scholarly journals The Evaluation of the Effectiveness of Reinforcement by Cemented-Carbide Plates in Two Design Variants of the Chisels Intended for Cultivation–Sowing Aggregates

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1020
Author(s):  
Piotr Kostencki ◽  
Tomasz Stawicki ◽  
Aleksandra Królicka
Keyword(s):  
Martensitic Steel ◽  
Base Material ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Rake Face ◽  
The Matrix ◽  
Matrix Removal ◽  
Effective Reinforcement ◽  
Material Wear ◽  
Length Reduction

Field tribological tests of two design variants of chisels used in the teeth of a cultivation-sowing unit were carried out in this research. A characteristic feature of the first variant of chisels was the reinforcement of their contact surface and almost the entire rake surface by plates made of cemented carbides. On the other hand, the second variant of chisels was reinforced only in the area of the blade by two plates made of cemented carbides, soldered on the rake face of the elements. The use of the first variant of chisels contributed to a significant reduction in the wear rate of elements, especially in terms of thickness and width loss. Effective reinforcement of the rake face, with relatively lower resistance to length reduction in the elements, raises doubts as to the validity of the use of cemented-carbide plates on almost the entire length of their rake face, because the applied variant of chisels contributed to a significantly higher price. However, the second variant of chisels effectively limited the intensity of the loss of the length of the elements, and the cause of the loss of their usefulness as part of the base material wear. It was found that the main wear mechanism of the cemented-carbide plates consisted of matrix removal under the influence of the finest fraction of the soil, which weakened the embedding of carbides, and then crushing or chipping of carbide grains from the matrix, whereas the dominant wear mechanisms of martensitic steel were grooving and micro-cutting.

Effect of WC Contents on Microstructure and Properties of Steel-Bonded Cemented Carbide

2012 ◽  
Vol 184-185 ◽  
pp. 850-853
Author(s):  
Jun Ming Luo ◽  
Ji Lin Xu ◽  
Zheng Wei
Keyword(s):  
Mechanical Properties ◽  
Bending Strength ◽  
Microwave Sintering ◽  
Liquid Phase Sintering ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Sintering Process ◽  
Iron Powders ◽  
Microstructure And Properties ◽  
The Matrix

WC steel-bonded cemented carbides were prepared by microwave sintering through ball milling, press forming and sintering with iron powders as the matrix, WC particles as the reinforcements. The effect of WC contents on microstructure and properties of steel-bonded cemented carbide was studied. The results show that the steel-bonded cemented carbide sintered at 1280 °C is considered as a liquid phase sintering and Fe7W6, Fe2W2C and Fe6W6C new phases are generated during the sintering process. The relative density, microhardness and bending strength of the steel-bonded cemented carbide increase with increasing the WC contents. Moreover, the mechanical properties of steel-bonded cemented carbide are obviously improved after heat treatment.

scholarly journals Analysis of Different Complex Multilayer PACVD Coatings on Nanostructured WC-Co Cemented Carbide

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 823
Author(s):  
Danko Ćorić ◽  
Mateja Šnajdar Musa ◽  
Matija Sakoman ◽  
Željko Alar
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Base Material ◽  
Single Layer ◽  
Production Costs ◽  
Structural Defects ◽  
Cemented Carbides ◽  
Material System ◽  
Tin Coating ◽  
Ticn Coating

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion.

scholarly journals Welding thermal cycle-triggered precipitation processes in steel S700MC subjected to the thermo-mechanical control processing

2017 ◽  
Vol 62 (1) ◽  
pp. 321-326 ◽  
Author(s):  
J. Górka
Keyword(s):  
Thermomechanical Processing ◽  
Control Process ◽  
Base Material ◽  
Structural Defects ◽  
Accelerated Cooling ◽  
Internal Stresses ◽  
Mechanical Control ◽  
Thin Foils ◽  
Precipitation Processes ◽  
The Matrix

Abstract This study presents tests concerned with welding thermal process-induced precipitation processes taking place in 10 mm thick steel S700MC subjected to the Thermo-Mechanical Control Process (TMCP) with accelerated cooling. The thermomechanical processing of steel S700MC leads to its refinement, structural defects and solutioning with hardening constituents. Tests of thin foils performed using a transmission electron microscope revealed that the hardening of steel S700MC was primarily caused by dispersive (Ti,Nb)(C,N) precipitates (being between several and less than twenty nanometers in size). In arc welding, depending on a welding method and linear energy, an increase in the base material in the weld is accompanied by the increased concentration of hardening microagents in the weld. The longer the time when the base material remains in the liquid state, the greater the amount of microagents dissolved in the matrix. During cooling, such microagents can precipitate again or remain in the solution. An increase in welding linear energy is accompanied by an increase in the content of hardening phases dissolved in the matrix and, during cooling, by their another uncontrolled precipitation in the form of numerous fine-dispersive (Ti,Nb)(C,N) precipitates of several nm in size, leading to a dislocation density increase triggered by type 2 internal stresses.

scholarly journals Microstructure and Mechanical Properties of Modern 11%Cr Heat-Resistant Steel Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3430
Author(s):  
Grzegorz Golański ◽  
Jacek Słania ◽  
Marek Sroka ◽  
Paweł Wieczorek ◽  
Michał Urzynicok ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Welded Joints ◽  
Martensitic Steel ◽  
Base Material ◽  
Hardness Measurement ◽  
Power Industry ◽  
Strength Properties ◽  
Typical Structure ◽  
Δ Ferrite ◽  
The Impact

In addition to good high-temperature creep resistance and adequate heat resistance, steels for the power industry must have, among other things, good weldability. Weldability of such steels is one of the criteria determining whether or not the material is suitable for applications in the power industry. Therefore, when materials such as martensitic steel Thor 115 (T115) are introduced into the modern power industry, the quality and properties of welded joints must be assessed. The paper presents the results of metallographic and mechanical investigations of T115 martensitic steel welded joints. The analysis was carried out on joints welded with two filler metals: WCrMo91 (No. 1) and EPRI P87 (No. 2). The scope of the investigations included: microstructural investigations carried out using optical, scanning and transmission electron microscopy and mechanical testing, i.e., Vickers microhardness and hardness measurement, static tensile test and impact test. The macro- and microstructural investigations revealed correct structure of the weld, without welding imperfections. The microstructural investigations of joint No. 1 revealed a typical structure of this type of joint, i.e., the martensitic structure with numerous precipitates, while in joint No. 2, the so-called Nernst’s layers and δ-ferrite patches were observed in the weld fusion zone as well as the heat affected zone (HAZ). The mechanical properties of the test joints met the requirements for the base material. A slight influence of the δ-ferrite patch on the strength properties of joint No. 2 was observed, and its negative effect on the impact energy of HAZ was visible.

Development of the Synthetic Rock Technique for the Immobilization of Iodine: Kinetics of the Alumina Matrix Dissolution under High Alkaline Conditions

2012 ◽  
Vol 1518 ◽  
pp. 79-84 ◽  
Author(s):  
Hideaki Miyakawa ◽  
Tomofumi Sakuragi ◽  
Hitoshi Owada ◽  
Osamu Kato ◽  
Kaoru Masuda
Keyword(s):  
Dissolution Rate ◽  
Rate Constant ◽  
Base Material ◽  
Dissolution Behavior ◽  
Treatment Technique ◽  
Release Behavior ◽  
Alumina Matrix ◽  
Synthetic Rock ◽  
The Matrix ◽  
Iodine Release

ABSTRACTIodine filters expended after nuclear fuel reprocessing contain radioactive iodine (I-129), almost all of which exists as silver iodide (AgI). The synthetic rock technique is a solidification treatment technique using hot isostatic press (HIP), in which the alumina adsorbent base material is synthesized to form a dense solidified material (synthetic rock), and I-129 is physically confined in the form of AgI in the alumina matrix. Thus, it is necessary to understand the matrix dissolution behavior to evaluate the iodine release behavior.Experiments involving the dissolution of the matrix were carried out under various temperatures (35–70 °C) and pH values (10–12.5) that reflect the disposal conditions. The results of the experiments showed that the dissolution rate of Al visibly increases with temperature and pH. The dissolution rate constant was calculated from the initial data assuming the dissolution of the matrix as a primary reaction. The logarithmic rate constant showed a good linear correlation with the pH and the reciprocal of temperature. The 27Al-NMR analysis of the solutions of the dissolved matrix showed that the major chemical species present in the solutions was Al(OH)4-. This indicated that the dissolution of the matrix can be described by the following equation: Al2O3 + 2OH- + 3H2O → 2Al(OH)4-. Subsequently, the empirical equation of the rate of dissolution of the matrix as a function of the temperature and pH was derived. It will be used to evaluate the iodine release behavior from the synthetic rock.

In Situ Produced MMC Layer by Laser Melt Injection

2010 ◽  
Vol 649 ◽  
pp. 61-66
Author(s):  
Zoltán Kálazi ◽  
Viktória Janó ◽  
Gábor Buza
Keyword(s):  
Carbon Content ◽  
Composite Layer ◽  
Pure Titanium ◽  
Base Material ◽  
Titanium Content ◽  
Steel Sample ◽  
Low Carbon ◽  
The Matrix ◽  
Ti Powder

Tungsten (W) based alloy composite layer reinforced with TiC particles has been successfully prepared on unalloyed steel sample by LMI technology. In order to obtain in situ produced TiC reinforcement, pure titanium has been introduced to the melt pool. WC powder was added for increasing the carbon content of the layer in order to avoid the softening of the matrix (with low carbon content) during TiC formation. The present study aims to investigate the optimum amount of injected WC and Ti powder to improve wear resistance and hardness of the layer. Samples were investigated using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The maximum hardness of the layer has been reached ~900HV in case of 2-4wt% of titanium content. Ti has been collected all of the carbon from the matrix when titanium content was 9,6wt%, which resulted that the austenite and (Fe,W)6C phases have been disappeared. Only α-Fe and TiC phases were presented in the layer. The hardness of the layer reduced to the hardness of the base material.

scholarly journals Effect of Heat Treatment on the Microstructure and Properties of Ultrafine WC–Co Cemented Carbide

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1302
Author(s):  
Zhongnan Xiang ◽  
Zhanjiang Li ◽  
Fa Chang ◽  
Pinqiang Dai
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Service Life ◽  
Treatment Process ◽  
Cutting Conditions ◽  
Cemented Carbide ◽  
Cemented Carbides ◽  
Heat Treatment Process ◽  
Microstructure And Properties ◽  
Ultrafine Grained

In this paper, the effect of heat treatment on the microstructure and properties of a 0.8 μm WC–10%Co ultrafine cemented carbide was studied. The results show that the microstructural differences in ultrafine WC–Co cemented carbides without and with heat treatment are mainly reflected in the Co phase. For conventional cemented carbides, the hardness and wear resistance can be increased only at the expense of the toughness and strength. An ultrafine-grained WC–Co cemented carbide with good hardness and toughness can be obtained by strengthening the Co phase through an appropriate heat treatment process, and the service life of the ultrafine-grained WC–Co cemented carbide can be improved under actual cutting conditions.

scholarly journals Plasma-Assisted Chemical Vapor Deposition of TiBN Coatings on Nanostructured Cemented WC-Co

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1680
Author(s):  
Matija Sakoman ◽  
Danko Ćorić ◽  
Mateja Šnajdar Musa
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Hot Isostatic Pressing ◽  
Base Material ◽  
Surface Preparation ◽  
Chemical Vapor ◽  
Hard Coatings ◽  
Cemented Carbides ◽  
Wear Properties ◽  
Coating Adhesion

The plasma-assisted chemical vapor deposition (PACVD) technique has shown many advantages in applications, where thin coatings with superior wear properties are demanded, especially for geometrically complex parts. In this study, multilayered gradient TiBN coatings that were deposited on nanostructured cemented carbides by the PACVD method were investigated. Nanostructured samples of cemented carbides with the addition of 5 and 15 wt.% Co were sintered by the hot isostatic pressing, sinter-HIP technique. Surface preparation was conducted on samples in order to enable maximum coating adhesion. Tests that were conducted on produced samples aimed to investigate the mechanical and physical properties of coated samples. These tests included nanoindentation, surface layer characterization, and coating adhesion evaluation while using the Rockwell and scratch test. The obtained results confirmed that the PACVD process can be utilized for applying thin hard coatings to nanostructured cemented carbides that are produced by the sinter HIP process, resulting in a base material/ coating system that exhibits excellent physical and mechanical properties. The results presented in this paper give a valuable contribution to the research of TiBN coating systems and their potential for application under heavy wear conditions.

scholarly journals Application of hard surfacing for repairing of agricultural parts

2013 ◽  
Vol 59 (No. 2) ◽  
pp. 61-67 ◽  
Author(s):  
J. Viňáš ◽  
J. Brezinová ◽  
A. Guzanová ◽  
M. Kotus
Keyword(s):  
Arc Welding ◽  
Base Material ◽  
Wear Test ◽  
Crushed Rock ◽  
Metallographic Analysis ◽  
Shielded Metal Arc Welding ◽  
Metal Arc Welding ◽  
Covered Electrodes ◽  
Material Wear

The contribution deals with the analysis of claddings quality realised by shielded metal arc welding with covered electrodes. For cladding, covered basic electrodes marked as E Z Fe 8 EN 14700 and E Z Fe 15 EN 14700 were used. The third type of electrode was experimentally made basic electrode with operating name EW11 (wolfram content 11%). New share made of C50R EN10083/1-98 was used as reference material. Quality of repairing deposits was evaluated by micro hardness measuring and by metallographic analysis of claddings and base material. Wear resistance of claddings was determined by weight loss during abrasive wear test by wading in following loose abrasive agents &ndash; Al<sub>2</sub>O<sub>3</sub> (corundum), crushed rock and arable soil. &nbsp;

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