scholarly journals Study of Diffusion Boride Bayers of Steel 20, Obtained by the Micro-Arc Surface

2020 ◽  
pp. 59-63
Author(s):  
E.P. Shevchuk ◽  
V.A. Plotnikov ◽  
G.S. Bektasova
Keyword(s):  
Boric Acid ◽  
Diffusion Zone ◽  
Composite Layer ◽  
High Hardness ◽  
High Strength ◽  
Heterogeneous Structure ◽  
Diffusion Coatings ◽  
The Matrix ◽  
Diffusion Boriding ◽  
Steel 20

We discuss the results of the study of carbon steel 20 boriding performed by the micro-arc chemical-thermal treatment of a mixture containing iron and boric acid. The study has been carried out in scientific laboratories of the EKSU named after S. Amanzholov. It is found out that boride diffusion coatings obtained by this method are characterized by high hardness of 3.5 GPa and have an extensive diffusion zone. The wide diffusion zone is a surface layer of steel in which the compounds of boron and iron are distributed so that a transition region is formed between the hardened region and the matrix. The material of the diffusion zone is a composite consisting of a plastic а-phase of iron and high strength iron borides. X-ray diffraction studies revealed the formation of Fe3B compounds. It is found that the most optimal composition of the mixture contains iron and boric acid in a ratio of 1:3 (Fe-25% + H3BO3-75 %). The use of the micro-arc surfacing method makes it possible to intensify the process of diffusion boriding in comparison with traditional methods. Also, it ensures that a hardened composite layer with a heterogeneous structure formed by the diffusion-crystallization mechanism is developed on a surface of steel products.

Properties of aluminum metal matrix composites manufactured by selective laser melting

2021 ◽  
Vol 112 (7) ◽  
pp. 552-564
Author(s):  
Christian Felber ◽  
Florian Rödl ◽  
Ferdinand Haider
Keyword(s):  
Additive Manufacturing ◽  
Aluminum Alloys ◽  
Selective Laser Melting ◽  
Metal Matrix ◽  
High Hardness ◽  
High Strength ◽  
Laser Melting ◽  
Scanning Calorimetry ◽  
Particle Reinforcement ◽  
The Matrix

Abstract The most promising metal processing additive manufacturing technique in industry is selective laser melting, but only a few alloys are commercially available, limiting the potential of this technique. In particular high strength aluminum alloys, which are of great importance in the automotive industry, are missing. An aluminum 2024 alloy, reinforced by Ti-6Al-4V and B4C particles, could be used as a high strength alternative for aluminum alloys. Heat treating can be used to improve the mechanical properties of the metal matrix composite. Dynamic scanning calorimetry shows the formation of Al2Cu precipitates in the matrix instead of the expected Al2CuMg phases due to the loss of magnesium during printing, and precipitation processes are accelerated due to particle reinforcement and additive manufacturing. Strong reactions between aluminum and Ti-6Al-4V are observed in the microstructure, while B4C shows no reaction with the matrix or the titanium. The material shows high hardness, high stiffness, and low ductility through precipitation and particle reinforcement.

scholarly journals Boron Diffusion in Steel 20

2020 ◽  
pp. 58-62
Author(s):  
E.P. Shevchuk ◽  
V.A. Plotnikov ◽  
G.S. Bektasova
Keyword(s):  
Liquid Glass ◽  
High Hardness ◽  
Ammonium Hydroxide ◽  
Boride Layer ◽  
Boron Diffusion ◽  
Volumetric Heating ◽  
High Refractoriness ◽  
The Matrix ◽  
Steel 20 ◽  
Diffusion Mass

As is known, boriding is carried out to increase the wear resistance and corrosion resistance of iron-carbon alloys. Along with high hardness, borides, unfortunately, have very high fragility and high refractoriness. An effective way to counter the fragility of boride layers is to form a composite structure consisting of inclusions of solid borides in a more plastic matrix. Such coatings can be obtained by volumetric heating in a muffle furnace using a boron paste that besides a mixture of iron and boron powders contained ammonium hydroxide and activated carbon with or without liquid glass. Boriding of a surface is carried out at high temperatures =1000 °С for 5 minutes. It is experimentally found that the microhardness of the surface layer increased by about 30% compared with the microhardness of the substrate, and that the thickness of the boride layer depends on the presence of liquid glass in the coating. It has been established that specially calculated proportions of ammonia, liquid glass, and charcoal contribute to the formation of an extensive diffusion zone of iron borides, the formation of which is due to the anomalously high diffusion mass transfer of boron into the matrix.

High Strength Sinter-Hardening Powder Metallurgy Alloys

2008 ◽  
Vol 51 ◽  
pp. 3-9 ◽  
Author(s):  
K.S. Hwang ◽  
M.W. Wu ◽  
Chia Cheng Tsai
Keyword(s):  
Tensile Strength ◽  
Powder Metallurgy ◽  
Cooling Rate ◽  
High Hardness ◽  
High Strength ◽  
Alloying Elements ◽  
Cooling Rates ◽  
The Matrix ◽  
Fast Cooling ◽  
The Cost

High strength and high hardness can be readily attained after sintering when sinter-hardening grade powder metallurgy alloys are used. However, fast cooling rates greater than 60°C/min are usually required. This increases the cost of the sintering equipment and maintenance. To lower the required minimum cooling rate, the homogeneity of the alloying elements in the matrix and the hardenability of the material must be improved. Among the various popular alloying elements, nickel and carbon are the two most non-uniformly distributed elements due to their repelling effect. It is found that to improve their homogenization, the addition of Cr and Mo can alleviate the repelling effect between Ni and C. As a result, weak Ni-rich/C-lean ferrite and austenite are eliminated and replaced by hard bainite and martensite. A tensile strength of 1323 MPa and a hardness of 39 HRC are attained in sinter-hardened Fe-3Cr-0.5Mo-4Ni-0.5C compacts without any quenching treatment.

scholarly journals Boron Diffusion During Carbon Steel Boriding

2021 ◽  
pp. 64-67
Author(s):  
E.P. Shevchuk ◽  
V.A. Plotnikov ◽  
G.S. Bektasova
Keyword(s):  
Carbon Steel ◽  
Thermal Treatment ◽  
Diffusion Zone ◽  
High Hardness ◽  
High Rate ◽  
Induction Treatment ◽  
Boron Diffusion ◽  
Zone Formation ◽  
Diffusion Layers ◽  
Diffusion Boriding

Protective boride coatings are obtained by chemical-thermal treatment of powder mixtures during induction furnace heating and micro-arc chemical-thermal treatment. Their usage can significantly increase the reliability and durability of steel products. The calculated composition of the saturating charge and the welding flux used to boride steel 20 samples demonstrates that obtained boride diffusion coatings are characterized by high hardness and an extensive diffusion zone. The most optimal composition of the charge that contains iron and boric acid is found to be in the proportion of Fe-25%+H3BO3-75 %. The analysis of the distribution of microhardness over the cross section of coated samples is carried out. The comparative data for the diffusion coefficients and the thickness of the diffusion layers obtained experimentally are presented. The application of the discussed methods makes it possible to intensify the process of diffusion boriding and to ensure the formation of an extensive diffusion zone on the surface of carbon steel products with a high rate of hardening zone formation. The duration of the process is 5 minutes for the induction treatment and 54.05 s for micro-arc chemical-thermal surfacing. It is the main advantage of the experimental techniques mentioned above.

Effects of the Microstructure and Mechanical Properties for Wear Resistant Casting Surface with Vacuum Evaporable Pattern Casting Infiltration Process

2011 ◽  
Vol 291-294 ◽  
pp. 176-179
Author(s):  
Da Chun Yang
Keyword(s):  
Matrix Material ◽  
Composite Layer ◽  
High Strength ◽  
Boron Steel ◽  
Casting Surface ◽  
Infiltration Process ◽  
Wear Resistant ◽  
New Process ◽  
The Matrix ◽  
High Boron

Wear-resistant casting was made by V-EPC infiltration process. The matrix material was high boron steel casting. Surface composite materials layer was ceramic particles, such as WC, Ferrochromium, and Borax, etc. High boron molten metal was infiltrated into the composite layer and a good cast-infiltration layer may be formed by the interaction of vacuum and high temperature. The wear-resistant casting made with this process has high strength, hardness, and good wear-resistance. It is a new process that wear-resistant casting will be made of.

AMPCO 483

Alloy Digest ◽  
1978 ◽  
Vol 27 (4) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Base Alloy ◽  
High Hardness ◽  
High Strength ◽  
Heat Treating ◽  
Good Resistance ◽  
Copper Base ◽  
Copper Base Alloy

Abstract AMPCO 483 is a copper-base alloy that can be used in the cast or wrought form. It provides high strength, high hardness, excellent resistance to corrosion and good resistance to fatigue and wear. It is well suited for service at temperatures up to 750 F and for applications such as pickling equipment, nuts and marine hardware. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: Cu-352. Producer or source: Ampco Metal Inc..

Research on High-Speed Cutting of Cr12MoV Hardened Steel - A Review

2020 ◽  
Vol 15 ◽  
Author(s):  
Fei Sun ◽  
Guohe Li ◽  
Qi Zhang ◽  
Meng Liu
Keyword(s):  
High Speed ◽  
Cutting Temperature ◽  
High Hardness ◽  
High Strength ◽  
Hardened Steel ◽  
Parameters Optimization ◽  
Future Research ◽  
High Speed Machining ◽  
Machined Surface ◽  
Stamping Die

: Cr12MoV hardened steel is widely used in the manufacturing of stamping die because of its high strength, high hardness, and good wear resistance. As a kind of mainstream cutting technology, high-speed machining has been applied in the machining of Cr12MoV hardened steel. Based on the review of a large number of literature, the development of high-speed machining of Cr12MoV hardened steel was summarized, including the research status of the saw-tooth chip, cutting force, cutting temperature, tool wear, machined surface quality, and parameters optimization. The problems that exist in the current research were discussed and the directions of future research were pointed out. It can promote the development of high-speed machining of Cr12MoV hardened steel.

scholarly journals Effect of weld metal composition on impact toughness properties of shielded metal arc welded ultra-high hard armor steel joints

2020 ◽  
Vol 29 (1) ◽  
pp. 186-194
Author(s):  
V. Balaguru ◽  
Visvalingam Balasubramanian ◽  
P. Sivakumar
Keyword(s):  
Impact Toughness ◽  
Weld Metal ◽  
Welded Joints ◽  
Weight Ratio ◽  
High Hardness ◽  
High Strength ◽  
Solidification Mode ◽  
Austenitic Phase ◽  
Ferrite Number ◽  
Steel Joints

AbstractNowadays, ultra-high hard armor (UHA) steels are employed in armor tracked vehicle (ATV) construction because of their high hardness, high strength to weight ratio, and excellent toughness. UHA steels are usually welded using austenitic stainless steel (ASS) welding consumables, to avoid hydrogen-induced cracking (HIC). The use of ASS consumables to weld the above steel was the only available remedy because of higher solubility of hydrogen in the austenitic phase. In this investigation, an attempt was made to investigate the effect of ASS consumables (with different Creq/Nieq ratio) on solidification mode, impact toughness and microstructural characteristics of shielded metal arc (SMA) welded UHA steel joints. The welded joints were characterised based on impact toughness properties, hardness, and microstructural features. As the ferrite number increases with an increase in Creq/Nieq ratio result in different solidification mode (A, FA, F). It is also found that ferrite number of weld metal has appreciable influence on impact toughness and has inversely proportional relationship with impact toughness of the welded joints.

scholarly journals Wear Resistance of TiC Reinforced Cast Steel Matrix Composite

2017 ◽  
Vol 17 (1) ◽  
pp. 143-146 ◽  
Author(s):  
S. Sobula ◽  
E. Olejnik ◽  
T. Tokarski
Keyword(s):  
Wear Resistance ◽  
Matrix Composite ◽  
Base Alloy ◽  
Cast Steel ◽  
Composite Layer ◽  
Wear Loss ◽  
Steel Matrix ◽  
Soft Matrix ◽  
Base Steel ◽  
The Matrix

Abstract Wear resistance of TiC-cast steel metal matrix composite has been investigated. Composites were obtained with SHSB method known as SHS synthesis during casting. It has been shown the differences in wear between composite and base cast steel. The Miller slurry machine test were used to determine wear loss of the specimens. The slurry was composed of SiC and water. The worn surface of specimens after test, were studied by SEM. Experimental observation has shown that surface of composite zone is not homogenous and consist the matrix lakes. Microscopic observations revealed the long grooves with SiC particles indented in the base alloy area, and spalling pits in the composite area. Due to the presence of TiC carbides on composite layer, specimens with TiC reinforced cast steel exhibited higher abrasion resistance. The wear of TiC reinforced cast steel mechanism was initially by wearing of soft matrix and in second stage by polishing and spalling of TiC. Summary weight loss after 16hr test was 0,14÷0,23 g for composite specimens and 0,90 g for base steel.

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