scholarly journals Impact of Magnetic-Pulse and Chemical-Thermal Treatment on Alloyed Steels’ Surface Layer

2022 ◽  
Vol 12 (1) ◽  
pp. 469
Author(s):  
Kateryna Kostyk ◽  
Ivan Kuric ◽  
Milan Saga ◽  
Viktoriia Kostyk ◽  
Vitalii Ivanov ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Hardened Layer ◽  
Bearing Steel ◽  
Boride Layer ◽  
Magnetic Pulse ◽  
Hard Alloys ◽  
Pulse Treatment ◽  
Alloy Steels

The relevant problem is searching for up-to-date methods to improve tools and machine parts’ performance due to the hardening of surface layers. This article shows that, after the magnetic-pulse treatment of bearing steel Cr15, its surface microhardness was increased by 40–50% compared to baseline. In this case, the depth of the hardened layer was 0.08–0.1 mm. The magnetic-pulse processing of hard alloys reduces the coefficient of microhardness variation from 0.13 to 0.06. A decrease in the coefficient of variation of wear resistance from 0.48 to 0.27 indicates the increased stability of physical and mechanical properties. The nitriding of alloy steels was accelerated 10-fold that of traditional gas upon receipt of the hardened layer depth of 0.3–0.5 mm. As a result, the surface hardness was increased to 12.7 GPa. Boriding in the nano-dispersed powder was accelerated 2–3-fold compared to existing technologies while ensuring surface hardness up to 21–23 GPa with a boride layer thickness of up to 0.073 mm. Experimental data showed that the cutting tool equipped with inserts from WC92Co8 and WC79TiC15 has a resistance relative to the untreated WC92Co8 higher by 183% and WC85TiC6Co9—than 200%. Depending on alloy steel, nitriding allowed us to raise wear resistance by 120–177%, boriding—by 180–340%, and magneto-pulse treatment—by more than 183–200%.

scholarly journals Strengthening the Surface Layer of Tools with State-of-the-Art Technologies

2021 ◽  
Vol 22 (1) ◽  
pp. 78-102
Author(s):  
K. O. Kostyk ◽  
V. O. Kostyk ◽  
V. D. Kovalev
Keyword(s):  
Wear Resistance ◽  
Surface Layer ◽  
Surface Hardening ◽  
High Speed ◽  
Cutting Tool ◽  
Surface Condition ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Boride Layer ◽  
Hard Alloys

Increasing both the service life and the wear resistance of the tool by surface hardening is an urgent issue. Its solution contributes to a significant increase in the performance of products. Available methods of surface hardening of tools, based on coating or changing the surface condition, are becoming increasingly important due to the complexity of the operation of products. Plates made of the T5K10 (85%WC–6%TiC–9%Co) and T15K6 (79%WC–15%TiC–6%Co) hard alloys as well as cylindrical samples made of the W6Mo5Cr4V2 and W18Cr4V high-speed steels are used for the study. Studies have shown that, after processing the T15K6 alloy plates with a pulsed magnetic field, the cutting tool life improved by more than 200% as compared to the untreated ones. The proposed method will increase the strength of carbide plates and stabilize the physical and mechanical properties of the cutting tool. For tools made of alloy steels, the hardening treatment is carried out by the boron method in pastes with nanodisperse powders. As shown, the thickness of the boride layer for high-speed steels increases with the duration of the process; however, its growth rate depends on the composition of the steel. An increase in the holding time of the chemical and thermal treatment leads to the growth of boride layers. The layer thickness changes quadratically (as a second-degree polynomial) with duration time. A feature of formation of diffusion layers is revealed. The dependences of both the surface hardness and the thickness of boride layer on the borating time for high-speed steels are also shown. Studies have shown that boriding in a nanodisperse medium can significantly increase the wear resistance of steels. The method of expert assessments of the maximum values of the surface properties of the studied steels is carried out. As shown, it is more rational to use W6Mo5Cr4V2 steel as a cutting tool after hardening the surface layer by boriding in a nanodisperse boron-containing powder. The proposed processing method demonstrates the prospects of using it to improve the performance of products. In addition, this method of hardening can significantly increase the wear resistance of materials (by ≈3.38–3.75 times) as compared to steels without processing.

Study of structure and properties of steel 38KhN3МFА after low-temperature liquid borating

2020 ◽  
pp. 309-313
Author(s):  
S.G. Tsikh ◽  
A.A. Krasulya ◽  
A.S. Pomel’nikova
Keyword(s):  
Low Temperature ◽  
Surface Hardness ◽  
Hardened Layer ◽  
Boride Layer ◽  
Boride Coating ◽  
Solid Core ◽  
Electron Microscopic ◽  
X Ray ◽  
Temperature Liquid ◽  
Boride Phases

The effect of low-temperature liquid borating on the structure and hardness of steel 38KhN3МFА is studied. It is found that in the borating process at temperature 600...660 °C and duration 8...32 hours boride coating with thickness of 6...19 μm with surface hardness of 1900...2000 HV is formed on the steel surface. The optimal borating regimes are determined, in which hardened layer with solid core is formed. The presence of two boride phases FeB and Fe2B in the boride layer is established by metallographic, X-ray and electron microscopic analyzes.

Structure, strength, and wear resistance of hadfield steel subjected to surface magnetic-pulse treatment

2009 ◽  
Vol 39 (8) ◽  
pp. 629-632
Author(s):  
V. L. Volodin ◽  
L. B. Zuev ◽  
T. V. Volodin ◽  
V. E. Gromov
Keyword(s):  
Wear Resistance ◽  
Hadfield Steel ◽  
Magnetic Pulse ◽  
Pulse Treatment ◽  
Structure Strength

Treatment of Surface Properties of Titanium with Plasma (Ion) Nitriding

2009 ◽  
Vol 283-286 ◽  
pp. 401-405 ◽  
Author(s):  
H. Yilmazer ◽  
S. Yilmaz ◽  
M.E. Acma
Keyword(s):  
Wear Resistance ◽  
Titanium Alloys ◽  
Surface Properties ◽  
Surface Hardness ◽  
Hardened Layer ◽  
Ion Nitriding ◽  
Nitriding Time ◽  
X Ray ◽  
Nitrided Surface ◽  
Nitrided Titanium

In order to improve the poor surface hardness and the wear resistance, titanium has been nitrided with plasma (ion) nitriding which is one of the methods to treat surface properties of titanium alloys. The increment at surface hardness and so the wear resistance of nitrided titanium alloys has been provided by means of compound layer (ε-Ti2N+δ-TiN) and diffusion zone (α-Ti) occurred by plasma ion nitriding. The goal of the present paper is to investigate effects of nitriding temperature and nitriding time on the microstructure and hardness value of nitrided surface layers. A systematic study was undertaken with specimens of commercial pure Ti and Ti-6Al-4V alloy. As treatment parameters, we have used; nitriding time (from 2 to 9 hour), nitriding atmosphere (H2-80%N2), total pressure (1 kPa) and cathode temperature (from 600 to 800 oC). The Vickers indenter was used for analysis of the micro hardness measurements. The thin hardened layer at the nitrided surface was characterized by glancing-angle X-ray difractometer. X-ray diffraction analysis has confirmed the formation of ε-Ti2N and δ-TiN phases on the nitrided specimens. Experimental details and characterization of plasma (ion) nitrided titanium have reported and discussed.

Modelling of operational, physical and mechanical properties of tool steels for cold deformation dies

2021 ◽  
pp. 70-72
Author(s):  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Impact Toughness ◽  
Cold Deformation ◽  
Correlation Coefficients ◽  
Physical And Mechanical Properties ◽  
Hardened Layer ◽  
Tool Steels ◽  
Correlation Graph ◽  
Carbide Inclusions

Correlations between the parameters of the structure of the hardened layer and the operational properties of cold deformation dies made of case-hardened steels are considered. Correlation coefficients are calculated and a correlation graph is built. A stable (95 %) correlation is shown between wear resistance, the amount and size of carbide inclusions, the effective thickness and hardness of the case-hardened layer. Keywords: correlation graph, carbonization, diffusion layer, carbides, wear resistance, hardness, strength, impact toughness. [email protected]

Study of plasma-hardened wheel steel using nanoindentation

2020 ◽  
Vol 86 (4) ◽  
pp. 56-60
Author(s):  
A. T. Kanaev ◽  
Z. M. Ramazanova ◽  
S. K. Biizhanov
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Surface Layer ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Elastic Recovery ◽  
Physical And Mechanical Properties ◽  
Hardened Layer ◽  
Wheel Steel ◽  
Plasma Hardening

The necessity and possibility of using nanoindentation in studying the physical and mechanical properties of plasma-hardened wheel steel are considered. The goal of the study is demonstration and substantiation of significant differences in the mechanical properties and behavior of the materials in nanoscale tests from those determined in traditional macroscopic tests. The method was implemented using a NanoHardnessTecter nanohardness tester. The electric field formed in the nanoscale hardness tester pressed on the indenter and the diamond tip of the indenter is immersed in the surface layer of the material under study. The characteristics of the surface layer are determined using the developed software. Knowledge of the physicomechanical characteristics of the material (hardness, Young’s modulus, elastic recovery, etc.) which affect the wear resistance of the surface layers, allows one to evaluate and select the optimal surface modification technology using plasma hardening. The credibility of determination depends on the parameters of measuring equipment and compliance with the requirements to the depth of the imprint depending on the thickness of the hardened layer. The studies were carried out on the samples cut from the rim and crest of a railway wheel subjected to surface plasma hardening on a UPNN-170 installation (Russia). It is shown that the hardness (according to Vickers HV and H) of the rim is greater, and Young’s modulus, on the contrary, is less than the corresponding characteristics of the crest. Moreover, the wear resistance of hardened structural steel increases after nanostructural friction treatment.

Effect of Nanostructurisation of Structural Steels on its Wear Resistance and Hydrogen Embittlement Resistance

2014 ◽  
Vol 225 ◽  
pp. 65-70 ◽  
Author(s):  
Hryhoriy Nykyforchyn ◽  
Volodymyr Kyryliv ◽  
Olga Maksymiv
Keyword(s):  
Wear Resistance ◽  
High Speed ◽  
Surface Hardness ◽  
Structural Steels ◽  
Matrix Structure ◽  
Pulse Treatment ◽  
Tempering Temperature ◽  
Medium Carbon ◽  
Mechanical Pulse Treatment ◽  
Mechanical Pulse

Surface mechanical pulse treatment of medium-carbon low alloyed steels by high speed friction has been developed. Its major features are surfaces provided with the nanostructure with grain size of 20...50 nm, increased surface hardness and, correspondingly wear resistance. This nanostructure is subjected to the tempering temperature of 500 °С. Hydrogen charging of the strengthening materials decreases their plasticity, more considerably in steels with higher carbon content. However, it is possible to use mechanical pulse treatment to achieve high characteristics of strength, wear resistance and plasticity in hydrogen, selecting as-received matrix structure and the tempering temperature after surface treatment.

Materials for bullet core

2020 ◽  
Vol 2020 (10) ◽  
pp. 8-21
Author(s):  
A. G. Kolmakov ◽  
◽  
I. O. Bannykh ◽  
V. I. Antipov ◽  
L. V. Vinogradov ◽  
...  
Keyword(s):  
High Speed ◽  
Bending Strength ◽  
Low Alloy Steels ◽  
Hard Alloys ◽  
Small Arms ◽  
Alloy Steels ◽  
Materials Used ◽  
Basic Ideas ◽  
New Generation ◽  
Natural Composite

he basic ideas about the process of introducing cores into protective barriers and the most common core patterns and their location in conventional and sub-caliber small arms bullets are discussed. The materials used for manufacture of cores are analyzed. It is concluded that for mass bullets of increased armor penetration the most rational choice can be considered the use of high-carbon low-alloy steels of a new generation with a natural composite structure and hardness of up to 70 HRC. For specialized armor-piercing bullets, cores made from promising economically-alloyed high-speed steels characterized by a high complex of «hardness—bending strength» are better alternative than ones made of hard alloys or tungsten alloys.

DILLIDUR 450V

Alloy Digest ◽  
2011 ◽  
Vol 60 (12) ◽  
Keyword(s):  
Fracture Toughness ◽  
Wear Resistance ◽  
Physical Properties ◽  
Tensile Properties ◽  
Room Temperature ◽  
Surface Hardness ◽  
Heat Treating ◽  
Hot Working ◽  
Resistant Steel ◽  
Bend Strength

Abstract Dillidur 450V is a water hardened wear-resistant steel with surface hardness at room temperature of 420-480 HB. The steel is easy to weld and bend. Hot working is not recommended. This datasheet provides information on composition, physical properties, hardness, tensile properties, and bend strength as well as fracture toughness. It also includes information on wear resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-638. Producer or source: Dillinger Hütte GTS.

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