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1

Deformation behaviour of high-manganese steel with addition of niobium under quasi-static tensile loading

Jabłońska Magdalena Barbara, Jasiak Katarzyna, Kowalczyk Karolina, Bednarczyk Iwona, Skwarski Mateusz, Tkocz Marek, Gronostajski Zbigniew

Materials Science Poland

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2022

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Vol. 40, No. 3

1--11

EN

In this paper, the heat generated during deformation under the static testing of high-manganese TWIP steel with addition of niobium was determined. The research combined the interaction of heat generated during deformation, mechanical properties, hardness and microstructure. Temperature and strain were measured simultaneously using infrared (IR) thermography and digital image correlation (DIC) method. The average temperature measured at the necked region equals 42°C at the strain rate of 0.001 s−1 and exceeds 100°C at 0.5 s−1. Therefore at large strains, a reduction in stress was observed. The course of the hardness change coincides very well with the strain changes, however, at the strain rate of 0.5 s−1 near to the necking area the hardness equals to 360 HV2, whereas at the lower strain rates it equals to 370 HV2. These changes are connected mainly with increase in temperature to >100°C

2

Theoretical and experimental analysis of high-manganese TWIP steel wire drawing process

Muskalski Z., Wiewiórowska S., Pełka M.

Hutnik, Wiadomości Hutnicze

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2013

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Vol. 80, nr 11

748--751

EN

In the work on the way of experimental analysis the influence value of single reduction for multistage drawing process on mechanical properties of drawn wires made from high-manganese TWIP steel was shown. In the aim of demonstration reasons the change of mechanical properties the computer simulation of drawing process with the use of computer program based on finite element method Drawing 2D was carried out. The structure evolution has been done and was shown that the decrease of tensile strength and yield strength after exceed the values of total reduction Gc%=80% was observed which can be cased by “strain softening” process.

PL

W pracy przedstawiono analizę eksperymentalną wpływu wielkości gniotu pojedynczego w procesie wielostopniowego ciągnienia na własności mechaniczne drutów oraz wykonaną z wykorzystaniem opartego na MES programu Drawing 2d, analizę teoretyczną procesu, mającą na celu wykazanie przyczyn zmian własności mechanicznych. Stwierdzono występujący po przekroczeniu gniotu całkowitego Gc%=80% spadek zarówno wytrzymałości na rozciąganie Rm, jak i umownej granicy plastyczności R0.2 spowodowany zjawiskiem „mięknięcia odkształceniowego”.

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Microstructure evolution after thermo-mechanical treatment of X11MnSiAl25-1-3 TWIP-type steel

Dobrzańska-Danikiewicz A., Borek W., Mazurkiewicz J., Jagiełło A.

Archives of Materials Science and Engineering

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2013

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Vol. 59, nr 1

14--21

EN

Purpose: The purpose of the article is to present the results of research of the effect of thermal and thermoplastic working on the structure of high-manganese austenitic TWIP steels. Design/methodology/approach: Plastometric tests were performed with DSI (Dynamic System Inc.) Gleeble 3800 instrumentation being the equipment of the Scientific and Didactic Laboratory of Nanotechnology and Materials Technologies of the Institute of Engineering Materials and Biomaterials. Changes in the microstructure after individual stages of hot plastic deformation were determined on the basis of detailed microstructure tests with the light microscope and scanning electron microscope. An X-ray phase qualitative analysis of the examined materials in the condition after casting and after thermoplastic working was carried out with the XPert diffractometer by Philips. Findings: It was concluded based on the tests performed that the structure of the examined austenitic high-manganese steel in the initial condition is represented by austenite with numerous annealing twins. The results obtained for investigations in a continuous compression test will enable to establish power and energy parameters and design a hot compression process, consisting of several phases, of axisymmetric specimens, simulating the final rolling passes. Practical implications: By elaborating the detailed data concerning structural changes and power and energy parameters of the thermoplastic working process of the investigated high-manganese austenitic TWIP steel type, it will be possible to design appropriately the final passes of the hot rolling process to obtain an optimum size of grains, which will in turn influence the improved strength properties of the investigated high-manganese austenitic X11MnSiAl25-1-3 steel. Originality/value: The application of thermoplastic working of high-manganese austenitic TWIP steel.

4

Thermo-mechanical processing of high-manganese austenitic TWIP-type steels

Grajcar A., Borek W.

Archives of Civil and Mechanical Engineering

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2008

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Vol. 8, no 4

29-38

EN

The high-manganese austenitic steels are an answer for new demands of automotive industry conceming the safety of passengers by the use of materials absorbing high values of energy during collisions. The chemical compositions of two high-manganese austenitic steels containing various Al and Si concentrations were developed. Additionally, the steels were microalloyed by Nb and Ti in order to control the grain growth under hot-working conditions. The influence of hot-working conditions on recrystallization behaviour was investigated. On the basis of initial investigations realized by hot upsetting the thermo-mechanical conditions resulting in a fine-grained structure were designed. The [...] curves and identification of thermally activated processes controlling work-hardening by the use of the Gleeble simulator were determined. It was found that the thermo-mechanical treatment conditions influence a phase composition of the investigated steels after solution heat treatmenl.

PL

Wysokomanganowe stale austenityczne stanowią odpowiedź dla nowych żądań przemysłu motoryzacyjnego dotyczących bezpieczeństwa pasażerów przez zastosowanie materiałów absorbujących dużą ilość energii w warunkach kolizji. Opracowano składy chemiczne dwóch wysokomanganowych stali austenitycznych zawierających różne stężenie Al i Si. Dodatkowo, w celu kontroli rozrostu ziaren w warunkach obróbki plastycznej na gorąco stale zawierają mikrododatki Nb i Ti. Zbadano wpływ warunków obróbki plastycznej na gorąco na przebieg rekrystalizacji. Na podstawie badań wstępnych zrealizowanych przez spęczanie na gorąco zaprojektowano warunki obróbki cieplno-mechanicznej prowadzące do uzyskania drobnoziarnistej struktury. Przy zastosowaniu symulatora Gleeble wyznaczono krzywe [...] oraz aktywowane cieplnie procesy kontrolujące umocnienie odkształceniowe. Stwierdzono, że warunki obróbki cieplno-mechanicznej mają wpływ na skład fazowy badanych stali po przesycaniu.