scholarly journals Residual life assessment of a pipeline bend by using small punch creep tests

2021 ◽  
Author(s):  
Zdeněk KUBOŇ
Author(s):  
Junichi Kusumoto ◽  
Akihiro Kanaya ◽  
Toshimi Kobayashi

The non-destructive techniques such as the microstructural assessment are usually performed for residual creep life assessment of plant components. Since these techniques have limited accuracy, destructive assessment techniques such as uniaxial creep tests are required to improve the accuracy of the assessment. However, if this type of destructive assessment technique are applied, the sampling and the weld repair damages the material, and also the assessment will become expensive. On the other hand, small punch creep (SPC) test [1,2], which uses miniature-sized specimens, does not cause any serious sampling damages, and its assessment accuracy is high since it is a mechanical assessment technique. However, in applying the SPC test to the residual creep life assessment of the boiler in service, there are some issues to be studied [1,3,4]. In order to apply SPC test to the residual creep life assessment of the 2.25Cr-1Mo steel boiler pipe, the relationship between uniaxial creep stress and the SPC test load has been studied. And the Omega method [5] by SPC test was also studied.


2004 ◽  
Vol 2004 (0) ◽  
pp. 179-180
Author(s):  
Masataka NAGAE ◽  
Satoshi OGAWA ◽  
Akihiro KANAYA ◽  
Toshimi KOBAYASHI ◽  
Makoto HARADA

Author(s):  
Toshimi Kobayashi ◽  
Toru Izaki ◽  
Junichi Kusumoto ◽  
Akihiro Kanaya

The small punch creep (SPC) test is possible to predict residual creep life at a high accuracy. But, the results of SPC tests cannot be compared with uniaxial creep or internal pressure creep results directly. In this report, the relationship between SPC test results and uniaxial creep test results in ASME A335 P11 (1.25Cr-0.5Mo Steel) was studied. The obtained relationship between SPC load and equivalent uniaxial creep stress formed a simple linear equation under the wide range of test temperature and test period. Then, the SPC results can be compared with uniaxial results by converting SPC loads to the equivalent uniaxial creep stresses. The relationship between SPC test results and internal pressure creep tests results was also studied. The internal creep life of as-received P11 pipe was almost same as SPC result when the hoop stress was converted to the SPC load. The creep lives of internal pressure creep influenced materials also showed good correspondence with SPC results. Therefore SPC can estimate the residual life of internal pressure creep influenced materials.


Author(s):  
Mayank Bajaj ◽  
Biswajit Bhattacharjee

<p>While concrete structures perform well in many situations, lack of durability has emerged as a significant issue for asset owners. A review of past bridge failures was done to identify the most probable causes of bridge failures. This study has tended to focus on current models used for estimating the time to deterioration of concrete bridges instigated by Chloride ingress and Fatigue. Subsequently, mathematical modelling of the best-suited deterioration model is done to arrive at the residual life of two existing bridges. This work has highlighted high variability in the parameters used to describe the durability related properties of in-situ aged concrete. A realistic residual life assessment can be achieved by correct evaluation of these parameters by periodic testing of bridge samples</p>


2006 ◽  
Vol 38 (4) ◽  
pp. 348-353 ◽  
Author(s):  
A. A. Lebedev ◽  
V. M. Mikhalevich

1988 ◽  
Vol 110 (3) ◽  
pp. 308-313 ◽  
Author(s):  
F. Mlynarski ◽  
J. Taler

This paper discusses different methods for calculating the residual life for boiler pressure components operating under creep conditions, based on tube outside diameter strain measurements. These measurements were made for over 20 yr. The methods have been applied to the residual life calculation for pipelines of 20 or more years of service. Then the results have been compared.


2009 ◽  
Vol 413-414 ◽  
pp. 219-228 ◽  
Author(s):  
John R. Maguire

This case study describes a structural integrity assessment of a 220 kV overhead power line. The line comprises 70 pylons over a distance of approximately 30 km, predominantly in a valley location. The pylons are spaced at intervals of approximately 400 m and each pylon is approximately 32 m in height. The line was originally constructed in the 1950’s, approximately 50 years prior to the requested structural integrity assessment. This paper describes the independent assessment that was carried out. The review established site-specific safety factors at the time of original design and construction; at the time of the review (2007), accounting for the possible presence of the “Thomasstahl” steel; and in the future, at the anticipated end of pylon life (in 2012).


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