scholarly journals High technology to reduce hydrogen wear of work surfaces of friction

2016 ◽  
Vol 1 (10) ◽  
pp. 3-6 ◽  
Author(s):  
Михаил Шалыгин ◽  
Mikhail Shalygin

This paper reports the problems considered regarding the hydrogen wear decrease in steel parts operating in hydrogen medium and, in particular, in hydrocarbon liquids. The comparative researches are carried out with samples after thermal treatment, high-vacuum annealing and ionic implantation and also after a combination of these methods. The structure of samples surface layer is investigated after a combined working and the values of micro-hardness of layers formed are given. The investigation of surface quality changes is carried out. The results of comparative abrasion tests of samples are presented. It is defined that after a combined working samples wear decreased. There are shown data on the hydrogen concentration in a surface layer of samples and the analysis of surface properties for hydrogen concentration and hydrogen wear intensity is carried out.

Author(s):  
Анатолий Суслов ◽  
Anatoliy Suslov ◽  
Михаил Шалыгин ◽  
Mikhail Shalygin

On based on the analysis of the possibility of hardening of steel 40x13 comprehensive treatment to a depth of 4.2 mm. the results of tests on the resistance to fracture and wear. Presents results of a study of hardness and micro geometry of the surface layer of samples. Comprehensive treatment, consisting of thermal and mechanical treatments, high-vacuum annealing and diffusion silicon may become a promising direction to increase the service life of steel parts


2016 ◽  
Vol 1 (7) ◽  
pp. 10-13 ◽  
Author(s):  
Михаил Шалыгин ◽  
Mikhail Shalygin

This paper reports the problems of hydrogen wear decrease in steel parts operating in hydrogen medium. The friction couples of particular machine parts subjected to hydrogen wear are shown. Steel grades of the samples analyzed and their hardness are pointed out. The technologies of high- vacuum annealing and ion implantation used in investigations are de-scribed. The modes for the carrying out of high-vacuum annealing and ion implantation of silicon into a surface of the samples investigated are presented. It is determined that in a surface layer after the carrying out of high-vacuum annealing and ion implantation appear new structures with their form similar to roundish spots. The dimensions of spots and their distribution according to depth are defined. The sample breaking tests are carried out. It is established that technological operations carried out affect only the surface layers of samples. The investigation results can be used at the analysis of methods for hydrogen wear decrease of parts operating in hydrogen medium.


2021 ◽  
Vol 316 ◽  
pp. 794-802
Author(s):  
Andrey E. Balanovsky ◽  
Van Trieu Nguyen

The Purpose of paper is to conduct studies to assess the possibility of increasing the hardness of the surface layer of steel St3 grade by plasma heating of the applied surface coating containing powder alloy PR-N80X13S2R. Mixtures of pasta were divided into 2 groups: for furnace chemical-thermal treatment and plasma surface melting. The study of the microstructure showed a difference in the depth of the saturated layer, depending on the processing method, during chemical-thermal treatment-1 mm, plasma fusion - 2 mm. The results of measuring the surface micro-hardness showed that, the obtained coating from a mixture of PR-N80X13S2R + Cr2O3 + NH4Cl has a uniform high surface hardness (31-64 HRC), from a mixture of only PR-N80X13S2R - the surface hardness varies in a wide range (15-60 HRC). The study of the microhardness of the cross section of the surface layer showed that, the diffusion region: from a mixture of powder PR-N80X13S2R + Cr2O3 + NH4Cl has uniform hardness (450-490 HV); from a mixture of PR-N80X13S2R - hardness increases in the depth of the molten region (from 300 to 600 HV), and sharply decreases in the heat affected zone (210-170 HV). The use of PR-N80X13S2R alloy powder as the main component in the composition of the paste deposited on the St3 surface during plasma treatment leads to the formation of a doped surface layer with high hardness.


Author(s):  
Андрей Киричек ◽  
Andrey Kirichek ◽  
Дмитрий Соловьев ◽  
Dmitriy Solovyev ◽  
Александр Хандожко ◽  
...  

The problems of analyzing metallographic images and the method of their solution using modern software for the analysis of metallographic images are described. There is given an analysis of microstructure images as the main indicator of the surface layer quality by the example of studying the research results of strain wave hardening combinations and chemical-thermal treatment, in particular the influence of previous strain wave hardening and subsequent thermal and chemical- thermal treatment on the alloy steel microstructure or previous thermal and chemical- thermal treatment and subsequent strain wave hardening. On the basis of the analysis the effectiveness of strain wave hardening and chemical and thermal treatment is established.


Author(s):  
Владимир Макаров ◽  
Vladimir Makarov ◽  
Наталья Ворожцова ◽  
Natalia Vorozhtsova ◽  
Александр Горбунов ◽  
...  

The investigation results of technological potentialities in the finish gear grinding of a ring gear of cylindrical wheels with the combined grinding-polishing worm disk with the assurance of geometrical accuracy and quality parameters of a surface layer are shown. The comparative results of experimental investigations of the structure of surface micro-hardness, its depth and surface residual stresses at cog-wheels finish processing with gear honing and gear polish are given.


2021 ◽  
Vol 2086 (1) ◽  
pp. 012200
Author(s):  
P Palkanov ◽  
V Koshuro ◽  
A Fomin

Abstract The study results of the structure and microhardness of the surface layer of high-speed tool steel after induction chemical-thermal treatment in a gaseous nitrogen-containing medium at a temperature of 900–1100 °C were presented. Due to the strengthening treatment of products a gradient diffusion nitride layer with a thickness of about 200 μm and a surface microhardness of 1950±70 HV1 98 was formed.


Author(s):  
Zhetcho Doinov Kalitchin ◽  
Mara Krumova Kandeva ◽  
Yana Petrova Stoyanova

This research work studies the characteristics of wear and wear resistance of composite powder coatings, deposited by high-velocity oxygen fuel, which contain composite mixtures Ni-Cr-B-Si having different chromium concentrations – 9.9%; 13.2%; 14%; 16% and 20% , at one and the same size of the particles and the same content of the remaining elements. The coating of 20% Cr does not contain B and Si. Out of each powder, composite coatings have been prepared without any preliminary thermal treatment of the substrate and with preliminary thermal treatment of the substrate up to 650оС. The coatings have been tested under identical conditions of dry friction over a surface of solid firmly attached abrasive particles using the tribological testing device „Pin-on-disk“. Results have been obtained and the dependences of the hardness, mass wear, intensity of the wearing process, absolute and relative wear resistance on the Cr concentration under identical conditions of friction. It has been found out that for all the coatings the preliminary thermal treatment of the substrate leads to a decrease in the wear intensity. Upon increasing Cr concentration the wear intensity diminishes and it reaches minimal values at 16% Cr. In the case of coatings having 20% Cr concentration, the wear intensity is increased, which is due to the absence of the components B and Si in the composite mixture, whereupon no inter-metallic structures are formed having high hardness and wear resistance. The obtained results have no analogues in the current literature and they have not been published by the authors.


2000 ◽  
Vol 6 (S2) ◽  
pp. 750-751
Author(s):  
David C Joy ◽  
David Braski

It has been estimated that more than 90% of all scanning electron microscope (SEM) images ever published have been obtained using secondary electrons (SE) which are defined as being those electrons emitted with energies between 0 and 50eV. The properties of these secondary electron are therefore of considerable interest and importance. However, although secondary electrons have been intensively studied since their discovery by Starke in 1901 the majority of the work has been aimed at determining the SE yield coefficient and its variation with energy for elements and compounds. The energy spectrum of secondary electrons has received far less attention although it is evident that the form of the spectrum must have an effect on the image contrast observed in the SEM because SE detectors are energy selective devices. The few studies that have been made have mostly concentrated on spectra obtained from clean samples observed under ultra-high vacuum conditions. This is understandable, because it is certain that the presence of a surface layer of contamination will change the SE spectrum to some degree or other, but it is unfortunate because all specimens in real SEMs are dirty and it is information about this situation that is required.


2012 ◽  
Vol 529-530 ◽  
pp. 574-579
Author(s):  
Tamiye Simone Goia ◽  
Kalan Bastos Violin ◽  
José Carlos Bressiani ◽  
Ana Helena de Almeida Bressiani

Titanium and its alloys are the main metals studied as porous metallic implants by their excellent mechanical properties and biological interactions. Production methods of porous metallic materials are based on powder metallurgy (PM), because it allows the manufacturing of parts with complex shapes and dimensions close to the finals (near-net shape), and the addition of alloying elements reaching a satisfactory structural homogeneity, and porosity. The pore production by space-holder technique constitutes of mixing organic compounds with metal powder, which when removed by thermal treatment prior structures are kept in place. The objective of this study is to obtain porous implants of commercially pure titanium (cpTi) and Ti-13Nb-13Zr alloy by PM with space-holder technique and albumin as an additive. For the processing of the samples were used hydride titanium powder (TiH2) to obtain cpTi samples, and metal powders of Ti, Nb and Zr in the stoichiometric proportions for obtaining the alloy samples. The samples were prepared by mixing the metallic powder to the albumin (30wt%) and filling a silicone model that was pressed isostatically (140 MPa). The thermal treatment was performed in an oxidizing atmosphere (350°C/1h) for the decomposition of organic material. The sintering was performed at a temperature of 1300°C (1h/cpTi, 3h/Alloy) in high vacuum furnace (10-5 mBar) to all samples. The calculated porosity showed a significant difference between the samples cpTi (40%) and alloy (60%). The samples surface characterization showed very rough with high specific surface area. Samples of cpTi presented formation of necks arising from sintering. In the alloy samples were observed homogenous microstructure with the presence of α and β phases composing the Widmanstätten structure. It is possible to conclude that the same amount albumin allowed the formation of pores in the microstructure of cpTi and alloy although in different proportions, without harming the sintering of both and allowing diffusion of the alloy elements.


2012 ◽  
Vol 445 ◽  
pp. 595-600 ◽  
Author(s):  
Ali Shamsipur ◽  
Seyed Farshid Kashani-Bozorg ◽  
Abbas Zarei Hanzaki

In the present investigation, the surface of a commercially pure titanium (CP-Ti) substrate was modified to Ti/SiC nanocomposite layer employing friction stir processing technique; nanosized SiC powder was introduced into the stir zone provided by a rotating and advancing tool. The fabricated nanocomposite surface layer exhibited a micro hardness value of ~535HV which is much greater than 160HV of the substrate material using Vickers micro hardness testing. In addition, the un-treated CP-Ti substrate showed sever wear regime in the pin-on-disc test against the hardened AISI 52100 steel. It suffers extensive typical adhesive wear dominated by plastic deformation as evidenced by scanning electron microscopy. Also, deep grooves were formed, i.e. evidence of abrasive wear. Contrary to this, enhanced wear properties were detected for the Ti/SiC nanocomposite surface layer, i.e. lower coefficient of friction and weight loss. The nanocomposite surface layer was found to be adherent to the underlying substrate during the pin-on-disc test. The superior wear behavior of the nanocomposite surface layer is attributed to its improved micro hardness value due to the presence of hard nanosize SiC particles in a refined titanium matrix.


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