Technical condition of welded load-bearing metal structures of operated agricultural hoisting cranes

The paper considers the methodology for assessing the technical condition of welded load-bearing metal structures of operated agricultural hoisting cranes. In the course of the study, the relationship between structural, mechanical and magnetic parameters was established during cyclic elastic-plastic deformation of low-carbon and low alloy steels. Based on the analysis, it was concluded that the dependence of the minimum values of the magnetic parameter on the acting stresses Нр(σ) is influenced by the metal structure and its chemical composition. It has been established that the coarser-grained structure of the studied steels under elastic-plastic deformation contributes to a shift in the minimum values of Нр towards lower acting stresses; an increase in the strength characteristics of steels shifts the minimum of Нр toward large values of s, which must be taken into account when conducting technical diagnostics of the elements of the operating metal structures of hoisting cranes. Based on the results of the study, a method for determining the acting stresses in the elements of the metal structures of hoisting cranes was developed, which, by the nature and magnitude of the change in the residual magnetization of the scattering field during their stepwise loading (unloading), allows judging the magnitude of the acting stresses. The work also presents a methodology for assessing the technical condition of welded load-bearing metal structures of hoisting cranes based on the integrated use of passive flux-gate and other control methods, which allows determining the acting stresses used in strength calculations in the identified hazardous zones of concentration of stresses in the elements of metal structures.

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Ultrastrong low-carbon nanosteel produced by heterostructure and interstitial mediated warm rolling

Science Advances ◽

10.1126/sciadv.aba8169 ◽

2020 ◽

Vol 6 (39) ◽

pp. eaba8169 ◽

Cited By ~ 1

Author(s):

Bo Gao ◽

Qingquan Lai ◽

Yang Cao ◽

Rong Hu ◽

Lirong Xiao ◽

...

Keyword(s):

Energy Efficiency ◽

Plastic Deformation ◽

Scaling Up ◽

Warm Rolling ◽

Low Alloy Steels ◽

Dual Phase ◽

Low Carbon ◽

Ultrahigh Strength ◽

Alloy Steels ◽

Deformation Compatibility

Ultrastrong materials can notably help with improving the energy efficiency of transportation vehicles by reducing their weight. Grain refinement by severe plastic deformation is, so far, the most effective approach to produce bulk strong nanostructured metals, but its scaling up for industrial production has been a challenge. Here, we report an ultrastrong (2.15 GPa) low-carbon nanosteel processed by heterostructure and interstitial mediated warm rolling. The nanosteel consists of thin (~17.8 nm) lamellae, which was enabled by two unreported mechanisms: (i) improving deformation compatibility of dual-phase heterostructure by adjusting warm rolling temperature and (ii) segregating carbon atoms to lamellar boundaries to stabilize the nanolamellae. Defying our intuition, warm rolling produced finer lamellae than cold rolling, which demonstrates the potential and importance of tuning deformation compatibility of interstitial containing heterostructure for nanocrystallization. This previously unreported approach is applicable to most low-carbon, low-alloy steels for producing ultrahigh strength materials in industrial scale.

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The influence of grain boundaries on the development of deformation in low-carbon low-alloy steels

Physical Metallurgy and Heat Treatment of Metals ◽

10.30838/j.pmhtm.2413.270421.55.741 ◽

2021 ◽

pp. 55-63

Author(s):

Yu.S. Slupska ◽

L.M. Dadiverina ◽

D.Yu. Chashyn ◽

H.O. Toropchenov ◽

M.O. Pyko

Keyword(s):

Plastic Deformation ◽

Grain Boundaries ◽

Alloy Steel ◽

Low Alloy Steels ◽

Low Carbon ◽

Low Alloy Steel ◽

Defective Structure ◽

Urgent Task ◽

Alloy Steels ◽

Kinetics Of

Problem statement. Most modern materials have a polycrystalline structure. Their most important property − mechanical strength − is determined by the defective structure of the crystals. Under the defective structure should be understood not only the concentration and distribution of point defects, dislocations, packaging defects, but also the grain boundaries. The development of such processes as diffusion, recrystallization, plasticity, creep, fragility, cracking and corrosion resistance depends on the grain boundaries. The degree of this influence is directly related to the peculiarities of the atomic structure of boundaries and their interaction with other defects. Therefore, the study of the influence of interfacial and intraphase boundaries on the development of plastic deformation in modern materials is an urgent task. Purpose of the article. Investigation of the influence of the type of polycrystalline boundaries on the kinetics of propagation of plastic deformation in low-carbon low-alloy steel 06Х1. Conclusion. Investigation of the influence of the type of polycrystalline boundaries on the kinetics of propagation of plastic deformation in low-carbon low-alloy steel 06Х1. Conclusion. For low-carbon low-alloy steel 06Х1 the influence of the type of polycrystalline boundaries on the kinetics of plastic deformation propagation is investigated. The relationship between the propagation of plastic deformation and the type of interfacial and intraphase boundaries is established. The proposed physical model takes into account the ability of structural components to block plastic deformation. Keywords: propagation of plastic deformation; boundaries of a special type; boundaries of a general type

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Recent Aspects on the Effect of Inclusion Characteristics on the Intragranular Ferrite Formation in Low Alloy Steels: A Review

High Temperature Materials and Processes ◽

10.1515/htmp-2016-0175 ◽

2017 ◽

Vol 36 (4) ◽

pp. 309-325 ◽

Cited By ~ 19

Author(s):

Wangzhong Mu ◽

Pär Göran Jönsson ◽

Keiji Nakajima

Keyword(s):

Heat Affected Zone ◽

Low Alloy Steels ◽

Low Carbon ◽

Intragranular Ferrite ◽

Metallic Inclusions ◽

Theoretical Investigations ◽

Alloy Steels ◽

Institute Of Technology ◽

Future Work

AbstractIntragranular ferrite (IGF), which nucleates from specific inclusion surfaces in low alloy steels, is the desired microstructure to improve mechanical properties of steel such as the toughness. This microstructure is especially important in the coarse grain heat affected zone (CGHAZ) of weldments. The latest review paper focusing on the role of non-metallic inclusions in the IGF formation in steels has been reported by Sarma et al. in 2009 (ISIJ int., 49(2009), 1063–1074). In recent years, large amount of papers have been presented to investigate different issues of this topic. This paper mainly highlights the frontiers of experimental and theoretical investigations on the effects of inclusion characteristics, such as the composition, size distribution and number density, on the IGF formation in low carbon low-alloyed steels, undertaken by the group of Applied Process Metallurgy, KTH Royal Institute of Technology. Related results reported in previous studies are also introduced. Also, plausible future work regarding various items of IGF formation is mentioned in each section. This work aims to give a better control of improving the steel quality during casting and in the heat affected zone (HAZ) of weldment, according to the concept of oxide metallurgy.

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An Investigation on Boron-Treated Steels (6th Report) On the Effects of Boron-Addition to Low-Carbon, Low-Alloy Steels (III)

Journal of the Japan Institute of Metals and Materials ◽

10.2320/jinstmet1952.17.8_402 ◽

1953 ◽

Vol 17 (8) ◽

pp. 402-407

Author(s):

Yûnoshin Imai ◽

Hikotarô Imai

Keyword(s):

Low Alloy Steels ◽

Boron Addition ◽

Low Carbon ◽

Alloy Steels

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STUDY OF RESIDUAL RESOURCE AND ESTABLISHMENT OF THE LIMIT LIFE OF NON-PURCHASER PASSENGER CARS OF CONSTRUCTION OF KVZ

Collection of scientific works of the State University of Infrastructure and Technologies series Transport Systems and Technologies ◽

10.32703/10.32703/2617-9040-2020-36-6 ◽

2020 ◽

pp. 54-62

Author(s):

N. Radkevich ◽

S. Sapronova ◽

V. Tkachenko

Keyword(s):

Service Life ◽

Residual Life ◽

Rolling Stock ◽

Technical Diagnostics ◽

Passenger Cars ◽

Load Bearing ◽

Metal Structures ◽

Passenger Traffic ◽

Long Operation ◽

Theoretical Results

In order to ensure the uninterrupted performance of passenger traffic, the task of ensuring the operation of rolling stock outside the extended service life, including passenger cars for the carriage of passengers, remains relevant. Based on this, there is a need for comprehensive research aimed at substantiating the possibility of ensuring operation while maintaining dynamic and strength characteristics. The article examines the residual life of load-bearing metal structures of passenger cars based on the results of technical diagnostics and standard tests. It is concluded that the condition of the load-bearing metal structures of passenger cars built by the Kryukiv Carriage Plant (KСP) after long operation does not approach the limit. The obtained practical and theoretical results make it possible to extend the service life of passenger cars for the construction of KCP beyond the factory set by 41 years.

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