The influence of thermo-mechanical processing on deformability and structural changes of duplex steel

• Autorzy: Radwański K. , Niewielski G. , Kuc D.
• Konferencja: 12th International Scientific Conference CAM3S'2006, 27-30th November 2006, Gliwice-Zakopane
• Języki publikacji: EN

Abstrakty

EN

Purpose: In conventional hot deformation methods of duplex steels, low values of boundary strain are obtained, resulting from the disparate behaviour of ferrite and austenite. This paper analyses the capacity for enhancing deformability of two-phase ferritic-austenitic steels of the "duplex" type via thermo mechanical processing. Design/methodology/approach: Steel specimens were subjected to cold deformation with a 70% rolling reduction. After a hot solution treatment beginning at 1350 degrees centigrade, the specimens were tensioned in the "Instron" strength-testing machine in temperatures ranging from 800 to 950 degrees centigrade at a rate of vr=15x10-3/3x10-1 mm/s in a 0.005 Pa vacuum. Structural examination was carried out using light and electron microscopy. A quantitative analysis of structural changes was performed using the "MetIIo" image analysis programme. Findings: The process parameters at which the investigated steel shows the superplastic flow effect have been determined. Practical implications: The capacity for increased deformability through combined thermo-mechanical processes, requiring a precise selection of the deformation parameters, has been indicated. Originality/value: The results obtained are vital for designing an effective thermo-mechanical processing technology for the investigated steel.

Słowa kluczowe

EN

superplastic materials; plastic forming; microstructure; hot tensile test

PL

materiały nadplastyczne; formowanie plastyczne; obróbka plastyczna; mikrostruktura; próba rozciągania na gorąco

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2007
• Tom: Vol. 20, nr 1-2
• Strony: 175--178
• Opis fizyczny: Bibliogr. 15 poz., rys., tab.

Twórcy

autor

Radwański K.

autor

Niewielski G.

autor

Kuc D.

• Silesian University of Technology, Faculty of Materials Science and Metallurgy, ul. Krasińskiego 8, Katowice, 40-019, Poland,

Bibliografia

• [1] S.S.M. Tavares, M.R. da Silva, J.M. Pardal, H.F.G. Abreu, A.M. Gomes, Microstructural changes produced by plastic deformation in the UNS S31803 duplex stainless steel, Journal of Materials Processing Technology 180 (2006) 318-322.
• [2] A. Itman Filho, J.M.D.A. Rollo, R.V. Silva, G. Мartinez, Alternative process to manufacture austenitic-ferritic stainless steel wires, Materials Letters 59 (2005) 1192-1194.
• [3] J.M. Cabrera, A. Mateo, L. Llanes, J.M. Prado, M. Аnglada, Hot deformation of duplex stainless steels, Journal of Materials Processing Technology 143-144 (2003) 321 – 325.
• [4] K. Osada, Commercial applications of superplastic forming, Journal of Materials Processing Technology 68 (1997) 241-245.
• [5] D.C.J. Farrugia, Prediction and avoidance of high temperature damage in long product hot rolling, Journal of Materials Processing Technology 177 (2006) 486-492.
• [6] H. Miyamoto, T. Mimaki, S. Hashimoto, Cyclic deformation of ferritic stainless steel single crystals showing the stress asymmetry, Materials Science and Engineering A319-321 (2001) 779-783.
• [7] B. Zhang, D.J. Mynors, A. Mugarra, K. Ostolaza, Representing the superplasticity of Inconel 718, Journal of Materials Processing Technology 153-154 (2004) 694-698.
• [8] M. Sagradi, D. Pulino-Sagradi, R. E. Medrano, The effect of the microstructure on the superplasticity of a duplex stainless steel, Acta Materialia 46 (1998) 3857-3862.
• [9] H.L.Xing, C.W.Wang, K.F.Zhang Z.R. Wang, Recent development in the mechanics of superplasticity and its applications, Journal of Materials Processing Technology 151 (2004) 196-202.
• [10] Wu Shichun, Li Miaoquan , Du Zhixiao, Liu Mabao, Measurements of the changes in microstructure during superplastic deformation, Journal of Materials Рrocessing Technology 69, 1-3, 1997 203-207.
• [11] J. Szala, J. Cwajna, Image analysis of polycrystalline materials microstructure, Acta Stereologica 18 (1999) 89-94.
• [12] J. Szala, J. Richter, Methods of the shading correction in the two-phase materials structure images, Proceedings of International Conference on Quantitative Description of Materials Microstructure, Warsaw, 1997, 137-146.
• [13] J.D. Bressan B. Baudelet, Prediction of strain rate sensitivity variations in the deformation of superplastic materials, Journal of Materials Processing Technology 32 (1992) 317-323.
• [14] J. Barcik, Process sigma phase in chromium-nickel austenitic steels, Silesian University, Katowice, 1979, (in Polish).
• [15] Zh.L. Jiang, X.Y. Chen, H. Huang, X.Y. Liu, Grain refinement of Cr25Ni5Mo1..5 duplex stainless steel by heat treatment, Materials Science and Engineering A363 (2003) 263-267.