Abstract
Recently early approaches based on creep equations have been revived to describe the creep deformation and fracture. In this report creep equations of the type {epsilon}{sub 1}={beta}{sub 1}t{sup 1/3}, {epsilon}{sub 2}={beta}{sub 2}t and {epsilon}{sub 3}={beta}{sub 3}t{sup 3} where {epsilon}{sub 1}, {epsilon}{sub 2}, {epsilon}{sub 3} are the creep strains in the primary, secondary and tertiary stages, {beta}{sub i} the respective coefficients and t the time, are used to envelope the creep strain data on the log-log plot of creep strain versus time. Based on this approach the creep behaviour of the following engineering materials has been analysed: X10 NiCrAlTi 32 20 (Alloy 800 H), 13 CrMo 4 4 (1 Cr-0.5 Mo) steel in both new and service exposed conditions, 14 CrMoV 6 3 (0.5 Cr-0.5 Mo-0.25 V) steel a Ni-base superalloy. The analysis leads to an important modification of the Dobes-Milicka rule, namely, that the minimum creep rate {epsilon}{sub min} and the rupture time t{sub r} are related not only to the creep rupture strain {epsilon}{sub r} but also to the creep strain at the end of the second stage {epsilon}{sub 23}, given in the form {epsilon}{sub min}t{sub r}=3{radical}{epsilon}{sup 2}{sub 23}.{epsilon}{sub r}. (orig./MM). [Deutsch] Es sind in letzter Zeit wieder aeltere
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Citation Formats
Radhakrishnan, V M, Ennis, P J, and Schuster, H.
An analysis of creep deformation and rupture by the {beta}-envelope method.
Germany: N. p.,
1991.
Web.
Radhakrishnan, V M, Ennis, P J, & Schuster, H.
An analysis of creep deformation and rupture by the {beta}-envelope method.
Germany.
Radhakrishnan, V M, Ennis, P J, and Schuster, H.
1991.
"An analysis of creep deformation and rupture by the {beta}-envelope method."
Germany.
@misc{etde_10140854,
title = {An analysis of creep deformation and rupture by the {beta}-envelope method}
author = {Radhakrishnan, V M, Ennis, P J, and Schuster, H}
abstractNote = {Recently early approaches based on creep equations have been revived to describe the creep deformation and fracture. In this report creep equations of the type {epsilon}{sub 1}={beta}{sub 1}t{sup 1/3}, {epsilon}{sub 2}={beta}{sub 2}t and {epsilon}{sub 3}={beta}{sub 3}t{sup 3} where {epsilon}{sub 1}, {epsilon}{sub 2}, {epsilon}{sub 3} are the creep strains in the primary, secondary and tertiary stages, {beta}{sub i} the respective coefficients and t the time, are used to envelope the creep strain data on the log-log plot of creep strain versus time. Based on this approach the creep behaviour of the following engineering materials has been analysed: X10 NiCrAlTi 32 20 (Alloy 800 H), 13 CrMo 4 4 (1 Cr-0.5 Mo) steel in both new and service exposed conditions, 14 CrMoV 6 3 (0.5 Cr-0.5 Mo-0.25 V) steel a Ni-base superalloy. The analysis leads to an important modification of the Dobes-Milicka rule, namely, that the minimum creep rate {epsilon}{sub min} and the rupture time t{sub r} are related not only to the creep rupture strain {epsilon}{sub r} but also to the creep strain at the end of the second stage {epsilon}{sub 23}, given in the form {epsilon}{sub min}t{sub r}=3{radical}{epsilon}{sup 2}{sub 23}.{epsilon}{sub r}. (orig./MM). [Deutsch] Es sind in letzter Zeit wieder aeltere Ansaetze verwendet worden, um Kriechverformung und -bruch zu beschreiben. Von Interesse sind die einfachen Formulierungen, die eine leicht handhabbare mathematische Beschreibung der Basisdaten ermoeglichen sollen. In diesem Bericht werden Gleichungen algebraischen Types, wie z.B. {epsilon}{sub 1}={beta}{sub 1}t{sup 1/3}, {epsilon}{sub 2}={beta}{sub 2}t, {epsilon}{sub 3}={beta}{sub 3}t{sup 3} ({epsilon}{sub i}: Kriechdehnungen, {beta}{sub i}= Koeffizienten, t: Einwirkungsdauer) verwendet, um gemessene Kriechkurven zu approximieren. Auf diesem Wege wurde das Kriechverhalten von X10 NiCrAlTi 32 20 (Alloy 800H), 13 CrMo 4 4 (1 Cr-0,5 Mo-Stahl), 14 MoV 6 3 (0,5 Cr-0,5 Mo-0,25 V-Stahl) einer Ni-Basis-Legierung formuliert. Die Analyse zeigt, dass diese einfachen Gleichungen die Daten in weiten Bereichen gut beschreiben, und dass die funktionellen Abhaengigkeiten der Koeffizienten eine vernuenftige Extrapolation ueber den experimentell erfassten Bereich hinaus gestatten. Daneben laesst sich aus diesen Gleichungen eine neue Beziehung fuer die Konstante der Monkman-Grant-Gleichung definieren: {epsilon}{sub min}t{sub r}=3{radical}{epsilon}{sup 2}{sub 23}.{epsilon}{sub r}, wobei {epsilon}{sub 23} die Kriechdehnung am Ende des stationaeren Kriechens und {epsilon}{sub r} die Kriechbruchdehnung sind. (orig./MM).}
place = {Germany}
year = {1991}
month = {Oct}
}
title = {An analysis of creep deformation and rupture by the {beta}-envelope method}
author = {Radhakrishnan, V M, Ennis, P J, and Schuster, H}
abstractNote = {Recently early approaches based on creep equations have been revived to describe the creep deformation and fracture. In this report creep equations of the type {epsilon}{sub 1}={beta}{sub 1}t{sup 1/3}, {epsilon}{sub 2}={beta}{sub 2}t and {epsilon}{sub 3}={beta}{sub 3}t{sup 3} where {epsilon}{sub 1}, {epsilon}{sub 2}, {epsilon}{sub 3} are the creep strains in the primary, secondary and tertiary stages, {beta}{sub i} the respective coefficients and t the time, are used to envelope the creep strain data on the log-log plot of creep strain versus time. Based on this approach the creep behaviour of the following engineering materials has been analysed: X10 NiCrAlTi 32 20 (Alloy 800 H), 13 CrMo 4 4 (1 Cr-0.5 Mo) steel in both new and service exposed conditions, 14 CrMoV 6 3 (0.5 Cr-0.5 Mo-0.25 V) steel a Ni-base superalloy. The analysis leads to an important modification of the Dobes-Milicka rule, namely, that the minimum creep rate {epsilon}{sub min} and the rupture time t{sub r} are related not only to the creep rupture strain {epsilon}{sub r} but also to the creep strain at the end of the second stage {epsilon}{sub 23}, given in the form {epsilon}{sub min}t{sub r}=3{radical}{epsilon}{sup 2}{sub 23}.{epsilon}{sub r}. (orig./MM). [Deutsch] Es sind in letzter Zeit wieder aeltere Ansaetze verwendet worden, um Kriechverformung und -bruch zu beschreiben. Von Interesse sind die einfachen Formulierungen, die eine leicht handhabbare mathematische Beschreibung der Basisdaten ermoeglichen sollen. In diesem Bericht werden Gleichungen algebraischen Types, wie z.B. {epsilon}{sub 1}={beta}{sub 1}t{sup 1/3}, {epsilon}{sub 2}={beta}{sub 2}t, {epsilon}{sub 3}={beta}{sub 3}t{sup 3} ({epsilon}{sub i}: Kriechdehnungen, {beta}{sub i}= Koeffizienten, t: Einwirkungsdauer) verwendet, um gemessene Kriechkurven zu approximieren. Auf diesem Wege wurde das Kriechverhalten von X10 NiCrAlTi 32 20 (Alloy 800H), 13 CrMo 4 4 (1 Cr-0,5 Mo-Stahl), 14 MoV 6 3 (0,5 Cr-0,5 Mo-0,25 V-Stahl) einer Ni-Basis-Legierung formuliert. Die Analyse zeigt, dass diese einfachen Gleichungen die Daten in weiten Bereichen gut beschreiben, und dass die funktionellen Abhaengigkeiten der Koeffizienten eine vernuenftige Extrapolation ueber den experimentell erfassten Bereich hinaus gestatten. Daneben laesst sich aus diesen Gleichungen eine neue Beziehung fuer die Konstante der Monkman-Grant-Gleichung definieren: {epsilon}{sub min}t{sub r}=3{radical}{epsilon}{sup 2}{sub 23}.{epsilon}{sub r}, wobei {epsilon}{sub 23} die Kriechdehnung am Ende des stationaeren Kriechens und {epsilon}{sub r} die Kriechbruchdehnung sind. (orig./MM).}
place = {Germany}
year = {1991}
month = {Oct}
}