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Zbigniew Gronostajski Marek Hawryluk Marcin Kaszuba Paweł Widomski Jacek Ziemba 《International Journal of Automotive Technology》2017,18(4):653-662
This study is focused on tools used in the industrial hot forging process of a front wheel forging (eventually–gear wheel) manufactured for the automotive industry. Four different variants were applied for the tools: 2 die inserts were coated with two different hybrid layers (GN + PVD type), i.e. AlCrTiN and AlCrTiSiN, 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 reliminary analysis, that various degradation mechanisms are predominant. Microstructural 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 (area A), thermo-mechanical fatigue and wear occurred, while in the area of the bridge insert (area B), only abrasive wear could be observed. For these areas (A and B), the loss of material was determined separately. In area A for the inserts with hybrid layer GN+AlCrTiSiN and gas nitrided, an intensive increase of wear took place, which was not observed for the pad welded and GN+AlCrTiN layer insert, for which, together with the increase of the forging number, a proportional growth of the loss of material occurred. In area B the weakest results were obtained for the insert with GN+AlCrTiSiN layer, while wear of other die inserts grew similar and proportional. 相似文献
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Rokicki Bartlomiej Haddad Eduardo A. Horridge Jonathan M. Stępniak Marcin 《Transportation》2021,48(2):747-772
Transportation - Since its EU accession, Poland has invested strongly in the development of fast road transport network. As a result, the total length of modern, high-speed roads has increased from... 相似文献
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Moyano Amparo Stępniak Marcin Moya-Gómez Borja García-Palomares Juan Carlos 《Transportation》2021,48(6):3301-3324
Transportation - This paper aims to evaluate the impacts of the economic context on traffic congestion and its consequential effects on private vehicle accessibility. We conduct a long-term... 相似文献
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