Bányászati és Kohászati Lapok - Kohászat, 2019 (152. évfolyam, 1-6. szám)

2019 / 1. szám

A kiadvány a FÉMALK Zrt. támogatásával jelenik meg TARTALOM [ FROM THE CONTENT Bevezető ■3 Beszélgetés dr. Hatala Pállal, Egyesületünk elnökével Vaskohászat ■E A. Franceschini - F. Ruby-Meyer - F. Midroit - B. Diawara - S. Hans- T. Poulain - C. Trempont - E. Henault: Gyengén öt­vözött acélok zárványvizsgálati technikái­nak áttekintése KE Mucsi András - Valkai Máté: Hökezelési és alakváltozási paraméterek összefüggé­sei 42CrMo4 acélminőségnél Öntészet ma Bubenkó Marianna - Gyarmati Gábor - Fegyverneki György - Tokár Monika - Dúl Jenő: A szemcsefinomítás hatékony­ságának minősítése termikus analízissel KE Walczer Csaba - Bárdos András: Nyo­másos rotoröntvény formatöltési idejének optimalizálása Fémkohászat KS Bereczki Péter - Fehér Jánosné - Bezi Zoltán - Köti Dániel: EN AW-8006-os alu­míniumötvözet melegen hengerelt szem­cseszerkezetének optimalizálása végesele­mes és fizikai szimuláció alkalmazásával Weil Jurecska Tamás: Optikai-, konfokális mik­roszkópia és infravörös spektroszkópia al­kalmazása alumíniumtermékek felületi vizs­gálatára Anyagtudomány KE Réger Mihály: Hengerelt lapostermékek középvonali dúsulása M -ч Benke Márton - Hlavács Adrienn - Pillér Imre - Mertinger Valéria: Lemezek fülese­­dése és a {hOO} polusábrák közötti kapcsolat Felsőoktatás KE Farkas Ottó: A Vaskohászati Tanszék az Alma Mater Selmecbányáról Sopronba tör­ténő átmenekítése idején t; „Selmec, Téged soha nem feledtünk!” KE A Miskolci Egyetem hírei Hírmondó KS Szent Borbála-napi központi ünnepség Emlékeztető OMBKE választmányi üléséről KE 10. Nemzetközi Clean Steel Konferencia XXIV. Szent Borbála Napi Kohász Szak­estély ni Budapesti vaskohászok kirándulása El XIV. Ózdi Hagyományápoló Szakestély KE Tisztelgés professzoraink és firmáink előtt 1? Amikor még fújt a gyár - 150 éves a Diós­győri Vasgyár E Alumíniumban utazunk E Pöschl-Selmeczi Vilmos élete és munkás­sága Köszöntések KE Nekrológok A. Franceschini - F. Ruby-Meyer - F. Midroit - B. Diawara - S. Hans - T. Poulain - C. Trempont - E. Henault: Overview of Cleanliness Assessment Techniques for Low Alloyed Steel Grade...........4 Steel properties are influenced by the amont, size and distriburion of non-metallic inclusions. Because of the small size and amount of inclusions the investigation of these parameters is difficult and complicated. The 2 and 3 dimensional size distribution of inclusions in air-melted and in remelted steel were investigated using microscopic (LOM, SEM) and ultrasound measurement. Results were confirmed by fatigue tests. Mucsi A. - Valkai M.: Relation between the heat treatment and deformation parameters of 42CrMo4 steel grade............................................7 The steel grade investigated in this study is frequently used for engineering parts subjected to fatigue or wear. Beside its good quenchability it can be advantageously used for nitriding, moreover this steel grade is not too sensitive to temper brittleness. According to the technical literature, the behavior of the material during plastic deformation parameters could be different even in case of the same mechanical parameters. In this paper, the deformation behavior of differently heat treated specimens is outlined. Bubenkó M. - Gyarmati G. - Fegyverneki Gy. - Tokár M. - Dúl J.: The Evaluation of the Efficiency of Grain Refinement by Thermal Analysis.......11 In this research thermal analyses of melts of different alloys used for gravity die cast cylinder heads were carried out. Our experiments which were competed in factory conditions had the aim to examine the effect of adding small amount of AITÍ5B1 supplementary grain refining pre-alloy on primary crystallisation. Different evaluating methods of thermal analysis were tested and compared. Results proved that dosing small amount of grain refining alloy was found favourable in the foundry production practice. Walczer Cs. - Bárdos A.: Optimizing the filling time of the die-cast rotor casting.......................16 Today, the demand for electric-powered vehicles has increased significantly. For this reason, more and more cast-rotors are required. The casting time of the rotor casting must first be determined. The calculation methode for conventional castings in not applicaable to determine the casting time of die-cast rotors. In this article, we will show how to calculate the casting time of a rotor, which is confirmed by the results of experimental casting. Bereczki P- Fehér J. - Bézi Z. - Kóti D.: Grain structure optimization of hot rolled EN AW-8006 aluminium alloy using finite element and physical simulation ............................................20 Regarding to the hot rolling of unalloyed and low­­alloyed aluminium alloys, one of the main issue is to avoid the heterogeneity of the grain structure. In this publication, some results of an experimental and modelling activity were demonstrated which is aimed to improve the grain structure homogeneity in the hot rolled slab from EN AW-8006 alloy. These slabs show layered microstructure already in the early stage of the hot rolling process. According to our hypothesis, this phenomenon can be moderated or eliminated using larger reductions and decreasing the rolling speed. The finite element analysis and the physical modelling of the thermomechanical loading for the original and the modified hot rolling schedules showed that the early-stage formation of layered microstructure can be moderated. Based on these principles, the industrial trials using the modified hot rolling schedule results in a strip with almost homogeny, partially recrystallized microstructure. Jurecska T: Application of Optical-, Confocal­­microscopy and Infrared Spectroscopy for Sur­face Examination of Aluminium Products......27 With the development of technology, the customer expectations have also increased. To guarantee the aluminum products surface quality requirements, improvement of them, and for finding the reason of faults, are being continuously developed more precise measuring equipment. In this publication some industrial surface faults are presented faults from the industrial environment and their examination from several sides: the optical microscopy for high­­magnification surface and sectional images, the confocal microscopy for surface scanning for three dimensional representations, and Infrared Spectroscopy which is used directly at the surface to investigate the organic contaminants. In addition the combination possibility of these methods will be demonstrated. Réger M.: Centerline inhomogeneity of flat products ................................................................33 One of the most unpredictable defects of cast slabs is the centerline segregation. The centerline segregation in slabs develops in a complex way; it is connected partly to the macrosegregation and partly to the shrinkage of solidifying melt. As a result of these processes, the centerline segregated part of the slab will have a different chemical composition compared to the average composition and/or it will contain shrinkage holes, discontinuities and inclusions. After the solidification process during hot rolling the complex shaped interdendritic holes will be closed as a function of applied strains. The difference in chemical composition will remain even after the slab has spent several hours at over 1000 oC in the soaking furnace before hot rolling. Hot rolled products (heavy plates, strips) with centerline segregation will contain, depending on the solidification and technological parameters, a middle part with a chemical composition dissimilar to the average (i.e. in case of St52 grade the segregated area can be characterized by a carbon content of 0.3- 0.5 wt% and manganese content of 1.7-1.9 wt%). According to industrial experiences, the segregation level (including the carbon content) can hardly be decreased by heat treatment. Benke M. - Hlavács A. - Pilier I. - Mertinger V.: The correlation between sheet earing and {h00} pole figures ............................................................36 In the present manuscript, a novel method is introduced which is suitable to predict the mechanical anisotropy, namely the relative ear height of sheet semi-products. The method - unlike other, more complex methods - does not rely on texture components or the ODF, but on pole figures of the {h00} reflections arid does not require additional mechanical tests. The method was applied on rolled then annealed AI sheets with 0,3 mm thickness. Comparing the predicted ear heights to measured ear heights a good correlation was found. Öntészet rovatunkat az 1950-ben indí­tott és 1991 -ben megszűnt önálló szak­lap, a BKL Öntöde utódjának tekintjük. • • Szerkesztőség: 1051 Budapest, Október 6. utca 7., III. em. • Telefon: 06-1-201-7337 • • E-mail: bkl.kohaszat@gmail.com • • Felelős szerkesztő: Balázs Tamás • • A szerkesztőség tagjai: dr. Buzáné dr. Dénes Margit, dr. Dévényi László, dr. Dúl Jenő, dr. Harcsik Béla, dr. Kóródi István, Schudich Anna, dr. Szombatfalvy Anna, dr. Tardy Pál, dr. Török Tamás • • Kiadó: Országos Magyar Bányászati és Kohászati Egyesület • Felelős kiadó: dr. Hatala Pál • • Nyomja: Press+Print Kft. 2340 Kiskunlacháza, Gábor Áron u. 2/a • HU ISSN 0005-5670 • Belső tájékoztatásra, kereskedelmi forgalomba nem kerül. • A közölt cikkek fordítása, utánnyomása, sokszorosítása és adatrendszerekben való tárolása kizárólag a kiadó engedélyével történhet. • Interneteim: www.ombkenet.hu/bkl/kohaszat.html

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