The cooperation of Russian and German metal forming scientific schools to develop the new energy-efficient materials and technologies

The future scientific orientation of Katedra PDSS is in the area of materials forming and materials development with a focus on efficient processes regarding the use of energy and resources. Current research in the department PDSS is based on fundamental works on thermo-mechanical treatment of metals and on the modeling of nano-materials, rolled material and medical materials. This includes research on the relevant microstructural and macroscopic effects on the materials behavior. Together with its international research partners PDSS has excellent foundations for experimental research as well. With its international focus and its educational programs for students and skilled employees PDSS is an important partner of the Russian metal processing industry which supports Russian companies to compete on a world-class level

Concept of heat treatment and reversed hot strip rolling of magnesium

The production of magnesium strips, based on a twin-roll casting (TRC) and Hot Strip Rolling, has a promising application especially in automobile industry. Recently, the TRC line extends by further rolling mills to produce strips with fewer thicknesses. The additional rolling requires re-heating of the TRC strip coil to improve the deformation properties. The heating process affects the microstructure and final properties of the strips. Therefore, it is important to control the heat treatment process. The aim of this study is to create a bundle of models to calculate the temperature development in process of magnesium strip production. The first model calculates the temperature distribution in the TRC magnesium coils during pre-heating process and after rolling. Furthermore, the extend first model will be included into the Hot Strip Rolling in order to analyze a temperature condition in coil during the rolling process. Additionally, in this modelthe microstructure influencing by deformation and heat treatment process will be furtherincluded. In this article, the concept of the model and current state of the work will be defined

Ultrahigh Strength Steel: Development of Mechanical Properties Through Controlled Cooling

Structural steels with very high strength are referred as ultrahigh strength steels. The designation of ultrahigh strength is arbitrary, because there is no universally accepted strength level for this class of steels. As structural steels with greater and greater strength were developed, the strength range has been gradually modified. Commercial structural steel possessing a minimum yield strength of 1380 MPa (200 ksi) are accepted as ultrahigh strength steel (Philip, 1990). It has many applications such as in pipelines, cars, pressure vessels, ships, offshore platforms, aircraft undercarriages, defence sector and rocket motor casings. The class ultrahigh strength structural steels are quite broad and include several distinctly different families of steels such as (a) medium carbon low alloy steels, (b) medium alloy air hardening steel, (c) high alloy hardenable steels, and (d) 18Ni maraging steel. In the recent past, developmental efforts have been aimed mostly at increasing the ductility and toughness by improving the melting and the processing techniques. Steels with fewer and smaller non-metallic inclusions are produced by use of selected advanced processing techniques such as vacuum deoxidation, vacuum degassing, vacuum induction melting, vacuum arc remelting (VAR) and electroslag remelting (ESR). These techniques yield (a) less variation of properties from heat to heat, (b) greater ductility and toughness especially in the transverse direction, and (c) greater reliability in service (Philip, 1978). The strength can be further increased by thermomechanical treatment with controlled cooling

Ректор ТПИ А. А. Воробьев - изобретатель электроимпульсного способа разрушения горных пород

Представлена история создания электроимпульсного способа разрушения горных пород ректором ТПИ А. А. Воробьевым

Simulacija višestupnjastog procesa valjanja plosnatih proizvoda

By means of numerical simulation of process it is possible to predict the global and local properties of profiles after each step of deformation. Determination of the influence of each certain stage in experimental way is rather cost-based and therefore resource-demanding. This is the reason why in the past years and decades took place the significant advancement of modeling in connection with the application of the numerical approach. On basis of physical approach it is possible for example to predict the development of material and properties of deformed working piece at every one by one following stage of deformation. The great necessity consists in creating of fast simulation systems, which can rapidly estimate the influence of parameters of deformation process on the properties of product and devices. The significant attention is dedicated to the calculation in real time so that In-Line-Simulation makes it possible to control and to operate the processes and devices.Pomoću numeričkog simuliranja procesa, moguće je predvidjeti ukupno i mjestimično svojstvo poslije svake provlake kod deformacije. Određivanje utjecaja svake pouzdane etape u eksperimentu je zapravo temelj cijene i dakle pitanje resursa. To je razlog da je prošlih godina i dekada došlo do značajnijeg modeliranja povezanih s primjenom numeričkog pristupa. Na temelju fizikalnog pristupa moguće je na primjer predvidjeti stanje materijala i svojstava oblikovanih komada u svakom kao i u slijedećem stupnju deformacije. Visoki zahtjevi sadrže ustrojstvo brzih simulacionih sustava, pomoću kojih je moguće brzo prosuditi utjecaje deformacionih procesa na svojstva proizvoda i unapređenje. Značajna pozornost je posvećena izračunu stvarnog vremena tako da lanac simulacije ostvari mogućnost kontrole i unapređenje datih procesa

Razvoj procesa, postrojenja i proizvoda u valjaonicama čeličnih šipki i žice

Der Bedarf an Stabstählen und Drähten in Art, Menge und Qualität hat sich in der Vergangenheit wesentlich verändert. Die Fortschritte in der Walzwerkstechnik waren und sind ausschlaggebend, daß bemerkenswerte Qualitätsverbesserungen anvisiert und erzielt werden konnten. Für die Zukunft kann vor allem eine weitere Verschärfung der Maßstäbe an die Produktqualität prognostiziert werden. Technologisch kommt bei allen Stählen der werkstoffgerechten Temperaturführung beim Walzen eine besondere Bedeutung zu. Die Zuverlässigkeit der Prozeßführung ist sowohl ausschlaggebend für das erreichbare Qualitätsniveau als auch für die Treffsicherheit, mit der die Qualitätsparameter bei den verschiedenen Walzerzeugnissen erzielt werden können. Mit Hilfe integrierter Prozeßmodelle, die die werkstoffspezifischen, verfahrens- und anlagentechnischen Besonderheiten gleichermaßen berücksichtigen, können Technologien simuliert, bewertet und optimiert, die Walzprozesse präzis gesteuert werden. Der wissenschaftliche Erkenntnisstand der Modellierung und Simulation beim Warmwalzen hat einen hohen Stand erreicht und ist nunmehr auch für das Walzen von Stabstahl und Draht relativ weit fortgeschritten. Er bietet die Basis für nachhaltige technisch-technologische Innovationen.Potreba za čeličnim šipkama i žicama različitih vrsta, količina i kakvoća znatno se promijenila od one ranije. Napredak u tehnici valjanja je bio i ostao od odlučujućeg značenja za sagledavanje mogućnosti primjetnog poboljšanja kvalitete i realizacije tog poboljšanja. Što se tiče budućih promjena možemo prije svega govoriti o daljnjem izoštravanju mjerila za utvrđivanje kvalitete proizvoda. tehnološki gledano, kod proizvodnje svih vrsta čelika veliki značaj se pridaje pravilnom dovođenju temperature. Pouzdanost u vođenju tog procesa ima jednako odlučujuću ulogu u dostizanju određenog stupnja kakvoće kao i sigurnosti postizanja parametara kakvoće za različite proizvode valjanja. Pomoću integriranih modela procesa koji uzimaju u obzir podjednako karakteristike specifične za neki materijal, za neki postupak i za tehničke osobitosti nekog postrojenja, mogu se simulirati tehnologije, procjenjivati njihova vrijednost i izvršiti njihova optimalizacija tako da se procesima valjanja može upravljati maksimalnom preciznošću. Znanost je u modeliranju i simulaciji toplog valjanja dostigla visoki stupanj pa je u tom smislu relativno daleko uznapredovala i u valjanju čeličnih šipki i žice. Takav stupanj znanosti pruža osnovu za trajne tehničko-tehnološke inovacije

Kvalitet putem deformacije

Die Qualitätsverbesserung bei gleichzeitiger Reduzierung der Herstellungskosten und Senkung des Fertigung-saufwandes sind nachhaltig vorgetragene Forderungen. Die Notwendigkeit der Produktionsumstellung auf eine prozessstufenarme Fertigung bei Beachtung sozialökologischer Aspekte wird immer eindringlicher nachgewiesen und verlangt. Viele Forschungsarbeiten zur Entwicklung von Werkstoffen und Werkstofftechnologien sind auf diese Zielstellungen ausgerichtet worden. Sie haben zur Verfahrensrationalisierung und Gütesteigerung beigetragen. Die erreichten Technologiefortschritte zur Herstellung von warmgewalzten Stabstählen und Drähten waren ausschlaggebend, dass deren Produktqualität und Gebrauchswert in bemerkenswerter Weise gesteigert werden konnten. Das hat sich in den nachfolgenden Industriezweigen in vielfältiger und sichtbarer Art günstig ausgewirkt. Sie sind dies Basis, noch höhere Qualitätsniveaus anzuvisieren.Poboljšanje kvalitete i istovremeno smanjivanje troškova proizvodnje i izrade su zahtjevi koji se stalno postavljaju. Nužnost preusmjeravanja proizvodnje na izradu bez stupnjevanih postupaka, pri čemu se vodi računa o socijalno-ekološkim aspektima, dokazuje se sve više i više, a ujedno se i sve više zahtijeva. Cilj mnogih istraživanja usmjeren je prema razvoju materijala i razvoju tehnologije materijala. Takva istraživanja su doprinijela racionaliziranju iskustva i poboljšanju kvalitete. Postignuti tehnološki napreci u proizvodnji toplo valjanih čeličnih šipki i žica bili su odlučujući za značajno povećavanje kvalitete proizvoda i uporabne vrijednosti. To se odrazilo na višestruko povoljan i vidljiv način na kasnije nastale industrijske grane. Oni su osnova sa koje se može stremiti prema višim razinama kvalitete

Scale development on steel during hot strip rolling

The paper presents a new method to describe and to predict the development of scale during metal formingprocesses, especially hot strip rolling processes. This is necessary because scale develops during all hotdeformation processes over 600 °C and affects the mass loss of the raw weight as well as the surface qualityof the semi-finished product. The main components of oxide scale at steel are wustite, magnetite, and hematitewith various volume fractions. A challenge for the correct characterisation of the total scale layer is theconsideration of the strong inhomogeneity with respect to the mechanical properties of each scale component.Owing to these differences, the deformation behaviour of the single oxide layers is diverse, too. As result ofhigh deformation stresses, the oxide scale cracks, however low deformation degrees can be compensated.Due to the high hardness of the oxides, the fragments are pushed in the raw material and influence the gripconditions in the rolling gap and the material flow. Because of this the Institute of Metal Forming developeda new method to determine the temperature dependent properties of the scale layers, which are relevant forthe arrangement of metal forming processes. The strategy was based on the use of pure powder of each scaleelement for the production of testing samples with different geometries (cylindrical and cubic samples) bycompression and heat treatment steps

Herstellung von Hochwertigen Bändern und Blechen aus Aluminiumwerkstoffen

Die Aluminiumproduktion is t weltweit in den letzten Jahren angewachsen. Für Deutschland ist ein besonders starker Anstieg des Sekundäraluminiumanteils charakteristisch. Mehrere Betriebe mussten die energieaufwändigere Primäraluminiumherstellung aufgeben bzw. auslagern. Dieser Trend hält an. Der Datenüberblick über Produktion und Verbrauch an Al beleuchtet die gegenwärtige Situation. Er wird ergänzt durch technische Angaben der Herstellung von Bändern in den Fertigungsstufen des Warm- und Kaltwalzens sowie der Wärmebehandlung. Die Versuchsanlagen zur experimentellen Simulation des Institutes als Voraussetzung für Aufstellung von Fortschrittstechnologien und die mathematische Modellierung werden beschrieben. Ergänzend werden ausgewählte Untersuchungsergebnisse mitgeteilt

Nova tehnologija proizvodnje magnezijevih traka i limova

A new production technology for magnesium strip, based on twin-roll-casting and strip rolling was developed in Freiberg Germany. By means of this economic method it is possible to produce strips in deep drawing quality with good forming properties in order to satisfy the request for low cost Mg sheets in the automotive and electronic industry. Both, coils as single sheets, were manufactured and rolled to a thickness of 1mm(0,5 mm). The technology of the new process and the properties of the twin-roll-casted material and the final sheets are presented.Nova tehnologija proizvodnje magnezijevih traka i limova. Nova tehnologija proizvodnje magnezijevih traka utemeljena dvostruko-valjanje-lijevanje i valjanje trake je razvijeno u Freibergu-Njemačka. Motri se, ovom ekonomičnom metodom je moguća proizvoditi trake za duboko izvlačenje, sa dobrim plastičnim svojstvima uz zadovoljavajući zahtjev za nisku cijenu Mg trake za automobilsku i elektronsku industriju. Oboje, svitak i pojedinačne trake su poizvedene i valjane do debljine stjenke 1mm(0,5 mm). Prikazuje se tehnologija novog postupka i svojstva dvostrukog valjanog-lijevačkog materijala i završnih traka