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1
Content available remote Selection of the best phase transformation model for optimization of manufacturing processes of pearlitic steel rails
Kuziak Roman, Pidvysots'kyy Valeriy, Pernach Monika, Rauch Lukasz, Zygmunt Tomasz, Pietrzyk Maciej
Archives of Civil and Mechanical Engineering
|
2019
|
Vol. 19, no. 2
535--546
EN
Selection of the best model for simulation of manufacturing processes of pearlitic steel rails was the objective of the paper. Achieving a proper balance between its predictive capabilities and computing costs was used as a criterion. Review of the pearlitic transformation models was performed and modification of the JMAK equation was selected for further analysis. Empirical models were developed to describe microstructure and mechanical properties of rails. Dilatometric tests were performed to supply data for identification of the phase transformation model. Physical simulations of various thermal cycles were performed to validate and verify the models. Finite element (FE) simulations of the hot rolling provided distributions of the temperature and the austenite grain size at the cross section of the rail, which were used as an input for modelling of phase transformations during cooling. Accelerated cooling by a cyclic immersion of the rail head in the polymer solution was considered as a case study. Performed simulations confirmed good predictive capabilities of the model.
2
Content available remote Struktura doczołowych złączy stali ze staliwem zgrzewanych rezystancyjnie
Żurek Z.
Przegląd Spawalnictwa
|
2018
|
R. 90, nr 7
42--45
PL
W pracy przedstawiono wyniki badań mikrostruktury złączy zgrzewanych stali R260 ze staliwem GX120Mn13 i stalą X10CrNi18-8. Analizowane materiały posiadały charakterystyczne dla siebie rodzaje mikrostruktury. W przypadku złączy zgrzewanych w okolicy linii zgrzania zaobserwowano zjawisko wnikania ciekłego metalu po granicach ziarn, co spowodowane jest niższą temperaturą topnienia materiałów o strukturze austenitycznej w stosunku do stali perlitycznej. Ponadto w tym obszarze zidentyfikowano występującą niejednorodność składu chemicznego materiałów o strukturze austenitycznej związanych z wymieszaniem się materiałów podczas zgrzewania.
EN
The paper presents the results of investigation of the microstructure of welded R260 steel with GX120Mn13 cast steel and X10CrNi18-8 steel. The analyzed materials had characteristic microstructure types. In the case of welded joints next to the fusion line, the phenomenon of liquid metal penetration along grain boundaries was observed, which is caused by the lower melting temperature of austenitic materials in relation to pearlitic steel. In addition, the heterogeneity of the chemical composition of austenitic materials related to the mixing of materials during welding was identified in this area.
3
Content available The impact of operation of elastomeric track chains on the selected properties of the steel cord wires
Grygier D.
Eksploatacja i Niezawodność
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2017
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Vol. 19, no. 1
95--101
EN
The track running systems enable movement of heavy vehicles on unpaved and rough terrain, snow-covered, marshy or swampy surfaces, as well as overcoming natural or artificial barriers. The important structural component of the elastomeric tracks is a steel cord sunk in the elastomer creating the tread with the purpose of stiffening the structure, maintaining its proper deflection and giving the adequate resistance to tensile forces. The results of the studies presented in the work have shown that operation of the elastomeric track chains in conditions where they are continuously exposed to contact with foundation, frequent braking and bumping against roughness lead to damage of the steel cord material and a change in its mechanical properties.
PL
Gąsienicowe układy bieżne umożliwiają poruszanie się ciężkich pojazdów po powierzchniach nieutwardzonych oraz w trudnym terenie, zaśnieżonym, bagnistym lub grząskim, a także pokonywanie przeszkód naturalnych i sztucznych. Ważnym elementem konstrukcyjnym gąsienic elastomerowych jest stalowy kord, zatopiony w elastomerze tworzącym rzeźbę bieżnika, ma on na celu usztywnienie konstrukcji, zachowanie jej właściwego ugięcia oraz nadanie odpowiedniej odporności na siły rozciągające. Wyniki badań prezentowanych w pracy wykazały, że eksploatacja gąsienic elastometrowych w warunkach, w których narażone są na ciągłą styczność z podłożem, częste hamowanie oraz uderzenia w nierówności prowadzi do uszkadzania materiału stalowego kordu i zmiany jego własności mechanicznych.
4
Content available Analysis of the causes of damage to the wires of the steel belt of car tires
Grygier D.
Interdisciplinary Journal of Engineering Sciences
|
2016
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Vol. 4, no. 1
45--49
EN
The main when buying car tires we would like them to serve us as long as possible while the experts recommend their replacement after six years at the latest – is it really necessary? In this work the analysis of the impact of car tires operation on microstructure of the steel belt wires has been presented. The results of the presented research have proven that as a result of the complex stresses in the belt wire material the transverse cracks of individual cementite lamellae appear. The observed structural changes are a major cause of fatigue cracks development and finally result in breaking continuity of steel belt wires, breakthrough of the rubber layer and eventually damage to the tires, preventing their further work.
5
Content available The Effect of a Change in Recrystallization Annealing Time on the Properties and Structure of Cold-Drawn Wires
Grygier D., Rutkowska-Gorczyca M., Dudziński M.
Journal of Machine Engineering
|
2015
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Vol. 15, No. 1
90--97
EN
Although many heat treatment schemes have been developed for pearlitic steel, in the literature there is still little information about the influence of the different heat treatment parameters on the percentage, properties and morphology of the phases. Neither there is any information on matching the parameters, taking into account the different degree of deformation of the steel wires, the particular applications and operating conditions of the products. The aim of this research was to optimize the parameters of the interoperation annealing used during the cold plastic work-ing of pearlitic steel intended for cold-drawn wires. The results of the hardness measurements and microscopic observations, presented in this paper clearly show that there is no need to apply long recrystallization treatments to small diameter wires. This finding is highly significant from the economic point of view and it clearly shows the importance of the individual matching of heat treatment parameters to specific industrial applications.
6
Content available The effectiveness of spheroidization pearlitic steel with regard to the degree of plastic deformation
Grygiel D., Dudziński W, Gerstein G., Nürnberger F.
Interdisciplinary Journal of Engineering Sciences
|
2015
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Vol. 3, no. 1
6--9
EN
Pearlitic steels containing from some 0,8 to 0,95% C belong to the group of unalloyed steels of the quality class destined for cold drawing or rolling, they find application mainly as wires used for reinforcement of tires, hoses or rope production. However this group of steels characterized low machinability, as a consequence of presence hard plates of cementite, the intervention ameliorative this property is spheroidizing annealing. The object of the tests presented in paper was wires of pearlitic steel obtained after the successive stages of cold plastic working. The aim of the tests was to show that the condition of the material and mainly degree of plastic deformation have a clearly influence on the effectiveness of pearlitic steel spheroidization.
7
Content available The effectiveness of recrystallization high carbon steel with regard to the condition of material
Grygier D.
Interdisciplinary Journal of Engineering Sciences
|
2015
|
Vol. 3, no. 1
20--24
EN
The main aim of the studies presented in paper was to optimize the parameters of the recrystallisation annealing process used in the course of cold plastic working of high carbon steel for patented wires. Object of the research described in the work was eutectoid steel of 0,8% content of C designated for production of colddrawn wires applied for reinforcement of car tires, hoses and ropes. The results of tests show that the condition of the material and mainly degree of plastic deformation has a clearly influence on the effectiveness of pearlitic steel recrystallisation.
8
Content available Microstructure Evaluations in Pearlitic Steels Wires Resulting from Modification of the Interoperation Annealing Process
Grygier D., Rutkowska-Gorczyca M., Jasiński R., Dudziński W., Gershtein G.
Journal of Machine Engineering
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2014
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Vol. 14, No. 1
53--62
EN
Pearlitic steels containing from some 0.8 to 0.95% C belong to the group of unalloyed steels of the quality class destined for cold drawing or rolling. At the same time, the steels are characterised with particularly low share of non-metallic inclusions and limited contents of chromium and nickel, which extend the pearlite reaction time. The pearlitic steel in the annealed state has the highest strength in relation to other unalloyed steels, therefore she have found application mainly as wire rods for springs, wires for car tire reinforcement and cables. However one of the issues widely discussed in literature is cracking of pearlitic steel subjected to plastic working, caused by high brittleness of the lamellar precipitations of hard cementite. This issue is extremely important because it affects significantly reduce fatigue strength. The paper presents proposals to modify the process of interoperation annealing in order to eliminate this problem.
9
Content available remote Application of the diffusion equation to modeling phase transformation during cooling of pearlitic steel
Pernach M.
Computer Methods in Materials Science
|
2014
|
Vol. 14, No. 4
228--235
EN
Exploitation properties of rails are formed by controlled heat treatment of the head of the rail carried out after rolling. Complex cooling schedules have to be applied to obtain required microstructure and properties of rail steels. Design of these cooling schedules should be supported by numerical simulation. This, however, requires advanced phase transformation models which are able to predict not only average parameters of the microstructure but also morphology of the pearlite and carbon distribution in this structural component. Therefore, numerical model of pearlitic transformation is proposed in this work. The model was based on the solution of the carbon diffusion equation. The boundary conditions were determined assuming local thermodynamic equilibrium. Location of the interface in each time step was predicted from the condition of mass conservation. The created model allowed determining of the interlamellar spacing and carbon distribution in austenite for different cooling cycles. The results of analysis can be used to predict the strength and hardness of the steel.
PL
Własności wytrzymałościowe szyn kształtowane są na drodze kontrolowanego procesu obróbki cieplnej główki szyny prowadzonej po procesie walcowania. Aby uzyskać wymaganą mikrostrukturę i własności stali należy zastosować złożone cykle cieplne. Zaprojektowanie tych cykli powinno być wspierane numerycznym modelowaniem, co wymaga zastosowania zaawansowanych modeli przemian fazowych. Modele takie powinny przewidywać nie tylko średnie parametry mikrostruktury, ale także morfologię perlitu i rozkład stężenia węgla. W pracy przedstawiono model przemiany perlitycznej zachodzącej podczas kontrolowanego chłodzenia. Model ten oparto na rozwiązaniu równania dyfuzji z ruchomą granicą międzyfazową. Warunki brzegowe modelu wyznaczono na podstawie lokalnej równowagi termodynamicznej. Model pozwolił na określenie wielkości płytek cementytu i ferrytu, oraz rozkładu stężenia węgla w austenicie dla różnych cykli chłodzenia. Otrzymane wyniki mogą posłużyć do określenia twardości i wytrzymałości stali.
10
Content available remote The role of surface and bulk structure in the thermopower characterization of perlitic carbon steels
Szabo A., Lovas A.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 2
349-354
EN
For the study of stress state and the level of heat treatment in engineering alloys, the thermo power (S) measurement is proposed as an acceptable method after a suitable calibration. In this paper, we focus on the determination of the influence of phase relations from the point of view of thermo power using industrial pearlitic carbon steels. The results of thermoelectric power measurements reported in this paper do confirm the applicability of S (T) measurements as non-destructive testing of quench hardening in pearlitic steels.
11
Content available remote The multi-scale FEM simulation of the drawing processes of high carbon steel
Milenin A., Muskalski Z., Wiewiórowska S., Kustra P.
Journal of Achievements in Materials and Manufacturing Engineering
|
2007
|
Vol. 23, nr 2
71-74
EN
Purpose: The influence of cementite lamellas orientation on mechanical and technological properties of wire experimentally show up during investigation of drawing processes with change the direction of drawing between passes. The purpose of this paper is to develop a mathematical model of cementite and ferrite deformation during drawing processes and receive an information about transformation of a pearlitic structure of wire during drawing. Design/methodology/approach: The wire drawing processes was investigated in two levels - using the 2-dimensional rigid-plastic finite element method (macro-level) and modelling of a microstructure change (micro-level). In micro-level the process of deformation of representative volume element (RVE) is considered. The pearlitic colony deformation and stress-strain state in RVE is modelled with help of the FEM. Research limitations/implications: The influence of initial cementite lamellas orientation on triaxity factor and localization of deformation in micro-level is investigated. The numerical simulation is shown a maximal non-uniform deformation of pearlite phases for the canting positions of the cementite lamellas relative the drawing direction. Practical implications: The results of article will be helpful for a fundamental understanding of pearlitic deformation during development of high strength steel wires for tire cord applications. Originality/value: A new model of two-phase grain deformation for wire drawing is proposed. The new conception of simulation of the boundary conditions for the RVE is based on the penalty method and uses a solution of the problem on macro-level.
12
Microstructural evolution in high strength pearlitic steel wires
Zelin M., Pilarczyk J.W.
Hutnik, Wiadomości Hutnicze
|
2007
|
Vol. 74, nr 1-2
115-117
EN
Recent increases in the strength of steel wire to 4000 MPa range provide new opportunities for weight reduction of products utilizing steel cord, particularly, automotive tires. Processing of this pearlitic steel requires control of microstructure yielding a high strength combined with a good fatigue and toughness. Major processes of microstructure evolution during wire drawing, including ferrite/ cementite lamellae thinning, changes in interphase interfaces, and non-uniformity of plastic flow have been characterized. Effect of these processes on steel wire strength and ductility is discussed.
PL
Ostatnio prowadzone prace badawcze dotyczące wzrostu wytrzymałości drutów ze stali do poziomu 4000 MPa, dostarczyły nowych możliwość obniżenia masy produkowanych kordów, szczególnie, obręczy koła. Proces technologiczny wytwarzania stali perlitycznych wymaga kontroli mikrostruktury płynięcia, wysokiej wytrzymałości z dobrymi własnościami zmęczeniowymi. Przedstawiono główny proces rozwoju struktury podczas procesu ciągnienia, włączając cienkie płytki ferrytu/cementytu, zmiany międzyfazowe, i niejednorodne zmiany płynięcia. Dyskutowano efekt wpływu tych zmian na wytrzymałość i plastyczność badanych drutów stalowych.
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