scholarly journals The effect of the preheating on to properties of the wear resistant welds

2020 ◽  
Vol 92 (2) ◽  
pp. 7-14 ◽  
Author(s):  
Marek Gucwa ◽  
Jerzy Winczek ◽  
Miloš Mičian
Keyword(s):  
Surface Layer ◽  
Main Parameter ◽  
Heating Temperature ◽  
High Hardness ◽  
Operating Conditions ◽  
Wear Resistant ◽  
Optimum Heating

Wear resistant welds are used in many industries when it is necessary to protect machine components and structures against wear caused by operating conditions. Often the main parameter determining the usefulness of these welds is high hardness reaching about 60HRC. In many cases, after the surfacing process, a mesh of cracks is formed in the surface layer, which can affect the durability of the hard-wearing layers used. The paper presents the analysis of the influence of preheating before welding up to 400 ° C on the properties of welds and its effect on the number of cracks in the surface layer. The use of preheating allowed to reduce the number of cracks in the surfacing to 1. The optimum heating temperature was 200 ° C, for which the number of cracks was reduced and the lowest wear was recorded.

scholarly journals Development of technology for manufacture of bimetal camps of ship diesels

2018 ◽  
pp. 163-169
Author(s):  
O. Stalnichenko ◽  
B. Smazhylo ◽  
R. Kotenko
Keyword(s):  
Surface Layer ◽  
Mechanical Treatment ◽  
Low Cost ◽  
High Hardness ◽  
Wear Resistant ◽  
Wear Resistant Coatings

The results of the development of the technology for the manufacture of bimetallic fuselage washers of marine ICE, which assumes the basis of the washer to be made from low-cost steels with the application of a high-hardness surface layer on the cams instead of cementation. To implement the idea, a number of mechanisms and devices have been developed and manufactured that have enabled the application of wear-resistant coatings and mechanical treatment of paddles.

Structure of the surface layer of a wear-resistant coating after treatment with a high-intensity electron beam

2015 ◽  
Vol 9 (5) ◽  
pp. 934-938 ◽  
Author(s):  
S. V. Raykov ◽  
E. V. Kapralov ◽  
E. S. Vashchuk ◽  
E. A. Budovskikh ◽  
V. E. Gromov ◽  
...  
Keyword(s):  
Surface Layer ◽  
Electron Beam ◽  
High Intensity ◽  
Wear Resistant Coating ◽  
Wear Resistant ◽  
Resistant Coating

Increasing Hardness of Surface Layer of Low-Carbon Steel by Account of Plasma Treatment of Coating Modification

2021 ◽  
Vol 316 ◽  
pp. 794-802
Author(s):  
Andrey E. Balanovsky ◽  
Van Trieu Nguyen
Keyword(s):  
Surface Layer ◽  
Thermal Treatment ◽  
Plasma Treatment ◽  
Plasma Heating ◽  
High Surface ◽  
Surface Hardness ◽  
High Hardness ◽  
Diffusion Region ◽  
Low Carbon ◽  
Wide Range

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.

scholarly journals Carbonitration of a Tool for Pressing Stainless Steel Pipes

2020 ◽  
Vol 7 (2) ◽  
pp. C17-C21
Author(s):  
I. V. Ivanov ◽  
M. V. Mohylenets ◽  
K. A. Dumenko ◽  
L. Kryvchyk ◽  
T. S. Khokhlova ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Treatment ◽  
Heat Resistance ◽  
Alkali Metals ◽  
Matrix Ring ◽  
High Hardness ◽  
Operating Conditions ◽  
Matrix Rings ◽  
Conventional Heat Treatment ◽  
The Stability

To upgrade the operational stability of the tool at LLC “Karbaz”, Sumy, Ukraine, carbonation of tools and samples for research in melts of salts of cyanates and carbonates of alkali metals at 570–580 °C was carried out to obtain a layer thickness of 0.15–0.25 mm and a hardness of 1000–1150 НV. Tests of the tool in real operating conditions were carried out at the press station at LLC “VO Oscar”, Dnipro, Ukraine. The purpose of the test is to evaluate the feasibility of carbonitriding of thermo-strengthened matrix rings and needle-mandrels to improve their stability, hardness, heat resistance, and endurance. If the stability of matrix rings after conventional heat setting varies around 4–6 presses, the rings additionally subjected to chemical-thermal treatment (carbonitration) demonstrated the stability of 7–9 presses due to higher hardness, heat resistance, the formation of a special structure on the surface due to carbonitration in salt melts cyanates and carbonates. Nitrogen and carbon present in the carbonitrided layer slowed down the processes of transformation of solid solutions and coagulation of carbonitride phases. The high hardness of the carbonitrified layer is maintained up to temperatures above 650 °C. If the stability of the needle-mandrels after conventional heat treatment varies between 50–80 presses, the needles, additionally subjected to chemical-thermal treatment (carbonitration) showed the stability of 100–130 presses due to higher hardness, wear resistance, heat resistance, the formation of a special surface structure due to carbonitration in melts of salts of cyanates and carbonates. Keywords: needle-mandrel, matrix ring, pressing, heat treatment, carbonitration.

scholarly journals The laboratory tests of hybrid layers combining hardfacing and nitriding dedicated to increase the durability of forging tools in hot forging processes

2019 ◽  
Vol 91 (2) ◽  
Author(s):  
Paweł Widomski ◽  
Zbigniew Gronostajski ◽  
Marcin Kaszuba ◽  
Jagoda Kowalska ◽  
Mariusz Pawełczyk
Keyword(s):  
Surface Layer ◽  
Chemical Composition ◽  
Laboratory Tests ◽  
Hot Forging ◽  
Composition Analysis ◽  
Wear Resistant ◽  
Gas Nitriding ◽  
Use Wear ◽  
Different Types ◽  
Hybrid Layers

In response to the growing need to use wear-resistant layers that increase durability of tools in forging pro-cesses, hybrid layers have been proposed that combine hardfacing with nitriding treatment. This article presents the results of laboratory tests of surface wear-resistant layers made with a new hybrid technology Gas-Shielded Metal Arc surfacing (hardfacing) with ZeroFlow gas nitriding. Specimens made with hardfacing or nitriding were prepared and examined. Analysis covered the thorough microstructure study, EDX chemical composition analysis and microhardness analysis. In experiment, 3 different types of nitrided layers were proposed for alpha, gamma prim and epsilon nitrides in the surface layer. The results of metallographic research in the surface layer was presented. The analysis of chemical composition in the particular overlay welds was performed to determine the content of alloying elements in the particular overlay welds. The susceptibility to nitriding of used weld materials as well as the ability to form particular types of nitrides on selected welded substrates was also tested.

Study of corrosion resistance of doped surface layer with CuSn—CrxCy composition after plasma hardening

2021 ◽  
pp. 215-220
Author(s):  
Nguyen Van Trieu ◽  
N.A. Astafeva ◽  
A.E. Balanovsky ◽  
A.N. Baranov
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Chromium Content ◽  
High Hardness ◽  
Plasma Coating ◽  
Corrosion Current ◽  
Ph Values ◽  
Alloyed Surface ◽  
Welding Electrode ◽  
Acidity Parameter

In the process of plasma surface hardening, coatings based on a mixture of CuSn alloy and 10/20 % OK 84.78 additive with high hardness were obtained. The study of the microstructures of the coatings showed that the content of the austenite phase decreases with an increase in the content of chromium carbide in the composition. The influence of the acidity parameter on the corrosion resistance of the alloyed surface layer with the composition of the mixture of alloys CuSn and the coating of the welding electrode OK 84.78 was evaluated. Corrosion control in 3% NaCl solutions with different pH values showed that the plasma coating has high corrosion resistance at pH = 7 and decreases by 2 times at pH = 3. An increase in the chromium content leads to an increase in the corrosion potential, and the presence of cracks leads to an increase in the corrosion current density.

Investigation of the modification effect on performance properties of cast iron molds

2021 ◽  
pp. 23-28
Author(s):  
V. A. Gulevskiy ◽  
◽  
S. N. Tsurikhin ◽  
V. V. Gulevskiy ◽  
N. Yu. Miroshkin ◽  
...  
Keyword(s):  
Cast Iron ◽  
Outer Surface ◽  
Heating Temperature ◽  
Primary Aluminum ◽  
Operating Conditions ◽  
Senior Lecturer ◽  
Advantages And Disadvantages ◽  
Stress And Deformation ◽  
Consumable Electrodes

Research is devoted to the influence of the technological method of modifying gray cast iron for the manufacture of steel casting molds. Heavy operation imposes stringent requirements both on the design of molds and on the materials from which they are made. They reliably withstand the effects of steel poured into them, having a temperature of 1600–1700 °C, thermal shock, which is directly proportional to this temperature, as well as significant effects of cyclic thermal stress and deformation. Specific operating conditions of molds (high heating temperature, their installation on movable and stationary ditches, intensive traffic flows, etc.) complicate the necessary processes directly during their operation. Modeling geometric shapes on a scale of geometric similarity 1:10. Tests were carried out on molds cast from cast iron for consumable electrodes, modified with ferrosilicon (FS65 GOST 1415-93), primary aluminum A99 (GOST 11069-2001), vanadium slag (SHVD-1 TU14-11-178-86), FSB-30) and silicomishmetal (SIMISH-1). These modifiers were chosen for modification, as they are widely used in production. Thus, the conducted studies of the nature of the deformation of the walls of the molds and the stress-strain state on models made of gray and modified cast iron make it possible to assess the advantages and disadvantages of the resulting structure and shape of graphite. Further, the methods of the rational formula of the outer surface of profiled and sheet molds are used, having predetermined the nature of destruction in advance. The use of thin-walled used rational forms can significantly reduce their specific consumption. The study of the quality of the metal cast into the experimental curved outer surface showed that the macrostructure of the metal of the experimental and ordinary ingots is the same. The work was attended by N.V Markina, senior lecturer at the Dept. of Machines and Foundry Technology, Volgograd State Technical University.

A Study on the Arc Spraying of 7Cr13 Cored Wire and Tribological Properties of the Composite Coating

1998 ◽  
Author(s):  
B. Xu ◽  
S. Ma ◽  
J. Wang ◽  
J. Tan
Keyword(s):  
Bond Strength ◽  
Composite Coating ◽  
Tribological Properties ◽  
High Hardness ◽  
Wear Resistant Coating ◽  
Arc Spraying ◽  
Metallurgical Process ◽  
Cored Wire ◽  
Wear Resistant ◽  
Wire Arc Spraying

Abstract For the purpose of getting high hardness and high wear-resistant coating by arc spraying technology, the arc spraying of 7Cr13 cored wire is adopted in this paper. The metallurgical process of the cored wire arc spraying is discussed. The bond strength, hardness and tribological properties of the composite coating are investigated.

Finite Element Analysis of Tool Wear in Hot Machining Process

2019 ◽  
pp. 232-248
Author(s):  
Asit Kumar Parida
Keyword(s):  
Tool Wear ◽  
Room Temperature ◽  
Heating Temperature ◽  
Chip Morphology ◽  
High Hardness ◽  
Tool Temperature ◽  
Element Analysis ◽  
Hot Machining ◽  
Wear And Corrosion Resistance ◽  
Wear Tool

Super alloys have been used widely in all sectors (e.g., automobile, aerospace, biomedical, etc.) for their properties like high hardness, high wear, and corrosion resistance. A central challenge is the significantly higher temperature and pressure on the cutting tool, hence rapid tool wear and bad surface finish. In the present study, a FEM analysis has been developed to calculate the effect of preheating temperature on the surface of the workpiece on tool wear on machining Inconel 718. Usui's tool wear model has been implemented in DEFORM software. In order to validate the results, an experimental investigation has been carried out with same cutting conditions. The evaluated results were also compared with the room temperature machining condition. It was observed that the heating temperature increased the tool life by reducing tool wear, tool temperature compared to room temperature machining condition. The predicted tool wear, tool temperature, and chip morphology have been compared with the experimental results and good correlation was found.

Modeling Technological Parameters for Producing Combined Electrospark Deposition Coatings

2019 ◽  
Vol 968 ◽  
pp. 131-142 ◽  
Author(s):  
Viacheslav Tarelnyk ◽  
Ievgen Konoplianchenko ◽  
Nataliia Tarelnyk ◽  
Aleksey Kozachenko
Keyword(s):  
Electrode Materials ◽  
Protective Coatings ◽  
High Hardness ◽  
Mass Transfer Process ◽  
Electrode Pair ◽  
Surface Plastic ◽  
Technological Parameters ◽  
Electrospark Deposition ◽  
Wear Resistant

The paper represents a formalized methodology for solving the problem of creating fundamentally new materials, such as "base - coating" ones, which have increased surface wear resistance and relatively high strength and viscosity. Electrospark alloying (ESA) method is proposed as a process for depositing protective coatings on metal surfaces. There are considered the issues of improving the quality of the coatings formed by the ESA method. There is specified a feature of processing the surfaces having been treated with the use of the ESA method, which feature being associated with a relatively small thickness of the layers formed (tens of micrometers). Since to reduce the roughness of the surface, the process of grinding is difficult or even unacceptable to perform, it has been suggested to use the method of surface plastic deformation (SPD). One of the effective SPD methods for finishing the parts is a diamond smoothing process, which, in contrast to running-in with a ball or roller, allows processing the parts of very high hardness values. As a reserve to improve the quality of coatings formed by the ESA method, there is considered a process for producing combined electrospark deposition coatings (CEC) with hard wear-resistant and soft anti-friction metals integrated therein. There are represented the results of mass transfer process investigation performed at forming the CEC on the specimens of steel 45 with indium, tin and copper being used as soft antifriction metals, and tungsten and hard alloy of VK8 grade applied as wear-resistant materials. There is represented a mathematical model for calculating the main ESA technological parameters being necessary for forming the CEC and allowing to predict the weight gain (increase in weight) and size gain (increase in size) at the cathode (the part). It allows predicting the CEC main technological parameters for any electrode pair materials (substrate material and electrode materials making up the CEC).

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