scholarly journals INFLUENCE OF PLASTIC DEFORMATION CARBON STEEL ON THE PROCESS OF BURNING ELECTRIC ARC

Author(s):  
Igor Alex VAKULENKO ◽  
Sergey PLITCHENKO ◽  
Bulent KURT ◽  
Hangardas ASKEROV ◽  
Svetlana PROYDAK ◽  
...  

During a study of the combustion process of a direct polarity electric arc, a directly proportional dependence of the electric current value on the degree of cold plastic deformation of carbon steel used as an electrode was found. To calculate the value of the electric current during arc burning, in the indicated ratio, it was proposed to replace the surface tension force of the liquid metal with the surface tension of ferrite of plastically deformed carbon steel. Calculation of the ferrite’s surface tension value on the deformation degree of the steel under study through the size of the coherent scattering regions was used to explain the observed dependence of the electric current during arc burning. From the analysis of the considered correlation ratios, it was found that with an increase in the cold deformation degree, the refinement of the coherent scattering regions results in the ferrite’s surface tension increase and consequently, to an increase in the electric current during arc burning. Comparative analysis of the obtained results of calculating the value of electric current during arc burning through the surface tension of ferrite of cold-deformed carbon steel showed a fairly good coincidence with experimental data. The differences did not exceed 9%.

2017 ◽  
Vol 62 (1) ◽  
pp. 223-230 ◽  
Author(s):  
A. Szkliniarz

Abstract This paper presents the possibilities of forming the microstructure as well as mechanical properties and electrical conductivity of Cu-3Ti alloy (wt.%) in thermal and thermomechanical processes that are a combination of homogenising treatment, hot and cold working, solution treatment and ageing. Phase composition of the alloy following various stages of processing it into the specified semi-finished product was being determined too. It was demonstrated that the application of cold plastic deformation between solution treatment and ageing could significantly enhance the effect of hardening of the Cu-3Ti alloy without deteriorating its electrical conductivity. It was found that for the investigated alloy the selection of appropriate conditions for homogenising treatment, hot and cold deformation as well as solution treatment and ageing enables to obtain the properties comparable to those of beryllium bronzes.


2015 ◽  
Vol 56 (9) ◽  
pp. 57
Author(s):  
D. O. Panov ◽  
A. N. Balakhnin ◽  
A. S. Perzev ◽  
A. I. Smirnov ◽  
M. Y. Simonov

2007 ◽  
Vol 353-358 ◽  
pp. 575-578
Author(s):  
Bin Xu ◽  
Le Yang ◽  
Shi Bo Xing ◽  
Li Li

In order to increase boronizing speed without decreasing the hardness of boride layer, the effect of plastic deformation at room temperature on powder RE-chrome-boronizing for a medium carbon steel (steel 45), in which boronizing plays a main role, was studied in this paper. The cold plastic deformation (CPD), whether compressing or shot-peening, can increase boronizing speed. Meanwhile, the boride layer can also retain its high microhardness (1 300―1 900HV0.1) with low brittleness. The layer depth achieved for a given heating time increases with increasing CPD degree on the steel. The analyses show that boronizing kinetics in the RE-chrome-boronizing (RE-Cr-B) samples with CPD can be enhanced.


Author(s):  
І. О Vakulenko ◽  
D. M Bolotova ◽  
S. V Proidak ◽  
B Kurt ◽  
A. E Erdogdu ◽  
...  

Purpose. The aim of this work is to assess the effect of ferrite grain size of low-carbon steel on the development of strain hardening processes in the area of nucleation and propagation of deformation bands. Methodology. Low-carbon steels with a carbon content of 0.06–0.1% C in various structural states were used as the material for study. The sample for the study was a wire with a diameter of 1mm. The structural studies of the metal were carried out using an Epiquant light microscope. Ferrite grain size was determined using quantitative metallographic techniques. Different ferrite grain size was obtained as a result of combination of thermal and termo mechanical treatment. Vary by heating temperature and the cooling rate, using cold plastic deformation and subsequent annealing, made it possible to change the ferrite grain size at the level of two orders of magnitude. Deformation curves were obtained during stretching the samples on the Instron testing machine. Findings. Based on the analysis of stretching curves of low-carbon steels with different ferrite grain sizes, it has been established that the initiation and propagation of plastic deformation in the jerky flow area is accompanied by the development of strain hardening processes. The study of the nature of increase at dislocation density depending on ferrite grain size of low-carbon steel, starting from the moment of initiation of plastic deformation, confirmed the existence of relationship between the development of strain hardening at the area of jerky flow and the area of parabolic hardening curve. Originality. One of the reasons for decrease in Luders deformation with an increase of ferrite grain size of low-carbon steel is an increase in strain hardening indicator, which accelerates decomposition of uniform dislocations distribution in the front of deformation band. The flow stress during initiation of plastic deformation is determined by the additive contribution from the frictional stress of the crystal lattices, the state of ferrite grain boundaries, and the density of mobile dislocations. It was found that the size of dislocation cell increases in proportion to the diameter of ferrite grain, which facilitates the development of dislocation annihilation during plastic deformation. Practical value. Explanation of qualitative dependence of the influence of ferrite grain size of a low-carbon steel on the strain hardening degree and the magnitude of Luders deformation will make it possible to determine the optimal structural state of steels subjected to cold plastic deformation.


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.


Sign in / Sign up

Export Citation Format

Share Document