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.

Microstructure and Mechanical Properties of G17CrMoV5 – 10 Cast Steel After Regenerative Heat Treatment

2009 ◽  
Author(s):  
Grzegorz Golan´ski
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Impact Energy ◽  
Cast Steel ◽  
Optimum Combination ◽  
Austenitizing Temperature ◽  
Regenerative Heat ◽  
Term Operation ◽  
Structure Degradation

The paper presents results of research on the influence of regenerative heat treatment on microstructure and properties of a cast steel after long term operation at the elevated temperature. The material under investigation was G17CrMoV5 – 10 cast steel taken out (in the form of a section) from an internal frame of steam turbine serviced for about 250 000 hours. Performed research has proved that, through the structure degradation, long-term service contributes to an increase of brittleness and decrease of mechanical properties — higher in the case of yield strength than tensile strength. The heat treatment, however, contributes to an increase of impact energy, regardless of the applied parameters. Is has also been proved that the optimum combination of mechanical properties and impact energy is ensured by the structure of high tempered bainite. Low mechanical properties and impact energy, however, were obtained for the structure which was slowly cooled from the austenitizing temperature, i.e. the ferritic – bainitic – ferritic structure.

Physical metallurgy conditions for retaining the load-carrying ability of the gas-main pipeline metal during long-term operation

2009 ◽  
Vol 2009 (4) ◽  
pp. 314-321 ◽  
Author(s):  
M. M. Kantor ◽  
V. N. Voronin ◽  
V. A. Bozhenov ◽  
V. G. Antonov ◽  
Yu. M. Sharygin
Keyword(s):  
Physical Metallurgy ◽  
Main Pipeline ◽  
Term Operation ◽  
Gas Main ◽  
Gas Main Pipeline ◽  
Load Carrying

Degradation of the pipe-steel structure upon long-term operation in contact with a hydrogen sulfide-containing medium

2011 ◽  
Vol 111 (3) ◽  
pp. 281-293 ◽  
Author(s):  
V. M. Schastlivtsev ◽  
T. I. Tabatchnikova ◽  
N. A. Tereshchenko ◽  
I. L. Yakovleva
Keyword(s):  
Hydrogen Sulfide ◽  
Pipe Steel ◽  
Steel Structure ◽  
Term Operation

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.

Analysis of the fracture surface of steel 10 in the initial state and after long-term operation

1987 ◽  
Vol 29 (10) ◽  
pp. 788-791
Author(s):  
B. S. Ermakov ◽  
G. G. Kolchin ◽  
A. Z. Kevesh
Keyword(s):  
Fracture Surface ◽  
Initial State ◽  
Term Operation

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.

scholarly journals Impact of Long-Term Operation on the Reliability and Durability of Transit Gas Pipelines

2020 ◽  
Vol 70 (1) ◽  
pp. 115-126
Author(s):  
Okipnyi Igor ◽  
Poberezhny Lyubomyr ◽  
Zapukhliak Vasyl ◽  
Hrytsanchuk Andrii ◽  
Poberezhna Liubov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Fatigue ◽  
Static Loading ◽  
Physical And Mechanical Properties ◽  
Fatigue Tests ◽  
Gas Pipelines ◽  
Term Operation ◽  
Full Capacity ◽  
Corrosive Environments

AbstractCorrosion and corrosion-fatigue tests of the material of the pipeline, which was in operation for 41 years. It has been shown that prolonged operation reduces the parameters of resistance to fatigue and prolonged static loading in corrosive environments. It was established that the degradation of physical and mechanical properties is insignificant, Ukraine’s main gas pipelines are ready to operate at full capacity provided that timely monitoring measures are carried out.

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