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#### exponential creep

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Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 July 2009
DOI: 10.31399/asm.tb.fdmht.t52060001
EISBN: 978-1-62708-343-0
.../strain rate versus temperature-dependent relationships, from Kennedy Table 1.2 Creep strain/strain rate versus temperature-dependent relationships, from Kennedy Exponential temperature functions d ε/ dt = a exp(– Q/RT ) ε = a [ t exp(– Q / RT )] n d ε/ dt = aT exp(– Q / RT...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 November 2012
DOI: 10.31399/asm.tb.ffub.t53610415
EISBN: 978-1-62708-303-4
... as the amount of creep strain increases over time. Power Law Model of Steady-State Creep Rates In the intermediate-temperature regime (0.4 T m &lt; T &lt; 0.6 T m ), the creep rate varies nonlinearly with stress, as either a power function or an exponential function of stress. At stresses...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 June 2008
DOI: 10.31399/asm.tb.emea.t52240265
EISBN: 978-1-62708-251-8
...; A is the pre-exponential constant; n is a constant, usually between 3 and 10; R is the universal gas constant; and T is the absolute temperature. This equation describes the dependence of creep rate on the key variables, temperature and stress. Specific values for n and Q are associated...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2003
DOI: 10.31399/asm.tb.cfap.t69780199
EISBN: 978-1-62708-281-5
.... The exponential form of the stress function is often combined with the effect of temperature at temperatures below the glass transition temperature, T g , where the creep rate is given by: (Eq 5) ε ˙ = ε ˙ 0   e − ( Q − σ v ) / RT where ε...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 1989
DOI: 10.31399/asm.tb.dmlahtc.t60490059
EISBN: 978-1-62708-340-9
...Examples of reported values of stress exponent and activation energy for creep of steels Table 3.1. Examples of reported values of stress exponent and activation energy for creep of steels Reference System Temperature, °C n Coefficients in the low-stress region Coefficients...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 1989
DOI: 10.31399/asm.tb.dmlahtc.t60490111
EISBN: 978-1-62708-340-9
...¼Cr-1Mo steel ( Ref 38 ). Fig. 4.17. Effects of hold time and prior creep damage (0.2 and 0.6 life fractions) on cyclic endurance of 1Cr-½Mo steel ( Ref 39 ). Fig. 4.18. Effect of tensile hold time on fatigue endurance of type 316 stainless steel ( Ref 41 ). Fig. 4.19...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.tb.ssde.t52310069
EISBN: 978-1-62708-286-0
... no corrosion in the environment in which it is to be used. Good engineering practice sometimes requires that materials be selected for sufficient, but finite, service life. This is especially true for high-temperature service, for which creep and oxidation lead to limited life for all materials. The choice...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 June 2007
DOI: 10.31399/asm.tb.pmsspmp.t52000109
EISBN: 978-1-62708-312-6
..., and heating and cooling profiles, affect strength, ductility, and corrosion resistance. It also provides an extensive amount of property data – including tensile and yield strength, elongation, hardness, and creep and stress rupture measurements as well as fatigue curves – for various grades of powder metal...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 August 2005
DOI: 10.31399/asm.tb.mmfi.t69540047
EISBN: 978-1-62708-309-6
... images, diagrams, and explanations. It discusses the various factors that influence strength and ductility, including grain size, loading rate, and temperature. It also provides information on the origin of residual stresses, the concept of toughness, and the damage mechanisms associated with creep...
Book Chapter

By T. Polzin
Series: ASM Technical Books
Publisher: ASM International
Published: 01 October 2011
DOI: 10.31399/asm.tb.htpa.t53310025
EISBN: 978-1-62708-346-1
..., it is not possible to estimate the influence of the total force application time on the test result in the individual case. However, to obtain comparable hardness measurement values it is not necessary to prolong the duration time until creep has ended. For practical tests, it is certainly better to specify a small...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 August 2005
DOI: 10.31399/asm.tb.horfi.t51180197
EISBN: 978-1-62708-256-3
... size, original crack size, or effective crack size, as appropriate to the situation under consideration. crack-tip plane strain. A stress-strain eld near a crack tip that ap- proaches plane strain to the degree required by an empirical criterion. creep. Time-dependent strain occurring under stress...
Book

By Daniel P. Dennies
Series: ASM Technical Books
Publisher: ASM International
Published: 01 August 2005
DOI: 10.31399/asm.tb.horfi.9781627082563
EISBN: 978-1-62708-256-3
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 June 2008
DOI: 10.31399/asm.tb.emea.t52240017
EISBN: 978-1-62708-251-8
..., the lattice vibrations become larger, and atoms have a tendency to jump out of their normal positions, leaving a vacant lattice site behind. Fig. 2.1 Vacancy point defect. Source: Ref 1 The number of vacancies increases exponentially with temperature according to: (Eq 2.1) n v = N...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 October 2012
DOI: 10.31399/asm.tb.lmub.t53550621
EISBN: 978-1-62708-307-2
... of internal stresses left by molding and creep at service temperatures. Manufacturing cost increases exponentially with decreasing dimensional tolerance. Compatibility between materials and manufacturing processes Table 12.5 Compatibility between materials and manufacturing processes Process Cast...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2008
DOI: 10.31399/asm.tb.ssde.t52310161
EISBN: 978-1-62708-286-0
...) reduces residual stress by about 85%. Lower temperatures require exponentially longer times for the same stress relief, with times doubling for each 100 °C (180 °F) decrement as decreasing diffusion rates, which govern creep, are encountered. Cold-worked austenitic stainless steels have a markedly...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 April 2004
DOI: 10.31399/asm.tb.ps.t62440049
EISBN: 978-1-62708-352-2
... process temperatures Fig. 2.47 Effect of thickness of copper-tin intermetallic compounds in soldered joints on tensile strength at room temperature Fig. 2.48 Relationship between thickness of copper-tin intermetallic and creep rupture life of joints made to copper components using lead...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 June 2008
DOI: 10.31399/asm.tb.emea.t52240063
EISBN: 978-1-62708-251-8
... in a concentration gradient. Source: Ref 1 Diffusion plays an important role in many metallurgical processes, such as phase transformations, annealing, precipitation hardening, diffusion bonding, sintering, carburization of steels, and creep deformation. As an example, diffusion can be used to help...
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2015
DOI: 10.31399/asm.tb.cpi2.t55030380
EISBN: 978-1-62708-282-2
... in a coating that extend through to the substrate or underlying surface. crazing. A network of checks or cracks appearing on the surface. creep. Time-dependent strain occurring under stress. The creep strain occurring at a diminishing rate is called primary creep; that occurring at a minimum and almost...
Book

Series: ASM Technical Books
Publisher: ASM International
Published: 01 December 2015
DOI: 10.31399/asm.tb.cpi2.9781627082822
EISBN: 978-1-62708-282-2
Book Chapter

Series: ASM Technical Books
Publisher: ASM International
Published: 01 August 2005
DOI: 10.31399/asm.tb.pb.t51230001
EISBN: 978-1-62708-351-5
... [1996] Fig. 1.22 Calculated time for molten tin and copper to flow up a perfectly wetted capillary [ Nicholas 1989 ] Fig. 1.20 The concentration of a solid metal in a liquid metal wetted by it changes in an inverse exponential manner with respect to time and is limited...