Influence of carbon content on the segregation processes in duplex cast steel

• Autorzy: Stradomski Z. , Dyja D.
• Języki publikacji: EN

Abstrakty

EN

The paper aimed at determination of increased carbon content influence on segregation processes in a duplex ferritic-austenitic cast steel. The analysis of raw cast steel structure was carried out using a Zeiss Axiovert 25 optical microscope. The chemical composition of selected areas was examined using a JEOL JSM 5400 scanning microscope equipped with an EDX microanalyser and the obtained results were verified using the Thermo-Calc software. The investigations carried out have shown that the lower carbon content causes the smaller amount of the intermetallic phases precipitates undesirable in the manufacturing process, which – affecting a clear deterioration in raw cast steel impact strength – promote origination of cracks in the castings. The increased, due to segregation processes, content of carbon, chromium and molybdenum within the solidification grain boundaries promotes precipitation of carbides already in the liquid state, what increases the propensity for hot cracking. The molybdenum content, in a cast steel of increased carbon content, varies from ~4% in the centre of solidification grain to ~6.5% in its boundary areas, and the chromium content from ~28% to 32%, respectively. Small enrichment of ferrite with molybdenum and chromium in boundary areas of cast steel solidification grains containing 0.02% carbon causes higher ferrite stability and prevents its decomposition in the temperature range from 600 to 900°C, what makes that the cast steel of lower carbon content features uniform ferritic-austenitic structure in as cast state.

Słowa kluczowe

EN

casting defect; segregation; sigma phase; carbides; duplex cast steel

PL

wady odlewów; faza sigma; węgliki; staliwo typu duplex

• Wydawca: Komisja Odlewnictwa Polskiej Akademii Nauk Oddział w Katowicach
• Czasopismo: Archives of Foundry Engineering
• Rocznik: 2007
• Tom: Vol. 7, iss. 1
• Strony: 139--142
• Opis fizyczny: Bibliogr. 15 poz., rys., tab.

Twórcy

autor

Stradomski Z.

autor

Dyja D.

• Institute of Materials Engineering; Faculty of Materials Processing Technology and Applied Physics; Czestochowa University of Technology; Al. Krajowej 19; 42-200 Czestochowa,

Bibliografia

• [1] R. Francis, G. Byrne, G.R. Warburton, Experiences with Zeron 100 superduplex stainless steel in the process industries, 5th World Duplex Conference & Exhibition - DSS 99, Rome, 613-623
• [2] Ping Li, Qizhou Cai, Bokang Wei, Failure analysis of the impeller of slurry pump used in zinc hydrometallurgy process, Engineering Failure Analysis, Vol. 13 (2006) 876-885
• [3] C. Shargay, Application of duplex stainless steels in refining, Stainless Steel World, Vol. 12 (2005) 19-27
• [4] D. Dyja, Z. Stradomski, S. Stachura, Possibilities of microstructure steering in ferritic-austenitic cast steel type GX2CrNiMoCu25-6-3-3, Archives of Foundry, Vol. 6, No. 18 (2006) 459-464 (in Polish).
• [5] G. Lothongkum, P. Wongpanya, S. Morito, T. Furuhara, T. Maki, Effect of nitrogen on corrosion behavior of 28Cr-7Ni duplex and microduplex stainless steels in air-saturated 3.5wt% NaCl solution, Corrosion Science 48 (2006) 137-153
• [6] K. A. Bakken, Cost effective materials selections-what is true?, Stainless Steel World 2005 Conference & Expo Maastricht, s.18
• [7] Ededlstahl Aktuell, April 2006
• [8] Stainless Steel News, Vol. 15 (2006) 4-5
• [9] J.C. Tissier, D. Balloy, J. Dairon, S. Dorlencourt, J.-J. Ninin, Vacuum decarburization: a solution within reach of small foundries, Fonderie Fondeur d'Aujourd'hui, Vol. 246 (2005) 28-39
• [10] K. M Lee, H. S. Cho, D. P. Choi, Effect of isothermal treatment of SAF 2205 duplex stainless steel on migration of δ/γ interface boundary and growth of austenite, Journal of Alloys and Compounds,Vol. 285 (1999) 156-161
• [11] T.H. Chen, J.R. Yang, Effects of solution treatment and continuous cooling on σ-phase precipitation in a 2205 duplex stainless steel, Materials Science and Engineering, Vol. A311 (2001) 28-41
• [12] D. Dyja, Z. Stradomski, Solidification model of high alloy Fe-Cr-Ni cast steels, Archives of Foundry, Vol. 6, No. 19 (2006) 81-88 ( in Polish).
• [13] Z. Stradomski, S. Stachura, D. Dyja, Technological problems in elaboration of massive casting from duplex cast steel, SSW 2005 Conference&Expo, Maastricht, Netherlands 2005, p. 363-368.
• [14] Z. Stradomski, S. Stachura, D. Dyja, A. Zyska, Technological problems in elaboration of massive castings from duplex cast steel in aspect of production process optimization, Archives of Foundry, Vol. 5, No. 17 (2005), (in Polish).
• [15] D. Dyja, Z. Stradomski, S. Stachura, Solidification structure of massive castings from duplex cast steel, Archives of Foundry, Vol. 5, No. 15 (2005) 79-86.