Hot-working behaviour of high-manganese austenitic steels

• Autorzy: Dobrzański L. A. , Grajcar A. , Borek W.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The work consisted in investigation of newly elaborated high-manganese austenitic steels with Nb and Ti microadditions in variable conditions of hot-working. Design/methodology/approach: Determination of processes controlling strain hardening was carried out in continuous compression test using Gleeble 3800 thermo-mechanical simulator. Findings: It was found that they have austenite microstructure with numerous annealing twins in the initial state. Continuous compression tests realized in the temperature range from 850 to 1050*C with the strain rate of 10s ^-1 enabled determination of yield stress values and values of εmax deformations-corresponding to maximum flow stress. It was found that initiation of dynamic recrystallization requires true strain equal at least 0.29. Holding of steel after plastic deformation allowed determining the progress of recrystallization in the function of isothermal holding time. Determined half-times of recrystallization at 900oC after deformation with 25% of reduction are equal 32 and 17s for 27Mn-4Si-2Al-Nb-Ti and 26Mn-3Si-3Al-Nb-Ti steel, respectively. Several-stage compression tests with true strain of 0.29 permit to use dynamic recrystallization for shaping fine-grained microstructure of steel in the whole range of deformation temperature. Decreasing true strain to 0.23 limits the course of dynamic recrystallization to two first deformation cycles. In two final cycles of deformation, as well as in the whole range of hot-working realized with true strain of 0.19-dynamic recovery is the process controlling strain hardening. Practical implications: The obtained microstructure-hot-working conditions relationships and stress-strain curves can be useful in determination of power-force parameters of hot-rolling for sheets with fine-grained austenitic structures. Originality/value: The hot-working behaviour and microstructure evolution in various conditions of plastic deformation for new-developed high-manganese austenitic steels with Nb and Ti microadditions were investigated.

Słowa kluczowe

EN

high-manganese steel; hot-working; TWIP effect; dynamic recrystallization; static recrystallization

PL

obróbka plastyczna na gorąco; rekrystalizacja dynamiczna; rekrystalizacja statyczna; stal manganowa

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2008
• Tom: Vol. 31, nr 1
• Strony: 7--14
• Opis fizyczny: Bibliogr. 16 poz., il., tab., wykr.

Twórcy

autor

Dobrzański L. A.

autor

Grajcar A.

autor

Borek W.

• Division of Materials Processing Technology, Management and Computer Techniques in Materials Science, Institute of Engineering Materials and Biomaterials, Silesian University of Technology, ul. Konarskiego 18a, 44-100 Gliwice, Poland,

Bibliografia

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