Hydrate Formations Modeling for the Oil and Gas Facilities Reconstruction

Макаренко, В. Д.; Vynnykov, Yuriy; Liashenko, Anna; Петраш, Олександр

doi:10.1007/978-3-030-42939-3_64

Cited by 5 publications

(6 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is believed that steel loses its viscoelastic characteristics at a hydrogen content in the range of 7…12 cm 3 /100g [8]. However, as established in [9], hydrogen fragility can occur with a small amount of absorption (absorbed) hydrogen. Thus, in steel with a tensile strength of 1600 MPa, doped with 0.7% Cu, 0.25% Mo, 0.8% Nb and 0.025% Al, a decrease in plastic properties (δ) was observed from 45 to 3% at the level of flooding 0.03 cm 3 /100g.…”

Section: Formulation Of Problems and Relevance Of The Topicmentioning

confidence: 99%

Investigation of mechanical properties and crack resistance parameters of steel reinforcements of reinforced concrete structures of long-term special term

Kulikov¹,

Makarenko²,

Khoruzhiy³

et al. 2021

UWT

Self Cite

View full text Add to dashboard Cite

It is known that the fatigue process begins with the plastic deformation of the surface layers of the metal fittings. Moreover, the displacement of dislocations under conditions of re-alternating loads is observed at loads below the elastic limit of the metal. The rate of local plastic deformation during cyclic deformation is several orders of magnitude higher than the rate of deformation under static loading. Dislocation slip begins in grains with a favorable orientation near stress concentrators. As the number of cycles in the surface layers increases, the density of dislocations and the number of vacancies increases. When the base number of NR cycles is reached, a surface reinforced layer of metal with a large number of germinal cracks is formed, the size of which does not reach a critical value. Increasing the number of cycles cannot cause further development of fracture in such a layer. Only when the stresses exceed the endurance limit of the crack reach a critical length, after which the process of their discharge into the main crack begins with the spread of the latter. The results of experimental studies indicate a strong effect of diffusion hydrogen on static and cyclic parameters of crack resistance. It was found that with increasing flooding, especially when the hydrogen content exceeds 5 cm3/100g, both static strength and long-term strength (fatigue) decrease sharply. Moreover, for these areas of hydrogen solution in reinforcing steel is characterized by a viscous nature of fracture, while for heavily flooded reinforcement (from 5 to 12 cm3/100g is characterized by brittle fracture by the mechanism of microfission in the hardened (martensite or troostite structure). allowed to determine the optimal hydrogen content in reinforcing steel (3…5 cm3 /100g), the excess of which will reduce the crack resistance of reinforcement during long-term operation, especially in corrosive environments. The results of the research confirm the above data. bainite structure y sharply reduces the crack resistance of reinforcing steel, which makes it impossible to use in the manufacture of reinforcement involved in reinforced concrete structures designed for long-term operation (more than 50…60 years). Thus, the obtained diagram can be recommended to designers of reinforced concrete structures for hydraulic purposes, as it greatly facilitates the reasonable choice of reinforcement in the development of reinforced concrete structures for responsible and long-term use.

show abstract

Section: Formulation Of Problems and Relevance Of The Topicmentioning

confidence: 99%

Investigation of mechanical properties and crack resistance parameters of steel reinforcements of reinforced concrete structures of long-term special term

Kulikov¹,

Makarenko²,

Khoruzhiy³

et al. 2021

UWT

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, it should be noted that the absolute values of σtssc should not yet be used in the design of reinforced concrete structures for critical purposes, for example for hydraulic underground structures due to lack of reliable methods for determining and predicting their fatigue (long-term) strength, as they can change and carbon gas and their partial pressures, pH, ambient temperature, process stops, condition of structures, etc.) [4,9,12]. Therefore, in calculations of long-term strength and load-bearing capacity of reinforcing steels of reinforced concrete structures, determining the diameter of reinforcement, the initial parameter may be the minimum allowable value of the yield strength of steel σmin 0.2, and the suitability of structural materials is evaluated by ultimate stresses [10]: ktssc = σtssc/σmin 0.2 (Fig.…”

Section: Skrn Researchmentioning

confidence: 99%

Research of corrosion and mechanical resistance of reinforce-ment steels designated for operation in hydraulic structures

Sukach¹,

Киндрачук²,

Макаренко³

2021

UWT

Self Cite

View full text Add to dashboard Cite

Analytical inspection showed that with a long service life of reinforced concrete structures of hydraulic structures, their individual elements such as reinforcing bars are destroyed due to insufficient fatigue and corrosion strength of the reinforcement metal. They occur mainly under the action of the main variable loads − bending, vibrations of reinforced concrete slabs, mechanical and erosion of the environment. The main causes of failure of the valve are its rupture and wear due to repeated action of force factors. The surface zone of the reinforcement in connection with concrete is especially intensively destroyed due to weak adhesion strength. The use of low-strength reinforcing steels can also be one of the reasons for the failure of reinforcement joints with concrete. Improving the corrosion and mechanical reliability of reinforced concrete structures of hydraulic structures is possible through the use of: for the manufacture of reinforcing bars which are the main power structure of reinforced concrete economically modified alloy steels, which undergo complex heat treatment and are characterized by high corrosion and fatigue properties. alternating) loads; The resistance against SCRN, VIR and corrosion-mechanical fatigue of reinforcing steels intended for the construction industry has been studied. It was found that the experimental steels, economically modified REE, copper-nickel, especially chromium niobium and vanadium meet the requirements of the International Standard NACE MR 0175-96 on chemical composition and mechanical properties, and steels of grades10HSNDA and 20F do not have a sufficiently high resistance SCRN <limits σ0.2min) and corrosion-fatigue failure, and steels of grades 20F and 06G2B showed low resistance to VIR (CLR> 6% and CTR> 3%). Therefore, it is necessary to carry out a full (100%) input control of corrosion and mechanical resistance of all materials involved in the manufacture of reinforced concrete structures for hydraulic purposes for operation in hydrogen sulfide-containing environment.

show abstract

“…It is already known that doping welding connections, made basic type coated electrodes, allowing sufficient effectively regulate the mechanical properties of metals by changing the morphology [1,2,3], distribution and dispersion structural components [4,5,6,7,8,9,10,11], as well as changes in the composition [12,13,14,15] and condition of the grain boundaries [16,17]. Most researchers consider the influence of alloying elements on the properties of metals at single doping [5,6,7].…”

Section: Literature Reviewmentioning

confidence: 99%

“…4a, c). Micro-voids, which merge to form a critical-length binder crack, from which fracture begins, can occur both around non-metallic inclusions and as a result of stratification along the boundaries of ferrite grains [4,8,9,14]. Mechanical testing of the samples showed that the most stable and high toughness values and characteristics of crack resistance of the weld metal boiler steel 20 K are achieved when the concentration of molybdenum in the weld metal within 0.1-0.3%.…”

Section: Fig 7 Non-metallic Inclusions In Fractures Of Specimens Made Of Welds On 20k Steel: A) B) C) -Joints Not Doped With Mo; D) C) -Jmentioning

confidence: 99%

Research of Microstructure of Molybden Doped Weldings of Oil and Gas Pipelines

Pandová

Rimár

Макаренко

et al. 2021

Management Systems in Production Engineering

View full text Add to dashboard Cite

Still existing scientific, technical and technological developments to improve the quality of welded joints of metal pipe structures contain contradictions and uncertainty about the effects of alloying elements, such as molybdenum, mechanical and visco-plastic properties, as well as metallographic component joints. All this indicates the need for a systematic study of these problems for the development of rational metallurgical and technological measures to significantly improve the technological and corrosion-mechanical properties of weld metal. Metallographic studies, using laboratory equipment with high identifying ability, found that the doping of weld metal with molybdenum in the amount of 0.2-0.4% causes fragmentation of ferrite-pearlite structure, including carbides Mn and Fe, and also reduces the number and size of non-metallic inclusions – sulfides, oxides and silicates. Moreover, non-metallic inclusions have a dispersed appearance, which promotes plasticization of the structure, which directly increases the viscous-plastic characteristics and resistance of the metal joints to crack formation. Based on the results of metallographic research, the optimum content in the weld metal of the alloyed element – molybdenum, which is 0.2-0.4%, is determined.

show abstract

Hydrate Formations Modeling for the Oil and Gas Facilities Reconstruction

Cited by 5 publications

References 3 publications

Investigation of mechanical properties and crack resistance parameters of steel reinforcements of reinforced concrete structures of long-term special term

Investigation of mechanical properties and crack resistance parameters of steel reinforcements of reinforced concrete structures of long-term special term

Research of corrosion and mechanical resistance of reinforce-ment steels designated for operation in hydraulic structures

Research of Microstructure of Molybden Doped Weldings of Oil and Gas Pipelines

Contact Info

Product

Resources

About