THE STRUCTURE AND PROPERTIES OF IRON ALLOYS WITH VARIOUS CHEMICAL COMPOSITIONS AFTER DIFFUSIONAL BORONIZING

Tribologia ◽  
2017 ◽  
pp. 65-71 ◽  
Author(s):  
Aleksandra PERTEK-OWSIANNA
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Boride Layer ◽  
Alloying Elements ◽  
Chemical Compositions ◽  
Test Results ◽  
Structure And Properties ◽  
Two Phase ◽  
Phase Layer ◽  
The Core

The purpose of the paper was to test how the content of carbon and alloying elements in steels influence the structure and properties of boronized layers. The following grades of steels were used during the tests: C45, C99U, 41Cr4, 42CrMo4, 45SG, 50HS, 60G, and 102Cr6. In the process of boronizing, the two-phase layer of borides of FeB and Fe2B were obtained on the tested steels with a hardness from 1900 HV0.1 for boride FeB to 1600 HV0.1 for Fe2B, irrespective of the chemical composition of the core/substrate. As the kontent of carbon and alloying elements in steels increase, the structure of borides becomes more compact, and the needles are thicker. The richer in alloying elements the core and the more carbon in steel, the thinner is the boride layer. After boronizing, the layer of FeB and Fe2B with a thickness of approx. 110 μm for C45 steel to approx. 90 μm for 102Cr6 steel was obtained. The test results indicate that the brittleness of borides increases in steels with the addition of Cr, and it decreases in steels containing Si and Mn. The highest wear resistance was obtained in steel 102Cr6.

scholarly journals Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Mark Bediako ◽  
Eric Opoku Amankwah
Keyword(s):  
Chemical Composition ◽  
Portland Cement ◽  
Ordinary Portland Cement ◽  
Chemical Compositions ◽  
Test Results ◽  
Brand Name ◽  
X Ray ◽  
Portland Limestone Cement ◽  
Limestone Cement ◽  
Construction Works

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, and Diamond PLC. The chemical compositions were analyzed with X-Ray Fluorescence (XRF) spectrometer. Student’st-test was used to test the significance of the variation in chemical composition between standard literature values and each of the commercial cement brands. Analysis of variance (ANOVA) was also used to establish the extent of variations between chemical compositions and brand name of the all commercial Portland cement brands. Student’st-test results showed that there were no significant differences between standard chemical composition values and that of commercial Portland cement. The ANOVA results also indicated that each brand of commercial Portland cement varies in terms of chemical composition; however, the specific brands of cement had no significant differences. The study recommended that using any brand of cement in Ghana was good for any construction works be it concrete or mortar formation.

Reduction of oxides formation at surfact depositsitson of wear-resistant alloys

2020 ◽  
Vol 98 (4) ◽  
pp. 45-49
Author(s):  
V Chigarev ◽  
◽  
Yu Logvinov ◽  
Keyword(s):  
Chemical Composition ◽  
Weld Pool ◽  
Ventilation System ◽  
Alloying Elements ◽  
Wear Resistant ◽  
Alloying System ◽  
The Core ◽  
Process Creation ◽  
Deposited Metal ◽  
Oxidative Processes

The article deals with the issues of reducing the content of harmful substances when surfacing alloyed wear-resistant alloys. Studies have been carried out to determine the possibility of reducing the formation of oxides during surfacing of high-alloy wear-resistant alloys of the sormite type using a closed filter-ventilation system, which ensures minimal losses of alloying elements during the formation of the deposited layer. The loss of alloying elements during surfacing is influenced by a number of metallurgical and technological factors, including the share of the base metal in the deposited, surfacing modes, oxidation processes during melting of the electrode material and in the melt of the weld pool when interacting with the surrounding gas environment. To reduce the oxygen content in the gas-air mixture formed during the surfacing process, special absorbent substances are used in a closed filtering and ventilation system, which reduce the course of oxidative processes with the formation of oxides of alloying elements. At the same time, the gas-air mixture is taken from the zone of arc burning and the weld pool, filtered through a system of special filters, in which solid and gaseous components of the welding aerosol are removed, after which the purified gas mixture is used as gas protection during surfacing. We used powder tapes containing a mechanical mixture of powder components and a complex-alloyed alloy in the core. A complex-alloyed alloy, an alloy previously melted in an induction furnace, containing the necessary alloying elements. Particles of the required sizes were obtained by hydrogranulation, which were then introduced into the core of a flux-cored tape. The indicated flux-cored strips provided the same chemical composition of one alloying system in the deposited layer. After surfacing, the chemical composition of the deposited metal was determined for the content of carbon, manganese, silicon, nickel. The use of a closed filtering and ventilation system makes it possible to reduce the formation of oxides of alloying elements, which requires the determination of specific parameters for each surfacing process. Creation and use of closed fil'tro vent system (CFVS), serve of the filtered air in area of surfacing and providing safe labour in the workplace of welder. It corresponds the international standard of ISO and norms of European Union. Therefore, to execute a requirement to impermissibility of hit of harmful questions in an atmosphere concordantly Kiotskomuo and to Parisian protocols.

Research of the composition, structure and properties of deposited alloys of the titanium—aluminum system doped with chrome

2021 ◽  
pp. 470-475
Author(s):  
A.I. Kovtunov ◽  
A.G. Bochkarev
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Heat Resistance ◽  
Titanium Aluminide ◽  
Titanium Aluminides ◽  
Structure And Properties ◽  
Composition And Structure ◽  
Titanium Aluminum ◽  
Composition Structure

The results of the study of the processes of argon-arc surfacing of alloys based on titanium aluminides doped with chromium are presented. The effect of surfacing modes on the chemical composition and structure of the deposited alloys has been established. The results of testing the hardness, wear resistance and heat resistance of chromium-alloyed alloys based on titanium aluminide are presented.

scholarly journals Analysis of the Aroma Chemical Composition of Commonly Planted Kiwifruit Cultivars in China

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1645
Author(s):  
Tian Lan ◽  
Chenxu Gao ◽  
Quyu Yuan ◽  
Jiaqi Wang ◽  
Hexin Zhang ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Chemical Composition ◽  
Internal Standard ◽  
Chemical Compositions ◽  
The Core ◽  
Ethyl Butanoate ◽  
Aroma Chemical ◽  
Aroma Components ◽  
Degree Of Similarity

The aroma chemical composition of commonly planted kiwifruit cultivars in China was analyzed. The combination of 2-octanone with 3-octanone was the most suitable dual internal standard for quantitative analysis in GC-MS. A total of 172 aroma components in 23 kiwifruit cultivars were detected, and ethyl butanoate, (E)-2-hexen-1-ol, and (E)-2-hexenal could be considered the core aroma components in kiwifruit, but still need further confirmation using Sensomics. E-nose could effectively distinguish different cultivars of kiwifruit. Clustering based on GC-MS and E-nose results tends to be consistent and demonstrate a certain degree of similarity. Kiwifruit cultivars with different flesh colors cannot be effectively distinguished by their aroma chemical compositions. Different species of kiwifruit can be distinguished to some extent by their aroma chemical compositions, but the effect was not satisfactory. These results could prove valuable in the breeding, planting, and marketing of kiwifruits.

Investigation of structure and properties of surfaced coatings based on titanium nickelide

2021 ◽  
Vol 4 ◽  
pp. 81-88
Author(s):  
A. I. Kovtunov ◽  
◽  
D. I. Plahotny ◽  
T. V. Semistenova ◽  
A. G. Bochkarev ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Chemical Composition ◽  
Heat Resistance ◽  
Titanium Nickelide ◽  
Nickel Electrode ◽  
Structure And Properties ◽  
Relative Wear ◽  
Relative Wear Resistance

The conditions for formation of coatings based on titanium nickelide under the argon double-arc surfacing of titanium and nickel electrode wires on the titanium samples were shown. Results of evaluating the quality of formation and geometric parameters of the weld at the double-arc surfacing were presented. Relationship between the ratio of feed rates of nickel and titanium wires and chemical composition of the deposited coatings has been established. Investigations of the structure of the surfaced metal at the surfacing modes was carried out. It has been shown that argon double-arc surfacing formed coatings based on the Ti2Ni and TiNi. Mechanical and operational properties of surfaced coatings were studied — hardness, resistance to abrasion and heat resistance at 800 °С. Relative wear resistance of surfaced coatings is higher than that of titanium samples. Dependence of the relative wear resistance of the coatings on the chemical and phase composition was shown. Dependence of heat resistance of the surfaced coatings on the modes of surfacing and the chemical composition of the weld metal is established.

Evaluation of the Role of Alloying Elements in Austemperability of Heavy Section Ductile Iron

2009 ◽  
Vol 83-86 ◽  
pp. 481-487
Author(s):  
M. Heydarzadeh Sohi ◽  
Mahmoud Nili-Ahmadabadi ◽  
A. Bahrami Vahdat ◽  
A. Amirsadeghi
Keyword(s):  
Chemical Composition ◽  
Ductile Iron ◽  
Alloying Elements ◽  
Chemical Compositions ◽  
Ttt Diagram ◽  
Heavy Section ◽  
Hardness Tests ◽  
Pearlitic Transformation ◽  
Bainitic Structure

In this investigation the role of alloying elements on austemperability of heavy section ductile irons was studied. Four different chemical compositions were chosen in a way to specify an optimal chemical composition with suitable austemperability. Austempering was carried out at 315 and 350oC for 1 hour on specimens prepared from cast Y-blocks with 75 mm thickness. Metallographic examinations and hardness tests indicated that thickness of bainitic layer was positively dependant on the amount of the alloying elements which deferred pearlitic transformation in TTT diagram to the longer time. In addition, by increasing the amount of alloying elements, the morphologies of ferrite in bainitic structure changed from featherlike to acicular. According to the results of this study, in order to achieve a full bainitic structure (in the specimens whit 75mm thickness), the optimal amounts of alloying elements were: 0.35 % Mn, 0.22 % Mo, 1.1-1.4% Ni and 0.6% Cu. In addition, regarding to the thick sections of Y-blocks, graphite degeneration defect was also studied, and it was noticed that this defect could be completely eliminated by adding 50ppm of antimony.

Wear Resistance of Steels after Diffusion Saturation of Boron, Chrome and Titanium

2019 ◽  
Vol 298 ◽  
pp. 75-80
Author(s):  
Aleksey Guriev ◽  
Michail Alekseevich Guriev ◽  
Sergei Gennadievich Ivanov ◽  
Yan Wei Zhang ◽  
Shun Qi Mei
Keyword(s):  
Wear Resistance ◽  
Economic Effect ◽  
Total Content ◽  
Diffusion Saturation ◽  
Alloying Elements ◽  
Test Results ◽  
Mass Percent ◽  
Loss Of Mass ◽  
The Cost ◽  
Fixed Abrasive

In this work, the wear resistance of hardened simultaneous diffusion saturation on S235J0, C45, 55NiCrMoV6, C80W1 and X162CrMoV12 steels with boron, chromium and titanium and rigidly fixed abrasive Al2O3 particles were investigated. Wear was determined by measuring the loss of mass every 30 seconds of the test. Full wear of the layer occurred in 10 minutes with a load on the sample of 9.5 MPa. According to the test results, it is found that the wear resistance of alloyed steels increases as the content of alloying elements and carbon increases, but this increase is not unambiguous because of a decrease in the thickness of the diffusion layer as the degree amplification of alloying steels. Taking into account the economic parameters, such as the cost of steel, the cost of manufacturing products, we can conclude that the greatest economic effect shape can be achieved when using the hardening steels with a carbon content of 0.5 mass percent and the total content of alloying elements up to 5 - 7 mass percent.

scholarly journals Reduction of Oxides Formation During Surfacing of Wear-resistant Alloys

2020 ◽  
pp. 43-47
Author(s):  
Valeriy Chigarev ◽  
◽  
Yuriy Logvinov ◽  
Alexandr Belik ◽  
◽  
...  
Keyword(s):  
Chemical Composition ◽  
Weld Pool ◽  
Ventilation System ◽  
Alloying Elements ◽  
Wear Resistant ◽  
Alloying System ◽  
The Core ◽  
Deposited Metal ◽  
Oxidative Processes

The article deals with the issues of reducing the content of harmful substances when surfacing alloyed wear-resistant alloys. Studies have been carried out to determine the possibility of reducing the formation of oxides during surfacing of high-alloy wear-resistant alloys of the sormite type using a closed filter-ventilation system, which ensures minimal losses of alloying elements during the formation of the deposited layer. The loss of alloying elements during surfacing is influenced by a number of metallurgical and technological factors, including the share of the base metal in the deposited, surfacing modes, oxidation processes during melting of the electrode material and in the melt of the weld pool when interacting with the surrounding gas environment. To reduce the oxygen content in the gas-air mixture formed during the surfacing process, special absorbent substances are used in a closed filtering and ventilation system, which reduce the course of oxidative processes with the formation of oxides of alloying elements. At the same time, the gas-air mixture is taken from the zone of arc burning and the weld pool, filtered through a system of special filters, in which solid and gaseous components of the welding aerosol are removed, after which the purified gas mixture is used as gas protection during surfacing. We used powder tapes containing a mechanical mixture of powder components and a complex-alloyed alloy in the core. A complex-alloyed alloy, an alloy previously melted in an induction furnace, containing the necessary alloying elements. Particles of the required sizes were obtained by hydrogranulation, which were then introduced into the core of a flux-cored tape. The indicated flux-cored strips provided the same chemical composition of one alloying system in the deposited layer. After surfacing, the chemical composition of the deposited metal was determined for the content of carbon, manganese, silicon, nickel. The use of a closed filtering and ventilation system makes it possible to reduce the formation of oxides of alloying elements, which requires the determination of specific parameters for each surfacing process.

scholarly journals Development of heat treatment modes for a two-phase titanium alloy to form regulated structure and properties complex

2019 ◽  
Vol 298 ◽  
pp. 00049
Author(s):  
Svetlana Skvortsova ◽  
Galina Gurtovaya ◽  
Maria Afonina ◽  
Natalya Ruchina ◽  
Gulnara Zaynetdinova
Keyword(s):  
Heat Treatment ◽  
Titanium Alloy ◽  
Chemical Composition ◽  
Structure And Properties ◽  
Two Phase ◽  
Hot Rolled

The article shows the possibility of creating structure of the same type and, accordingly, a close level of properties in hot-rolled semi-finished products of the VST2K alloy with different chemical composition by means of heat treatment.

Influence of Ultrasonic on the Microstructure and Properties of Electroless Plating Ni-Co-P Coating at Low Temperature

2011 ◽  
Vol 314-316 ◽  
pp. 259-262
Author(s):  
Hua Sun ◽  
Xiao Fei Guo ◽  
Ke Gao Liu ◽  
Hong Fang Ma ◽  
Li Ming Feng
Keyword(s):  
Crystal Structure ◽  
Wear Resistance ◽  
Rare Earth ◽  
Chemical Composition ◽  
Diffraction Peak ◽  
Chemical Compositions ◽  
Fine Crystal ◽  
X Ray ◽  
Energy Spectrometer ◽  
Electroless Ni

By electron energy spectrometer,X-ray diffractometer,transmission elec-tron microscopy andmicro-hardometer,the depositing speed of electrolessNi-Co-P plating baths,chemical composition,crystal structure and microhardness of the alloy coatings were inspected and analyzed with ultrasonic and rare earth metalcerium intervening in electroless Ni-Co-P plating•The results show that the depositing speed of electroless Ni-Co-P plating isobviously increased under the effect of ultrasonic.The chemical compositions of electroless Ni-Co-P plating are changed，The XRD of coating has a diffuse sexual diffraction peak closing to typical amorphous structure.the obtained Ni-Co-P coating has more fine crystal grain, even and dense surface morphology. Its wear resistance and hardness have been improved obviously.

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