Some Problems in High-Temperature Bearing Materials

1968 ◽  
Vol 90 (4) ◽  
pp. 841-845
Author(s):  
N. S. Stoloff
Keyword(s):  
High Temperature ◽  
Creep Strength ◽  
Radial Growth ◽  
Hastelloy X ◽  
Surface Stability ◽  
Dimensional Changes ◽  
Long Time ◽  
Bearing Materials ◽  
Nickel Base ◽  
Static Conditions

Bearings which are lubricated by process fluids are being considered for application at temperatures exceeding 1000 deg F. Although under static conditions, nickel-base alloys offer an excellent combination of strength and surface stability, these alloys may change dimensions during long-time bearing applications. It is shown that if creep strength is inadequate, high shaft speeds can lead to significant radial growth. Dimensional stability is also affected by precipitation. A detailed study of Hastelloy X heated in the temperature range 1100–1400 deg F reveals that precipitation occurs even after many hundreds of hours exposure, resulting in dimensional changes of up to 3 microin. per hr of exposure. Means of alleviating these problems are discussed.

Measurement of Long Range Order in the γ’ Phase of Nickel-Base Superalloys

1969 ◽  
Vol 13 ◽  
pp. 598-608
Author(s):  
J.R. Mihalisin
Keyword(s):  
High Temperature ◽  
Long Range ◽  
Range Order ◽  
Long Range Order ◽  
X Ray Diffraction ◽  
High Temperature Heat Treatment ◽  
Heat Treated ◽  
Temperature Heat ◽  
Long Time ◽  
Nickel Base

The long range order parameter (S) has been measured at room- temperature on the γ’ phase extracted from IN-731 and alloys 713C and 713LC by x-ray diffraction techniques. Measurements were obtained from specimens of IN-731 and alloy 713LC in the as-cast condition and after long time rupture testing. The alloy 713 c specimens were in the as-cast and high temperature heat treated conditions.It was found that long range order in the γ’ phase of IN-731 and alloy 713LC was changed very little after long time rupture testing, and after high temperature heat treatment in the case of alloy 713C.

scholarly journals Synthesis of MIL-100(Fe) at Low Temperature and Atmospheric Pressure

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Jing Shi ◽  
Shengtao Hei ◽  
Huanhuan Liu ◽  
Yanghe Fu ◽  
Fumin Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Atmospheric Pressure ◽  
Structural Characteristics ◽  
Metal Organic Framework ◽  
Potential Applications ◽  
Long Time ◽  
Metal Organic ◽  
Static Conditions ◽  
Mesoporous Metal

MIL-100(Fe), a mesoporous metal-organic framework (MOF), has a large BET specific surface area and pore volume with the presence of a significant amount of accessible Lewis acid metal sites upon dehydration. The structural characteristics of MIL-100(Fe) make it a good candidate for potential applications in gas storage, separation, and heterogeneous catalysis. Mainly, this MOF is obtained by the hydrothermal synthesis in a Teflon-lined autoclave at high temperature (>150°C) under static conditions. However, this method has several disadvantages such as high temperature, high (autogenous) pressure, long time, and comparable low MOF yield. Therefore, development of a facile method for synthesis of MIL-100(Fe) is vitally important for fundamental understanding and practical application. Herein, MIL-100(Fe) is synthesized by a facile low-temperature (<100°C) synthesis route at atmospheric pressure by reaction of metallic iron and trimesic acid in water. Due to our synthesis is conducted with agitation, higher MOF yield (>90%) still could be achieved, suggesting that this simple and energy saving method has the potential to be used practically.

scholarly journals The Role of Small Amounts of Magnesium in Nickel-Base and Iron-Nickel-Base Superalloys after High Temperature Long Time Exposures

1984 ◽  
Author(s):  
G. Chen ◽  
D. Wang ◽  
Z. Xu ◽  
J. Fu ◽  
K. Ni ◽  
...  
Keyword(s):  
High Temperature ◽  
Long Time ◽  
Iron Nickel ◽  
Nickel Base Superalloys ◽  
Nickel Base

RMI 6Al-2Sn-4Zr-2Mo

Alloy Digest ◽  
1981 ◽  
Vol 30 (8) ◽  
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Creep Strength ◽  
Temperature Stability ◽  
Heat Treating ◽  
Jet Engines ◽  
High Temperature Stability ◽  
Beta Titanium Alloy ◽  
Beta Titanium ◽  
Long Time

Abstract RMI 6Al-2Sn-4Zr-2Mo is an alpha-beta titanium alloy that provides a tensile strength of 130,000 psi in the mill-annealed condition. It is characterized by an excellent combination of tensile strength, creep strength, toughness and high-temperature stability that makes it suitable for service to 1050 F. It is recommended for use where high creep strength is required, as in components for jet engines. It has outstanding advantages for long-time use at temperature to 800 F. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-83. Producer or source: RMI Company.

scholarly journals Corrosion Phenomena of High Temperature Alloys by Helium Impurities in the Primary Coolant of HTGR

2021 ◽  
Vol 2048 (1) ◽  
pp. 012018
Author(s):  
Q Wang ◽  
W Zheng ◽  
H Yin ◽  
S Li ◽  
X He ◽  
...  
Keyword(s):  
High Temperature ◽  
Base Alloy ◽  
Trace Impurities ◽  
Protective Oxide ◽  
Primary Coolant ◽  
High Temperature Alloys ◽  
Carbon Transfer ◽  
Long Time ◽  
Inconel 617 ◽  
Nickel Base

Abstract The primary coolant circuit of the high temperature gas-cooled reactor (HTGR) contains trace impurities. A nickel base alloy would corrode when exposed to an atmosphere at a high temperature and for a long time. The protective oxide scale formed by chromium is an important factor to prevent severe corrosion of high temperature alloys. Corrosion tests were conducted on Inconel 617, Incoloy 800H, Hastelloy X, and T-22, which are commonly used in the steam generator of HTGR. The alloys were exposed to helium with trace impurities for 48 hours at 950°C. The corrosion results were analyzed by weighing, scanning electron microscopy (SEM) and electron probe microanalyzer (EPMA). All the four alloys formed oxide scales in this atmosphere, but they differ in the capacity to resist corrosion. Therefore, the carbon transfer phenomenon observed in this experiment varies for the different alloys. In addition, for Cr in Inconel617, the expected depletion phenomenon near the corrosion layer occurred, which is consistent with the results from theoretical analysis.

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Microstructural characterization of plasma-processed Ti-Al metal matrix composites

1989 ◽  
Vol 47 ◽  
pp. 552-553
Author(s):  
M. G. Burke ◽  
M. N. Gungor ◽  
M. A. Burke
Keyword(s):  
High Temperature ◽  
Titanium Aluminide ◽  
Plasma Processing ◽  
Microstructural Characterization ◽  
High Temperature Strength ◽  
Matrix Composites ◽  
Intermetallic Matrix ◽  
Long Time ◽  
Strength And Stiffness ◽  
Intermetallic Matrix Composites

Intermetallic matrix composites are candidates for ultrahigh temperature service when light weight and high temperature strength and stiffness are required. Recent efforts to produce intermetallic matrix composites have focused on the titanium aluminide (TiAl) system with various ceramic reinforcements. In order to optimize the composition and processing of these composites it is necessary to evaluate the range of structures that can be produced in these materials and to identify the characteristics of the optimum structures. Normally, TiAl materials are difficult to process and, thus, examination of a suitable range of structures would not be feasible. However, plasma processing offers a novel method for producing composites from difficult to process component materials. By melting one or more of the component materials in a plasma and controlling deposition onto a cooled substrate, a range of structures can be produced and the method is highly suited to examining experimental composite systems. Moreover, because plasma processing involves rapid melting and very rapid cooling can be induced in the deposited composite, it is expected that processing method can avoid some of the problems, such as interfacial degradation, that are associated with the relatively long time, high temperature exposures that are induced by conventional processing methods.

Physicochemical properties and creep strength of a single crystal of nickel-base superalloy containing rhenium and ruthenium

2010 ◽  
Vol 101 (5) ◽  
pp. 594-600 ◽  
Author(s):  
Nikolay V. Petrushin ◽  
Igor L. Svetlov ◽  
Andrey I. Samoylov ◽  
Galina I. Morozova
Keyword(s):  
Physicochemical Properties ◽  
Single Crystal ◽  
Creep Strength ◽  
Nickel Base Superalloy ◽  
Nickel Base ◽  
Base Superalloy

ALTEMP HX

Alloy Digest ◽  
1993 ◽  
Vol 42 (10) ◽  
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract ALTEMP HX is an austenitic nickel-base alloy designed for outstanding oxidation and strength at high temperatures. The alloy is solid-solution strengthened. Applications include uses in the aerospace, heat treatment and petrochemical markets. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, and joining. Filing Code: Ni-442. Producer or source: Allegheny Ludlum Corporation.

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