Case Study of the Effect of Precoating on the Decarburization of the Surface Layer of Forged Parts during the Hot Die Forging Process

This paper aims to evaluate the effect of pre-coating of forged parts on decarburization in the die forging process. The studies consisted of three stages. In the first instance, different coatings were tested under laboratory conditions by heating steel samples to the temperature of 1200 °C for over five minutes to model the preheating conditions of the induction. Next, testing continued in a commercial forging stand where we tested the effects of different coatings on the rods decarburization during the induction heating process, usually performed before forging. Once completed testing, the measurements and observations of the decarbonized layer were made. The third stage involved analysis of the decarburization of the forged parts after forging. The forged parts were made using precoating of pre-forging elements; pieces cut off a metal rod. Based on tests results, the possibility of using this solution in the technique of industrial hot forging was evaluated. The results of laboratory tests have confirmed that lubrication of metal pieces is sufficient, as well as proved it to be effective in reducing decarburization of the surface layer. Research works conducted in an induction heater showed differences in decarburization depending on a substance and concentration of lubricants that were used. These differences become more apparent when observing the surface layer of the forged parts. Results indicate that decarburization may be reduced to a minimum when we use Bonderite product in a concentration of 66% and 50%. Another lubricant, Berulit 913, may also be used. However, due to burning graphite in high temperatures, reduction of decarburization goes only as far as half of the thickness of the decarbonized layer. Condursal has no significant effect; nevertheless, it protects over the induction heating stage.

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Advanced Complex Analysis of the Thermal Softening of Nitrided Layers in Tools during Hot Die Forging

Materials ◽

10.3390/ma14020355 ◽

2021 ◽

Vol 14 (2) ◽

pp. 355

Author(s):

Jakub Krawczyk ◽

Paweł Widomski ◽

Marcin Kaszuba

Keyword(s):

Numerical Modeling ◽

Surface Layer ◽

Laboratory Tests ◽

Complex Analysis ◽

Nitrided Layer ◽

Hot Forging ◽

Thermal Softening ◽

Effect Of Temperature ◽

Destructive Effect ◽

Forging Process

This article is devoted to the issues of thermal softening of materials in the surface layer of forging tools. The research covers numerical modeling of the forging process, laboratory tests of tempering of nitrided layers, and the analysis of tempering of the surface layer of tools in the actual forging process. Numerical modeling was supported by measuring the temperature inside the tools with a thermocouple inserted into the tool to measure the temperature as close to the surface as possible. The modeling results confirmed the possibility of tempering the die material. The results of laboratory tests made it possible to determine the influence of temperature on tempering at different surface layer depths. Numerical analysis and measurement of surface layer microhardness of tools revealed the destructive effect of temperature during forging on the tempering of the nitrided layer and on the material layers located deeper below the nitrided layer. The results have shown that in the hot forging processes carried out in accordance with the adopted technology, the surface layer of working tools is overheated locally to a temperature above 600 °C and tempering occurs. Moreover, overheating effects are visible, because the surface layer is tempered to a depth of 0.3 mm. Finally, such tempering processes lead to a decrease in the die hardness, which causes accelerated wear because of the abrasion and plastic deformation. The nitriding does not protect against the tempering phenomenon, but only delays the material softening process, because tempering occurs in the nitrided layer and in the layers deeper under the nitrided layer. Below the nitrided layer, tempering occurs relatively quickly and a soft layer is formed with a hardness below 400 HV.

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

Welding Technology Review ◽

10.26628/wtr.v91i2.1020 ◽

2019 ◽

Vol 91 (2) ◽

Cited By ~ 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.

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FEM Analysis for Tangible Component Production

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.611-612.1657 ◽

2014 ◽

Vol 611-612 ◽

pp. 1657-1664 ◽

Cited By ~ 2

Author(s):

Mario Rosso ◽

Ildiko Peter

Keyword(s):

Material Flow ◽

Hot Forging ◽

Fem Analysis ◽

Forging Process ◽

Die Life ◽

One Step ◽

Hot Forging Process

In high temperature metal forming techniques, analysis of the material flow and deformation as well as wear distribution during forging are very important, because they are directly correlated to the quality of the final component and to the productivity and die life. In this paper a commercially available Finite Element Method based simulator, namely Transvalor Forge 2008©, is used to numerically investigate on the effects of the various parameters on the mode of the failure of dies during hot forging. The exploration has the purpose to evaluate the possibility and related benefits of the advancement from a traditional hot forging process to a modern thixoforging one in the case study of steel-made steering pistons production. As a first step, the part related to the hot forging process is in detailed analyzed, in order to get an exhaustive description of the role of the different parameters. One step and two step solutions are proposed and discussed.

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One Action Press Forming of Helix Bevel Gear by Using Multi-Cylinder Press and Die Heating System

International Journal of Automation Technology ◽

10.20965/ijat.2018.p0767 ◽

2018 ◽

Vol 12 (5) ◽

pp. 767-774

Author(s):

Katsuaki Nakamura ◽

◽

Hiroshi Koresawa ◽

Hiroyuki Narahara

Keyword(s):

Hot Forging ◽

High Hardness ◽

Heating System ◽

Bevel Gear ◽

Cold Forging ◽

Machining Time ◽

Forging Process ◽

Forged Parts ◽

Almost All ◽

Forging Press

In the case of a complex shaped helix bevel gear, the forging of complete gear tips is very difficult to achieve. In almost all cases, tooth profile is finished by cutting machine from simple shaped forged parts, therefore requiring considerable machining time and cost. However, there are many approaches to forging. Forging is mainly classified as hot and cold forging, and uses a single motion press. In the case of hot forging takeoff of products from die is difficult by the cooling shrinkage from die and accuracy of products is lower level than cold forging. In addition, in the case of cold forging, a complicated shape is difficult to achieve based on the lack of ductility of the materials. To realize a helix bevel gear using a single forging operation, we applied a tool heating system and three-axis forging press. The tool heating system is applied to prevent a temperature decrease in the material by contact between the tool and forging material during the forging process. Further, to optimize the forging direction and timing, we used a three-axis forging press. We confirmed good forging capability of this special forging process, as well as the high precision of the forged parts. Moreover, through the thermo-mechanical control of steel and the tool temperature, the forged parts showed good mechanical properties, such as high hardness.

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Comparison of different sensor technologies to monitor a forging process

10.25518/esaform21.1475 ◽

2021 ◽

Author(s):

Camille Durand ◽

Ludovic Freund ◽

Cyrille Baudouin ◽

Régis Bigot ◽

Jean-Dominique Guérin

Keyword(s):

Numerical Simulations ◽

High Temperatures ◽

Hot Forging ◽

Experimental Results ◽

Sensor Technology ◽

Harsh Environment ◽

Easy Task ◽

Forging Process ◽

High Speeds ◽

Comparison With Experiments

Nowadays, numerical simulations are more and more used in forging industry, and their predictability is validated through a comparison with experiments. But sometimes simulations and experiments provide significantly different results. And quite often, the models implemented in simulations are taken for responsible of this divergence with experimental results. But results experimentally obtained can also be discussed. Depending on the operatory conditions, and the type of sensor used, measured results can be different. Moreover, integrating sensors is not an easy task for forging processes, as sensors could be exposed to harsh environment with high speeds, high forces, high temperatures, radiations, … In this paper data for displacement and force measured by different sensors are compared. Advantages of different sensor technology are discussed in the case of hot forging processes performed with energy piloted machines.

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Advanced Complex Analysis of the Thermal Softening of Nitrided Layers in Tools During Hot Die Forging

10.20944/preprints202012.0019.v1 ◽

2020 ◽

Author(s):

Jakub Krawczyk ◽

Paweł Widomski ◽

Marcin Kaszuba

Keyword(s):

Numerical Modeling ◽

Surface Layer ◽

Laboratory Tests ◽

Complex Analysis ◽

Nitrided Layer ◽

Thermal Softening ◽

Effect Of Temperature ◽

Destructive Effect ◽

Forging Process ◽

Influence Of Temperature On

This article is devoted to the issues of thermal softening of materials in the surface layer of forging tools. The research covers numerical modeling of the forging process, laboratory tests of tempering of nitrided layers and the analysis of tempering of the surface layer of tools in the actual forging process. Numerical modeling was supported by measuring the temperature inside the tools with a thermocouple inserted into the tool to measure the temperature as close to the surface as possible. The modeling results confirmed the possibility of tempering the die material. The results of laboratory tests made it possible to determine the influence of temperature on tempering at different surface layer depths. Numerical analysis and measurement of surface layer microhardness of tools revealed the destructive effect of temperature during forging on the tempering of the nitrided layer and on the material layers located deeper below the nitrided layer.

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