Wyniki wyszukiwania - Biblioteka Nauki

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The Use of 3D Scanning Methods to Evaluate the Hybrid Layer Used in Forging Tools in Order to Improve their Durability

100%

Gronostajski Z. , Hawryluk M. , Kaszuba M. , Widomski P. , Ziemba J. , Smolik J.

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2017

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tom Vol. 62, iss. 3

1549--1558

EN

This study is focused on tools used in the industrial process of hot forging of a front wheel forging (gear wheel) manufactured for the automotive industry. Five different variants were applied for the tools: 3 die inserts were coated with three different hybrid layers (PN + PVD type), i.e. AlCrTiN, AlCrTiSiN and CrN, one insert was only nitrided, and one was pad welded, to improve tool durability. The tool wear was analysed and represented by the material degradation on the working surface, based on the 3D scanning and the material growth of the periodically collected forgings. Additionally, the scanned tools were divided into two areas, in which it was found, based on the analysis, that various degradation mechanisms are predominant. Microstructural tests and hardness measurements of the analyzed tools were also performed. Based on the results, it was found that, in the central part of the die insert, thermo-mechanical fatigue, abrasive wear and plastic deformation occurred, while in the area of the bridge insert, only abrasive wear could be observed. For these areas, the loss of material was determined separately. It was established that the use of the GN+CrN and GN+AlCrTiN hybrid layers on forging tools improves their durability, while the best results in the central area were observed on the tool with the GN+CrN layer, which is the most resistant to thermo-mechanical fatigue. In the second analyzed area, good wear resistance occurred on GN+CrN, GN+AlCrTiN and pad welded inserts, for which, together with the increase of the forging number, a proportional, slight growth of the loss of material occurred.

2

Zastosowanie warstw hybrydowych na narzędziach do kucia na gorąco odkuwki koła czołowego

86%

Gronostajski Z. , Kaszuba M. , Hawryluk M. , Będza T. , Włodarczyk W. , Smolik J.

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tom z. 253

101--106

PL

W pracy przedstawiono opis zjawisk zachodzących na powierzchni matryc do kucia na gorąco odkuwki koła czołowego, gdzie w celu poprawy ich trwałości zastosowano warstwy hybrydowe. Analizie poddano narzędzia wykonane ze stali WCLV stosowane w drugiej operacji kucia. Oceniono skuteczność zastosowanych warstw hybrydowych w zwiększaniu trwałości analizowanych narzędzi. Przeprowadzone badania wykazały, że modyfikowanie właściwości warstwy wierzchniej przez zastosowanie technik hybrydowych typu warstwa azotowana i powłoka PVD daje możliwość efektywnego zwiększenia trwałości narzędzi kuźniczych w analizowanym procesie.

EN

The article presents a description of the phenomena occurring on the surface of dies with hybrid layer for hot forging of front wheel. Analysis was carried out on the tools made of steel WCLV used in the second operations. The effectiveness of the hybrid layer for improving the durability of analyzed tools has been evaluated.

3

Directions for increasing conical picks’ durability

72%

Bołoz Ł.

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tom Vol. 2, Iss. 1

277--286

EN

Conical picks are cutting tools used in many branches, in particular in the mining, road construction and building branch. Contact with the excavated face causes their constant wear, which is an unfavorable but unavoidable process. Milling heads of working machines are equipped with several dozen conical picks, and mining in abrasive or hardly accessible rocks can reduce their life to a few hours. It is in the interest of both users and producers to increase their durability, as tools replacement, apart from purchase and logistic costs, results in machine downtimes. In the article various solutions of conical picks, their construction, dimensions and materials used have been discussed. Technical procedures applied to increase the durability of conical picks and their regeneration as well as methods of extending the life of picks working in difficult conditions have been presented. Two author’s methods of extending the life of picks working in difficult conditions, covered by a patent application, have also been presented. The first solution involves ensuring an uninterrupted rotational movement of the pick in the holder. Patent claims include an innovative method of equipping the additional sleeve integrated with the holder with a rotational bearing, which enables a continuous rotation of the pick. The tool equipped with a bearing generates much lower movement resistance than the standard mounting. The holder is designed to mount classic commercial picks. What is important, the pick replacement does not require interfering with the bearing assembly. The second solution concerns the manner of protecting the working part of the pick by means of a special element made of an abrasion resisting material. This element is the pick tip, the geometry of which varies from the commonly applied posts made of sintered carbide. In this solution, the tip has a shape corresponding to the form of conical pick’s wear, which causes that its steel body does not wear. Moreover, there is a possibility of applying a mobile, rotational mounting of the tip to the body.

4

Chemical-heat treatment of materials used for fabrication of tools and effects of this treatment to durability of tools

58%

Němec J. , Fajt J.

Journal of Achievements in Materials and Manufacturing Engineering

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2014

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tom Vol. 62, nr 2

88--92

EN

Purpose: The aim of the presented researches is development and design of fluid bed mixed by hot gas. The fluid bed is designed to the chemical-heat treatment with thermo-active powders. This treatment is used for tools and mechanical parts. Design/methodology/approach: Contribution is focused on increasing of the cutting property of tools made from high speed steel by chemical-heat treatment. Precisely nitrocarburizing at a fluid mixture of a thermo-active powder was used. Possibilities of this method of nitrocarburizing are described in the contribution, especially advantages, disadvantages and effects on the durability of the tools and mechanical parts. Findings: The material test have showed that the surface layer made by fluid process have better properties than layers made by classical method. But the verification test of the tools with nitrocarburizing did not show increasing of durability. Research limitations/implications: Layer of nitrocarburizing was evaluated by material tests as nanoindentation and scratch-test. Moreover working test of the tools and parts was made for detection of the effect of the fluid-nitrocarburizing to the durability of the tools and properties of the parts. Originality/value: The chemical-heat treatment with fluid bed extends durability of thermo-active powders against treatments without fluidization. Other advantage of the treatment with fluidization is reducing of the energy consumption of the technological process.