Extrapolation of Creep Strain Data for Pure Copper

1999 ◽  
Vol 27 (1) ◽  
pp. 31 ◽  
Author(s):  
DR Petersen ◽  
RE Link ◽  
R Sandström
Keyword(s):  
Creep Strain ◽  
Pure Copper ◽  
Strain Data

On the Interrupted Creep Test Under Low Stress Levels for the Power Law Parameter Extraction

2020 ◽  
Vol 142 (5) ◽  
Author(s):  
Bin Yang ◽  
Fu-Zhen Xuan ◽  
Wen-Chun Jiang
Keyword(s):  
Creep Strain ◽  
Stress Level ◽  
Creep Test ◽  
Creep Deformation ◽  
Parameter Extraction ◽  
Tertiary Creep ◽  
Secondary Creep ◽  
Creep Stage ◽  
Strain Data

Abstract Low stress interrupted creep test, as an interim compromise, can provide essential data for creep deformation design. However, there are no clear guidelines on the characterization of the terminating time for interrupted low-stress creep test. To obtain a suitable terminating time in terms of economy and effectiveness, long-term creep strain data of 9%Cr steels are collected from literatures and their creep deformation characterization is analyzed. First, the variations of normalized time and strain of each creep stage with the stress level are discussed. Then, the effect of the terminating time on final fitted results of Norton–Bailey equation is estimated. Third, the relationship between demarcation points at different creep stages and minimum/steady-state creep rate is analyzed. The results indicate that when the creep rupture life is considered as an important factor for creep design, the tertiary creep stage is of greatest significance due to the largest life fraction and creep strain fraction at low stress level. However, the primary and secondary creep stages are of great significance for design due to their larger contribution to 1% limited creep strain. And the long-term secondary creep data could be extrapolated by combining the primary creep strain data obtained from interrupted creep tests with the time to onset of tertiary creep derived from a similar Monkman–Grant relationship.

Extrapolation of Creep Strain and Rupture Properties of 1/2 per Cent Cr, 1/2 per Cent Mo, 1/4 per Cent V Pipe Steel

1970 ◽  
Vol 185 (1) ◽  
pp. 285-299 ◽  
Author(s):  
W. M. Cummings ◽  
R. H. King
Keyword(s):  
Creep Strain ◽  
Material Properties ◽  
Pipe Steel ◽  
Parametric Methods ◽  
Time Estimates ◽  
Rupture Data ◽  
Strain Data ◽  
Long Time ◽  
Accuracy Of Prediction ◽  
Rupture Properties

Both 1 per cent total plastic strain data and rupture data of up to 21 000 h duration are presented for 1/2 per cent Cr, 1/2 per cent Mo, 1/4 per cent V pipe steel. Four parametric methods commonly used for extrapolation purposes are assessed for their accuracy of prediction within the time covered by the present experimental data. The Manson-Haferd parameter, which emerged as the most satisfactory of the four, is used as the basis for the long-time estimates of material properties. Based on the full 1 per cent strain and rupture data, 10 000, 30 000 and 100 000 h predictions are compared with the current British Steelmakers' Creep Committee recommendations. The tendency of both the Larson-Miller and Orr-Sherby-Dorn parameters to provide optimistic estimates at longer times is again demonstrated, and while the Manson Generalized parameter fits the data excellently within the experimental range, it is shown that care is required in selecting values of parametric constants if instability is to be avoided. To meet the increasing need for long-time creep strain data, each individual creep curve is represented by a creep strain/time relationship.

scholarly journals AGC 2 Irradiation Creep Strain Data Analysis

2016 ◽  
Author(s):  
William E. Windes ◽  
David T. Rohrbaugh ◽  
W. David Swank
Keyword(s):  
Data Analysis ◽  
Creep Strain ◽  
Irradiation Creep ◽  
Strain Data

scholarly journals AGC 3 Irradiation Creep Strain Data Analysis

2019 ◽  
Author(s):  
William E Windes ◽  
David T Rohrbaugh ◽  
W David Swank
Keyword(s):  
Data Analysis ◽  
Creep Strain ◽  
Irradiation Creep ◽  
Strain Data

Monitoring Creep Strain in Power Station Engineering Plant

2007 ◽  
Vol 7-8 ◽  
pp. 31-36 ◽  
Author(s):  
Andrew Morris ◽  
John P. Dear ◽  
Miltiadis Kourmpetis ◽  
Chris Maharaj ◽  
Amit Puri ◽  
...  
Keyword(s):  
Creep Strain ◽  
Carbon Dioxide Emissions ◽  
Cost Effective ◽  
Low Carbon ◽  
Reliable Operation ◽  
Power Station ◽  
Engineering Plant ◽  
Measurement Systems ◽  
Strain Data ◽  
Steam Pipes

Cost effective and reliable operation of a power station plant and achieving low carbon dioxide emissions can be very dependent on maintenance activities. Planning maintenance to minimise the down-time of the plant is a key cost factor. It is important to have the latest data as to the age and state of the components and parts at the time of plant shut down. Indeed, deciding on the best time to shut down the plant for maintenance can depend upon trends in these data. For steam pipes, the required ageing information is the creep strain rate. These creep strain data obtained at shut down provide key information as to the needed replacement of pipes to maintain reliable plant operation. This paper presents the E.ON UK ARCMAC creep strain measurement systems that are being further developed by Imperial College London with the use of DIC and other techniques.

Creep Recovery of Commercially Pure Copper

1968 ◽  
Vol 10 (1) ◽  
pp. 24-35 ◽  
Author(s):  
J. Henderson ◽  
J. D. Snedden
Keyword(s):  
Creep Strain ◽  
Creep Test ◽  
Recovery Time ◽  
Empirical Equation ◽  
Pure Copper ◽  
Creep Recovery ◽  
Recoverable Strain ◽  
Commercially Pure ◽  
Commercially Pure Copper

Tension and torsion creep recovery tests on commercially pure copper at 150, 200 and 250°C are reported. Recoverable strain can range from a negligible percentage to approaching 100 per cent of the total creep strain developed, depending on stress, creep period preceding unloading, and current recovery time. An empirical equation relating creep recovery to these characteristics of the initial creep test is given.

TEM study of a biofilm on copper corrosion

1996 ◽  
Vol 54 ◽  
pp. 220-221
Author(s):  
W. A. Chiou ◽  
N. Kohyama ◽  
B. Little ◽  
P. Wagner ◽  
M. Meshii
Keyword(s):  
Marine Bacterium ◽  
Culture Medium ◽  
Copper Alloys ◽  
Pure Copper ◽  
Localized Corrosion ◽  
Natural Seawater ◽  
Copper Corrosion ◽  
New Approach ◽  
The Past ◽  
Copper Tolerant

The corrosion of copper and copper alloys in a marine environment is of great concern because of their widespread use in heat exchangers and steam condensers in which natural seawater is the coolant. It has become increasingly evident that microorganisms play an important role in the corrosion of a number of metals and alloys under a variety of environments. For the past 15 years the use of SEM has proven to be useful in studying biofilms and spatial relationships between bacteria and localized corrosion of metals. Little information, however, has been obtained using TEM capitalizing on its higher spacial resolution and the transmission observation of interfaces. The research presented herein is the first step of this new approach in studying the corrosion with biological influence in pure copper.Commercially produced copper (Cu, 99%) foils of approximately 120 μm thick exposed to a copper-tolerant marine bacterium, Oceanospirillum, and an abiotic culture medium were subsampled (1 cm × 1 cm) for this study along with unexposed control samples.

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