scholarly journals DEGRADATION OF THE MAIN GAS PIPELINE MATERIAL AND MECHANISMS OF ITS FRACTURE

2014 ◽  
Vol 20 (6) ◽  
pp. 864-872 ◽  
Author(s):  
Pavlo Maruschak ◽  
Iryna Danyliuk ◽  
Olegas Prentkovskis ◽  
Roman Bishchak ◽  
Andriy Pylypenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Deformation Process ◽  
Pipe Wall ◽  
Gas Pipeline ◽  
Static Deformation ◽  
Term Operation ◽  
Damage And Fracture ◽  
Scattered Damage ◽  
Main Gas Pipeline

The effect of the in-service scattered damage in the pipe wall metal is evaluated, and the effect of hydrogen absorbed by metal on the variation of the structure and mechanical properties of the main gas pipeline after a long-term operation is found. The main regularities in the graded nature of the static deformation process and the effect of hydrogenation on the scattered damage and fracture accumulation are found.

Study of the mechanical properties of the gas pipeline metal after long-term operation in conditions of the North

2020 ◽  
Vol 86 (6) ◽  
pp. 48-54
Author(s):  
N. I. Golikov ◽  
M. M. Sidorov ◽  
I. I. Sannikov ◽  
A. K. Rodionov
Keyword(s):  
Mechanical Properties ◽  
Residual Strength ◽  
Linear Part ◽  
Full Scale ◽  
Gas Pipeline ◽  
Term Operation ◽  
The North ◽  
Full Scale Tests ◽  
Main Gas Pipeline

The residual strength and technical condition of the material of 530-mm steel pipe (14KhGS) of main gas pipeline are estimated to ensure the safety of long-term operation of pipelines in climatic conditions of the North. The mechanical properties are determined using standard methods of mechanical testing in laboratory conditions. A full-scale pressure test up to failure is used to determine the actual values of the fracture toughness and safety factor of the pipe. Full-scale tests were carried out on a test bench, a computer-measuring complex which displayed the reaction of the object to the load. A pipe fragment was cut from the linear part of the main gas pipeline and welded with spherical plugs. The outer surface of the pipe was notched along the pipe axis. The depth of the notch was calculated such that the breaking load on the ligament section at the notch site corresponded to the working pressure of the gas pipeline. No significant changes in the mechanical properties of the pipe metal were revealed in the absence of visible corrosion and deformation damage during long-term operation of the pipe in the North. Impact tests did not reveal embrittlement of the metal of the tested pipes. Full-scale tests of a pipe with an artificially applied defect made it possible to calculate the value of the critical stress intensity factor, which allowed us to estimate the residual strength of a pipe with a longitudinal crack. The value of the strength criterion of the fracture mechanics indicates the preservation of a sufficiently high viscosity of sheet metal pipes. Similar tests of the pipes (of other size and made of other materials) operating in the main gas pipelines should be continued taking into account temperature ranges and material degradation after long-term operation.

scholarly journals Investigation of mechanical properties of the main gas pipeline material during a long-term operation in conditions of the North

2020 ◽  
Vol 30 ◽  
pp. 144-148
Author(s):  
Igor Sannikov ◽  
Nikolay Golikov ◽  
Nikolay Terentyev ◽  
Pavel Ksenofontov ◽  
Aisen Zhirkov
Keyword(s):  
Mechanical Properties ◽  
Gas Pipeline ◽  
Term Operation ◽  
The North ◽  
Main Gas Pipeline

Effect of long-term operation on steels of main gas pipeline. Reduction of static fracture toughness

2017 ◽  
Vol 38 ◽  
pp. 182-186 ◽  
Author(s):  
P.O. Maruschak ◽  
S.V. Panin ◽  
M.G. Chausov ◽  
R.T. Bishchak ◽  
U.V. Polyvana
Keyword(s):  
Fracture Toughness ◽  
Gas Pipeline ◽  
Term Operation ◽  
Static Fracture ◽  
Main Gas Pipeline

scholarly journals Effect of long-term operation on steels of main gas pipeline: Structural and mechanical degradation

2018 ◽  
Vol 30 (4) ◽  
pp. 363-367 ◽  
Author(s):  
Pavlo Maruschak ◽  
Sergey Panin ◽  
Mykola Chausov ◽  
Roman Bishchak ◽  
Ulyana Polyvana
Keyword(s):  
Gas Pipeline ◽  
Mechanical Degradation ◽  
Term Operation ◽  
Main Gas Pipeline

Evaluation of the residual lifetime of a section of a main gas pipeline after long-term operation

2012 ◽  
Vol 48 (2) ◽  
pp. 231-238 ◽  
Author(s):  
O. E. Andreikiv ◽  
O. V. Hembara ◽  
O. T. Tsyrul’nyk ◽  
L. I. Nyrkova
Keyword(s):  
Gas Pipeline ◽  
Residual Lifetime ◽  
Term Operation ◽  
Main Gas Pipeline

scholarly journals Mechanical Properties of Gas Main Steels after Long-Term Operation and Peculiarities of Their Fracture Surface Morphology

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 491 ◽  
Author(s):  
Volodymyr Hutsaylyuk ◽  
Pavlo Maruschak ◽  
Ihor Konovalenko ◽  
Sergey Panin ◽  
Roman Bishchak ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Surface ◽  
Damage Accumulation ◽  
Classification Scheme ◽  
Steel Structure ◽  
Term Operation ◽  
Gas Main ◽  
Structure Degradation ◽  
Main Pipelines

Regularities of steel structure degradation of the “Novopskov-Aksay-Mozdok” gas main pipelines (Nevinnomysskaya CS) as well as the “Gorky-Center” pipelines (Gavrilovskaya CS) were studied. The revealed peculiarities of their degradation after long-term operation are suggested to be treated as a particular case of the damage accumulation classification (scheme) proposed by prof. H.M. Nykyforchyn. It is shown that the fracture surface consists of sections of ductile separation and localized zones of micro-spalling. The presence of the latter testifies to the hydrogen-induced embrittlement effect. However, the steels under investigation possess sufficiently high levels of the mechanical properties required for their further safe exploitation, both in terms of durability and cracking resistance.

Determination of Actual Tensile and Fracture Characteristics of Critical Components of Industrial Plants Under Long Term Operation by SPT

2012 ◽  
Author(s):  
Karel Matocha
Keyword(s):  
Mechanical Properties ◽  
Residual Lifetime ◽  
Test Technique ◽  
Fracture Characteristics ◽  
Industrial Plants ◽  
Term Operation ◽  
Critical Components ◽  
Time Of Operation

The assessment of the residual lifetime of critical components of industrial plants requires the knowledge of mechanical properties prior to operation, respecting all technological operations realized throughout the manufacture of the component, and the knowledge of mechanical properties after actual time of operation (actual mechanical properties). Small Punch (SP) test technique enables measurement of the realistic material properties at the critical locations in the component both prior and after long-term operation. The paper shows the examples of the sampling of testing material from the critical components of the industrial plants and the procedures for determination of tensile and fracture characteristics by SP tests at ambient and low temperatures. The special attention is devoted to the test specimen orientation for determination of SP fracture energy ESP.

Determination of Tensile Properties of Power Plant Steels by Testing of Miniature Specimens

2013 ◽  
Author(s):  
Ivan Klevtsov ◽  
Andrei Dedov
Keyword(s):  
Mechanical Properties ◽  
Power Plant ◽  
Flat Plate ◽  
Tensile Properties ◽  
Standard Size ◽  
Term Operation ◽  
University Of Technology ◽  
Miniature Specimens

Long-term operation of the power plant components in the conditions of the creep leads to the degradation of the short-term mechanical properties of the material. Therefore, in order to predict the degree of the metal degradation and integrity of the component the determination of the mechanical properties of the actual component in service material is required. Since the standard tests requiring a significant volume of sample material cannot be applied the technique of the tensile testing of miniature flat plate specimens has been developed in Tallinn University of Technology and described in this paper. The results of the tests of miniature flat plate specimens have been compared with testing results of cylindrical specimens with standard size and at the same time the comparison has shown a good agreement of the results. The data analysis has also shown the high repeatability of the tests results of miniature specimens. Thus, the developed technique of the miniature flat plate specimens testing could be considered as accurate and reliable method and could be definitely used for evaluation of the tensile properties of the metal.

scholarly journals Effect of Long Term Service at Elevated Temperatures on Mechanical Properties of Manaurite XM Reformer Tubes

2016 ◽  
Vol 16 (4) ◽  
pp. 38-44
Author(s):  
J. Łabanowski ◽  
M. Jurkowski ◽  
M. Landowski
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperatures ◽  
Cast Steel ◽  
Internal Diameter ◽  
Term Operation ◽  
Static Tensile ◽  
Different Shapes ◽  
Reformer Tubes ◽  
The Relationship

Abstract Microstructure transformations occur in the Manaurite XM cast steel tubes during long-term operation in the reformer furnace were revealed and described. The relationship between mechanical properties, an increase of internal diameter of the tube and microstructure degradation is discussed. Static tensile test was performed on two types of samples with different shapes. It has been shown differences in the results of tests and an explanation of this phenomenon.

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