Influence of Long-Term Operation on Physical and Mechanical Properties and Cold Resistance Indicators of  Pipe Steel 10G2

Проведено исследование влияния длительности эксплуатации магистрального газопровода на изменение физико-механических характеристик показателей хладостойкости трубной стали 10Г2.Установлено, что в процессе длительной эксплуатации стали 10Г2 в составе магистрального газопровода наблюдается изменение структуры металла, при этом происходит перераспределение перлитной составляющей и укрупнение зерен. Получены значения микротвердости исследуемой стали до и после эксплуатации (10, 25, 40 лет). Длительная эксплуатация (40 лет) материала труб приводит к росту значений микротвердости с 1518 до 2786 HV. Выявлено двукратное снижение значений ударной вязкости стали 10Г2 после старения и эксплуатации в течение 25 лет. Также наблюдается значительное повышение температуры вязкохрупкого перехода, что снижает надежность магистральных трубопроводов. В результате испытаний стали 10Г2 в широком диапазоне температур после 25 лет эксплуатации наблюдается снижение пластичности металла (относительное удлинение уменьшается примерно в 1,6 раза), повышение предела прочности и снижение предела текучести (до 9 %).Предложена методика неразрушающего контроля деградации механических свойств стали 10Г2 в процессе эксплуатации изделий. Установлена зависимость акустического параметра D, рассчитанного на основе скорости распространения продольных и поперечных упругих волн в металле от срока эксплуатации газовых магистральных труб и температуры вязкохрупкого перехода для стали 10Г2. Показано, что предложенный акустический параметр может выступать в качестве характеристического параметра хладостойкости материала магистральных газопроводов и использоваться при технической диагностике для оценки их остаточного ресурса.Исследование выполнено по гранту РНФ № 19-19-00332 «Разработка научно обоснованных подходов и аппаратно-программных средств мониторинга поврежденности конструкционных материалов на основе подходов искусственного интеллекта для обеспечения безопасной эксплуатации технических объектов в арктических условиях».

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

Strojnícky casopis – Journal of Mechanical Engineering ◽

10.2478/scjme-2020-0011 ◽

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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Long-Term Physical and Mechanical Properties and Microstructures of Fly-Ash-Based Geopolymer Composite Incorporating Carbide Slag

Materials ◽

10.3390/ma14216692 ◽

2021 ◽

Vol 14 (21) ◽

pp. 6692

Author(s):

Xianhui Zhao ◽

Haoyu Wang ◽

Linlin Jiang ◽

Lingchao Meng ◽

Boyu Zhou ◽

...

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Room Temperature ◽

Physical And Mechanical Properties ◽

Drying Shrinkage ◽

Fine Aggregate ◽

Property Development ◽

Industrial Solid Waste ◽

Carbide Slag

The long-term property development of fly ash (FA)-based geopolymer (FA−GEO) incorporating industrial solid waste carbide slag (CS) for up to 360 d is still unclear. The objective of this study was to investigate the fresh, physical, and mechanical properties and microstructures of FA−GEO composites with CS and to evaluate the effects of CS when the composites were cured for 360 d. FA−GEO composites with CS were manufactured using FA (as an aluminosilicate precursor), CS (as a calcium additive), NaOH solution (as an alkali activator), and standard sand (as a fine aggregate). The fresh property and long-term physical properties were measured, including fluidity, bulk density, porosity, and drying shrinkage. The flexural and compressive strengths at 60 d and 360 d were tested. Furthermore, the microstructures and gel products were characterized by scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The results show that the additional 20.0% CS reduces the fluidity and increases the conductivity of FA−GEO composites. Bulk densities were decreased, porosities were increased, and drying shrinkages were decreased as the CS content was increased from 0.0% to 20.0% at 360 d. Room temperature is a better curing condition to obtain a higher long-term mechanical strength. The addition of 20.0% CS is more beneficial to the improvement of long-term flexural strength and toughness at room temperature. The gel products in CS−FA−GEO with 20.0% CS are mainly determined as the mixtures of sodium aluminosilicate (N−A−S−H) gel and calcium silicate hydration (C−S−H) gel, besides the surficial pan-alkali. The research results provide an experimental basis for the reuse of CS in various scenarios.

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

Materials ◽

10.3390/ma12030491 ◽

2019 ◽

Vol 12 (3) ◽

pp. 491 ◽

Cited By ~ 6

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.

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The influence of physical and mechanical properties of additional materials on the recycled rubber structure during its disposal

E3S Web of Conferences ◽

10.1051/e3sconf/201911600002 ◽

2019 ◽

Vol 116 ◽

pp. 00002 ◽

Cited By ~ 4

Author(s):

Imad Rezakalla Antypas ◽

Ghias Kharmanda ◽

Alexey Dyachenko ◽

Tatiana Savostina

Keyword(s):

Mechanical Properties ◽

Physical And Mechanical Properties ◽

Stress Strain ◽

Long Term Storage ◽

Environmental Damages ◽

Recycled Rubber ◽

Different Diameters ◽

Term Storage

During the rubber long-term storage in the open air and under the influence of certain temperatures, there is a real threat to the environment where environmental damages cannot be ignored. The objective of this paper is to study the mechanical properties of rubber during its processing by vulcanization after adding some materials to improve their properties. The used materials are: rubber from tires where the proportion of rubber varies from 70-78%, vulcanization granules of rubber, non-vulcanized natural NR rubber, and granulated sulphur. Curves of stress-strain of the recycled rubber are modelled at different diameters of the granules added to the materials for vulcanization removal. As result, the improvement of the mechanical properties are obtained by increasing the diameter of the granules but there a threshold which should not be exceeded.

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Assessing the physical and mechanical properties of poly 3‐hydroxybutyrate‐chitosan‐multi‐walled carbon nanotube/silk nano–micro composite scaffold for long‐term healing tissue engineering applications

Micro & Nano Letters ◽

10.1049/mnl.2017.0725 ◽

2018 ◽

Vol 13 (6) ◽

pp. 829-834 ◽

Cited By ~ 2

Author(s):

Mohammad H. Mirmusavi ◽

Saeed Karbasi ◽

Dariush Semnani ◽

Mohammad Rafienia ◽

Anousheh Zargar Kharazi

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Carbon Nanotube ◽

Composite Scaffold ◽

Physical And Mechanical Properties ◽

Engineering Applications ◽

Multi Walled Carbon Nanotube ◽

Healing Tissue

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

The Physics of Metals and Metallography ◽

10.1134/s0031918x11020128 ◽

2011 ◽

Vol 111 (3) ◽

pp. 281-293 ◽

Cited By ~ 3

Author(s):

V. M. Schastlivtsev ◽

T. I. Tabatchnikova ◽

N. A. Tereshchenko ◽

I. L. Yakovleva

Keyword(s):

Hydrogen Sulfide ◽

Pipe Steel ◽

Steel Structure ◽

Term Operation

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Structural and mechanical degradation of 09Mn2Si pipe steel after long-term operation

10.1063/1.5013848 ◽

2017 ◽

Cited By ~ 1

Author(s):

S. V. Panin ◽

P. O. Marushchak ◽

I. V. Vlasov ◽

A. V. Eremin ◽

A. V. Byakov ◽

...

Keyword(s):

Pipe Steel ◽

Mechanical Degradation ◽

Term Operation

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Degradation of mechanical properties of CrMoV and CrMoVW steam turbine rotors after long-term operation at elevated temperatures. Part I: tensile properties, intergranular fracture strength and impact tests

International Journal of Pressure Vessels and Piping ◽

10.1016/0308-0161(94)00044-1 ◽

1996 ◽

Vol 68 (1) ◽

pp. 99-111 ◽

Cited By ~ 5

Author(s):

M. Holzmann ◽

I. Dlouhý ◽

B. Vlach ◽

J. Krumpos

Keyword(s):

Mechanical Properties ◽

Steam Turbine ◽

Tensile Properties ◽

Intergranular Fracture ◽

Fracture Strength ◽

Elevated Temperatures ◽

Term Operation ◽

Impact Tests ◽

Degradation Of Mechanical Properties

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

Volume 6: Materials and Fabrication, Parts A and B ◽

10.1115/pvp2012-78553 ◽

2012 ◽

Cited By ~ 2

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.

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