Publications by authors named "Jan Marzec"

This article presents research results regarding the development of a new manufacturing technology for an element assigned to belt conveyor flights in the extractive industry through hot die forging (of a forging with a double-sided flange) instead of the currently realized process of producing such an element by welding two flanges onto a sleeve or one flange onto a flange forging. The studies were conducted to design an innovative and low-waste technology, mainly with the use of numerical modelling and simulations, partially based on the current technology of producing a flange forging. Additionally, during the development of the forging process, the aspect of robotization was considered, both in respect of the forging tools and the process of transportation and relocation of forging between the impressions and the forging aggregates.

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The article discusses the phenomena and destructive mechanisms occurring on the surface of 1.2344 steel dies used during the hot forging of disc-type forgings. Preliminary research has shown that gas nitriding alone, used so far, is insufficient due to the occurrence of destructive mechanisms other than abrasive wear, such as thermal and thermomechanical fatigue, which cause the average durability of such tools to be approximately 5000 forgings.

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This study refers to an analysis of the durability of forging tools applied in the second operation of producing a valve forging from the chromium-nickel steel, NC3015. Due to the extreme working conditions of the tools, caused by cyclic thermo-mechanical loads, the average durability of tools made from tool steel WLV (1.2365) equals about 1500 forgings.

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This article presents the results of a comparative analysis performed with respect to the wear of tools used for the extrusion of a clay strand (for ceramic roof tile) made from two materials: steel NC11LV and steel Hardox 600. The aim of the studies was to determine the causes and mechanisms of wear as well as to evaluate the possibility of choosing the optimal material, mostly in respect to its resistance to intensive wear as well as an increase in the operation time. The results of the conducted investigations included: an analysis of the technology, thermovision measurements of the forming process, a macroscopic analysis combined with 3D scanning of the worn tools, ball-on-disc tests of the sliding wear resistance and hardness measurements.

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This study performs a complex analysis and review of the currently applied methods of inductively heating the charge material in hot die forging processes, as well as elaborates and verifies a more effective heating method. On this basis, a device for inductive heating using variable frequency inductors was designed and constructed, which made it possible to reduce the scale and decarburization with respect to the heater used so far. In the first place, the temperature distributions in the heater in the function of time were modeled with the use of the CEDRAT FLUX software.

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The study performs a comparative analysis of the wear of tools made of two wear-resistant materials: steel Hardox 600 and NC11LV, used in the process of forming a band for roofing tiles. The analyses were to allow the assessment of the possibility of replacing the standard material for tools in this process with a much less expensive tool steel for cold work after heat treatment (with a large number of carbides), as an alternative material dedicated to tools resistant to intense abrasive wear. The performed investigations included a macroscopic and geometrical analysis with the use of 3D scanning, microstructural analyses conducted by means of a light microscope, as well as an analysis of the topography of the working areas of the tools with the use of SEM, and microhardness tests.

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