability of the alloy. During the cycle test, the prepared La 0.75 Mg 0.25 Ni 3.5 Si 0.10 compound presented an excellent capacity retention at the charge–discharge of 1 C while the capacity of sample declined rapidly at 0.2 C. The excellent cycling stability performance of La 0.75 Mg 0.25 Ni 3.5 Si 0.10 electrode at 1 C could be attributed to the less powder and less oxidation of surface effective active elements. The pulverization inevitably leads to the separation of the part of the cracking alloy and the electrode, resulting in reduction of the effective active substance and increasing attenuation of the capacity per cycle. In addition, on the analysis of the different cut-off potential effects on the electrode, it was found that the La 0.75 Mg 0.25 Ni 3.5 Si 0.10 electrode shows good comprehensive electrochemical properties at 1 C cut-off 0.6–0.7 V. During charging, heavy overcharge will not be conducive to cycling stability performance during the charging test.

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.

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