scholarly journals Material and method selection for increasing the wear resistance of construction machines components

2020 ◽  
Vol 17 (4) ◽  
pp. 464-475 ◽  
Author(s):  
A. P. Scherbakov

Introduction. The article examines the problem of choosing a material and method for increasing the wear resistance of construction machines elements. The performance of construction machines is affected by the reliability of the parts used. The selection of materials for their manufacture allows to calculate the probability of how such elements will affect its ability to work and productivity.Materials and methods. In the process of determining the material and the method for increasing the wear resistance of construction machines, structural steels with various chemical compositions were selected: lowcarbon 08ps (as a model material), 10, 20.30, St3 and low-alloy steels 09G2S and 10HSND, as well as high-carbon steel 65G and boron steel 30MnB5. The methods as high temperature annealing, normalization, injection and high temperature release, thermocyclic processing, cold plastic deformation, thermocyclic processing of steels after cold plastic deformation were used.Results. During the experiment, it was found that both for low-carbon 08ps, 10, 20, 30, St3, and for low-alloy structural steels 09G2S and 10HSND, as well as for high-carbon steel 65G and for boron-containing steel 30MnB5, an increase in the number of TCT cycles (thermal cycling) leads to an increase in the strength properties of the metal. With an increase in the number of cycles over 3-6, the increase in strength properties slows down significantly. Conclusion. In contrast to heat treatment, TCO allows to identify the positive effect of alloying on strength and plastic properties to a greater extent. At the same time, significantly increasing the strength and plasticity, it is possible to obtain previously unattainable values of the work of destruction of alloy steels in the process of various types of loading. Accordingly, the preliminary preparation of steel for the production of individual elements of machines and mechanisms will increase their strength and wear resistance.

2021 ◽  
Vol 4 ◽  
pp. 74-80
Author(s):  
Zhang Yong Jun ◽  
◽  
Li Xin Peng ◽  
Wang Jiu Hua ◽  
Han Jing Tao ◽  
...  

As the object for the study, graphitized high-carbon steel sheet with a carbon content of 0.66 % was used, the tensile test of this sheet using a universal testing (breaking) machine was performed; as well as in-situ observation of the microstructure in the process of tensile deformation of this sheet using in-situ technology of scanning electron microscopy (SEM) was made. The test results show that the main mechanical properties in different directions of tested graphitized high-carbon steel sheet are relatively the same, that is, for a tensile sample of different directions, the ratio of the yield strength σ0,2 to the tensile strength σв is approximately 0.73; the strain hardening index n is approximately 0.24; the plastic deformation coefficient r is approximately 0.83. This indicates that this sheet did not exhibit significant anisotropy. In the process of tensile, deformation of the specimen is mainly developed from local plastic deformation of the graphite inclusions to the total deformation in the deformation zone of the sample; with the increase of displacement, micro-gap between the graphite inclusion and ferrite grain along the direction of the axis of tensile gradually formed and propagated along the direction perpendicular to the axis of tensile; number of slip lines in the ferrite matrix gradually increased, and the distance between them gradually decreases; when the sample breaks, in the fracture large dimple with the core of graphite inclusion and small dimples in the ferrite appears. And the ferrite matrix near the fracture is covered with slip lines, this shows that the ferritic matrix underwent severe plastic deformation before breaking.


Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1618 ◽  
Author(s):  
Zhaohuan Song ◽  
Songhao Zhao ◽  
Tao Jiang ◽  
Junjie Sun ◽  
Yingjun Wang ◽  
...  

In this work, a multiphase microstructure consisting of nanobainte, martensite, undissolved spherical carbide, and retained blocky austenite has been prepared in an Al-alloyed high carbon steel. The effect of the amount of nanobainite on the dry sliding wear behavior of the steel is studied using a pin-on-disc tester with loads ranging from 25–75 N. The results show that, there is no significant differences in specific wear rate (SWR) for samples with various amounts of nanobainite when the normal load is 25 N. While, the SWR firstly decreases and then increases with increasing the amount of nanobainite, and the optimum wear resistance is obtained for samples with 60 vol.% nanobainite, when the applied load increases to 50 and 75 N. The improved wear resistance is attributed to the peak hardness increment resulted from the transformation of retained austenite to martensite, work hardening, along with amorphization and nanocrystallization of the worn surface. In addition, the highest toughness of the samples with 60 vol.% nanobainite is also proven to play a positive role in resisting sliding wear. EDS (energy dispersion spectrum) and XRD (X-ray diffraction) examinations reveal that the predominant failure mechanism is oxidative wear.


2020 ◽  
Vol 975 ◽  
pp. 59-64
Author(s):  
Andrey N. Anikeev ◽  
Ilia V. Chumanov ◽  
Vadim Sedukhin

Study of TiC interaction with low-and high-carbon steel is presented in this article. Was carried out interaction thermodynamic modeling in the temperature range of 900-1800 °C, which showed that titanium carbide would dissolve in melts with these compositions, regardless of melt’s carbon content at given parameters. The obtained thermodynamic results were verified by conducting an experiment with high-temperature complex in order to study substances interaction processes. The obtained experimental samples were studied with scanning microscope as well as structure and compounds composition, obtained as a result of experiment mentioned above.


2012 ◽  
Vol 57 (4) ◽  
pp. 1105-1110 ◽  
Author(s):  
J. Adamczyk ◽  
M. Suliga ◽  
J.W. Pilarczyk ◽  
M. Burdek

In this work the influence of the die approach and bearing part of die on mechanical-technological properties of high carbon steel wires has been assessed. The drawing process of φ5.5 mm wires to the final wire of φ2.9 mm was conducted in 6 passes, by means of a multi-die drawing machine Koch type. The drawing speeds in the last passes were: 7 m/s. For wires drawn according to four variants the investigation of mechanical-technological properties has been carried out, in which yield strength, tensile strength, uniform and total elongation, reduction of area, the number of twists and the number of bends were determined. On the basis of numerical analyses wire drawing process, the influence of geometry of die on redundant strain and effective strain has been determined. The investigations have shown the essential influence of geometry of die on mechanical-technological properties of high carbon steel wires. It has been shown that the increase of strength properties in wires drawn with high die angle is related to the occurrence in their bigger effective strain.


2019 ◽  
Vol 61 (12) ◽  
pp. 995-996
Author(s):  
G. A. Orlov ◽  
Е. N. Shestakova

The article presents high-carbon hypereutectoid steel for production of hot rolling forged rolls. The steel contains 1.2 – 1.4 % of carbon, carbide forming alloying elements Cr, Mo, V and Nb improving  wear  resistance  of  the  rolls,  and  Ni  increasing  hardening  capacity.  It  has  been  found  that  steel  of  proposed  composition  provides  ductility  sufficient  for  hot  deformation  (forging)  by  moderate  single  compressions. Temperature range of ingot deformation has been detected: finite  temperature deformation should not be below 900 °C, forging temperature – 1150 °C. According to its properties steel can be recommended  for manufacturing solid-forged rolls and bandages for composite rolls  of hot rolling from ingots of up to 10 tons weight.


2010 ◽  
Vol 165 ◽  
pp. 371-376 ◽  
Author(s):  
Maciej Suliga

In this work the influence of value of single draft on mechanical-technological properties of high carbon steel wires was evaluated. For wires drawn with medium single draft (10.4 %, 15.5 % and 26.5 %) the investigation of mechanical-technological properties was performed thereby providing results on yield strength, tensile strength, elongation, contraction, number of twist and number of band. On the basis of numerical analysis of wire drawing process the influence of the value of single draft on inhomogeneity of strain was determined. It was established that in the range of medium single drafts 10-26 % used in drawing process of high carbon steel wires large single drafts cause the increase of their strength properties by deterioration of their plasticity properties. It was demonstrated that the increase of strength properties in wires drawn with larger single drafts is related to the occurrence of higher non-dilatational strain, which cause additional work hardening of material. The theoretical-experimental analysis of drawing of high carbon steel wires enabled evaluation of optimal value of single drafts by which it can be used relatively the most advantageous useful properties of wires. Obtained research results can be applied while designing the production process of high carbon steel wires.


1984 ◽  
Vol 106 (3) ◽  
pp. 253-256 ◽  
Author(s):  
J. Lyman

When high carbon, low alloy steels, such as AISI 52100, are conventionally quenched or marquenched from an austenitizing temperature that dissolves all of the carbon in the austenite, many of the martensite crystals in the quenched microstructure are fractured or microcracked. This paper describes a process in which a limited amount of martensite is formed by quenching the steel to a temperature between the Ms temperature and conventional quench temperatures. This martensite is then tempered for a short time to toughen it before again cooling the steel to complete the formation of martensite from austenite. When the limited amount of martensite formed, and intermediately tempered, and the martensite formed on cooling from the intermediate tempering temperature are appropriately balanced by the processing, micro-cracking is essentially avoided. The process can be done in equipment and with procedures commonly used commercially.


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