Influence of cast part size on macro- and microsegregation patterns in a high carbon high silicon steel
Basso (a), I. Toda-Caraballo (b), D. San-Martín (b), F.G. Caballero (b),∗
(a) Department of Metallurgy, INTEMA – CONICET, University of Mar del Plata, Av. Juan B Justo 4302, 7600 Mar del Plata, Argentina
(b) MATERALIA Research Group, Department of Physical Metallurgy, Centro Nacional de investigaciones Metalúrgicas (CENIM – CSIC), Av. Gregorio del Amo 8, 28040 Madrid, Spain
In this work, the macro and microsegregation of Cr, Si and Mn have been investigated in a high-carbon high-silicon cast steel using X-ray fluorescence (XRF) and electron probe microanalysis (EPMA), respectively. Two different keel block sizes with leg thicknesses of 12.5 and 75 mm have been compared. In each of the keel blocks, three different locations along the leg thickness have been analyzed: A) zone near surface (≈1 mm); C) the central zone of the leg thickness and B) an equidistant zone from A and C. After comparing the analysis performed by XRF in these three zones no macrosegregation of the Cr, Mn and Si has been observed in any of the two keel blocks. However, clear microsegregation patterns have been obtained by EPMA for these three elements; interdendritic zones are enriched while dendrites are impoverished in these elements implying that their partition coefficient is lower that the unity (k < 1). This coefficient has been estimated using the EPMA measurements and Thermo-Calc calculations, finding good agreement between both approaches for Si and Mn but not for Cr. Finally, for both keel block leg thicknesses, similar microsegregation intensity, measured in ,terms of alloying element concentration has been observed. This result suggests that the cast part size (or dimension) do not have a strong influence on the microsegregation profiles. This it attributed to the back diffusion phenomena involving redistribution of solute during the solidification process.
 Caballero FG, Chao J, Cornide J, García-Mateo C, Santofimia MJ, Capdevila C. Toughness of advanced high strength bainitic steels. Mater Sci Forum 2010;638:118–23,
 Edmonds DV. Advanced bainitic and martensitic steels with carbide-free microstructures containing retained austenite. Mater Sci Forum 2010;638:110–7,
 De Moor E, Speer JG. Chapter 10: bainitic and quenching and partitioning steels. In: Automotive steels. Woodhead Publishing-Elsevier; 2017. p. 289–316,
 Bhadeshia HKDH. Chapter 13: modern bainitic alloys. In: Bainite in steels. Transformations, Microstructure and properties. second edition IOM Communications Ltd; 2001. p. 373–7,
 Caballero FG, Bhadeshia HKDH, Mawella KJA, Jones DG, Brown P. Design of novel high strength bainitic steels: part 1. Mater Sci Technol 2001;17:512–6,
 Caballero FG, Bhadeshia HKDH, Mawella KJA, Jones DG, Brown P. Design of novel high strength bainitic steels: part 2. Mater Sci Technol 2001;17:517–22,
 Caballero FG, Bhadeshia HKDH, Mawella KJA, Jones DG, Brown P. Very strong low temperature bainite. Mater Sci Technol 2001;18:279–84,
 Carmo DJ, Días J, Santos D. High cycle rotating bending fatigue property in high strength casting Steel with carbide free bainite. Mater Sci Technol 2012;28:991–3,
 Yoozbashi M, Wang T. Design of a new nanostructures, high-Si bainitic steel with lower cost production. Materials and design 2011;32:3248–53,
 Fredriksson H, Åkerlind U. chapter 8: crystal growth controlled by heat and mass transport and chapter 11: peritectic solidification structures. In: Solidification and crystallization processing in metals and alloys. first edition Wiley & Sons, Ltd; 2012. p. 433–74,
 Cahn R, Haasen P. chapter 7.3: microsegregation and chapter 9.3: macrosegregation. Physical metallurgy, Vol. 1, 4th edition Elsevierd Ltd. ISBN 978-0-444-89875-3; 1996. p. 749–52, 791-792.
 Gong L, Chen B, Zhang L, Ma Y, Liu K. Effect of cooling rate on microstructure, microsegregation and mechanical properties of cast Ni-based superalloy K417G. J Mater Sci Technol 2018;34:811–20,
 Mao M, Guo H, Wang F, Sun X. Effect of cooling rate on the solidification microstructure and characteristics of primary carbides in H13 steel. Isij Int 2019;59:848–57,
 Shi X, Duang G, Yang W, Guo H, Guo J. Effect of cooling rate on microsegregation during solidification of superalloy INCONEL 718 under slow-cooled conditions. Metall Mater Trans B 2018;49B:1883–97,
 Sourmail T, Caballero FG, Garcia-Mateo C, Smanio V, Ziegler M, Kuntz C, et al. Evaluation of potential of high Si high C steel nanostructured bainite for wear and fatigue applications. Mater Sci Technol 2013;29:1166–73
 Sourmail T, oCLC: 931846023 https://10.2777/958, 2013.
 Garcia-Mateo C, Paul G, Somani M, Porter D, Bracke L, Latz A, et al. Transferring nanoscale bainite concept to lower C contents: a perspective. Metals 2017;7:1–12
 Garcia-Mateo C, Caballero FG, Sourmail T, Cornide J, Smanio V, Elvira R. Composition design of nanocrystalline bainitic steels by diffusionless solid reaction. Met Mater Int 2014;20:405–15
 Timokhina IB, Beladi H, Xiong XY, Adachi Y, Hodgson PD. Nanoscale microstructural characterization of a nanobainitic steel. Acta Mater 2011;59:5511–22,
 Garcia-Mateo C, Caballero FG, Sourmail T, Cornide J, Smanio V, Elvira R. Tensile behaviour of a nanocrystalline bainitic steel containing 3 wt% silicon. Mater Sci Eng A 2012;549:185–92,
 Garbarz B, Burian W. Microstructure and properties of nanoduplex bainite–austenite steel for ultra-high-strength plates. Steel Res Int 2014;85:1620–8,
 Soliman M, Palkowski H. Development of the low temperature bainite. Arch Civ Mech Eng 2016;16:403–12,
 Sourmail T, Caballero FG, Garcia-Mateo C, Morales-Rivas L, Rementeria R, Kuntz M. Tensile ductility of nanostructured bainitic steels: influence of retained austenite stability. Metals 2017;7:31–8,
 Tenaglia N, Boeri R, Massone J, Basso A. Assessment of the austemperability of high-silicon cast steels through Jominy hardenability tests. Mater Sci Technol 2018;34:1990–2000,
 Garcia-Mateo C, Caballero FG, Bhadeshia HKDH. Acceleration of low-temperature bainite. Isij Int 2003;43:1821–5,
 Thermo-Calc Software TCFE Steels/Fe-alloys database version 8 (https://www.thermocalc. com/media/10306/dbd tcfe8 extendedinfo.pdf, access date: 20 February 2019).
 Bramfitt BL, Lawrence SJ. Metallography and microstructures of carbon and Low-alloy steels. Metallography and microstructures, Vol. 9. ASM Handbook, ASM International; 2004. p. 608–26,
 Spanos G, Kral MV. The proeutectoid cementite transformation in steels. Int Mater Rev 2009;54:19–47,
 Guan R-G, Zhao Z-Y, Chao R-Z, Liu X-H, Lee CS. Effects of deformation parameters on formation of pro-eutectoid cementite in hypereutectoid steels. J Cent South Univ 2014;21:1256–63,
 Kozeschnik E, Bhadeshia HKDH. Influence of silicon on cementite precipitation in steels. Mater Sci Technol
 Chang LC. Microstructures and reaction kinetics of bainite transformation in Si-rich steels. Mater Sci Eng A 2004;368:175–82,
 Caballero FG, Miller MK, Babu SS, Garcia-Mateo C. Atomic scale observations of bainite transformation in a high carbon high silicon steel. Acta Mater 2007;55:381–90,
 Han K, Edmonds DV, Smith GDW. Optimization of mechanical properties of high-carbon pearlitic steels with Si and V additions. Metall Mater Trans A 2001;32A:1313–24,
 Kim B, Boucard E, Sourmail T, San Martin D, Gey N, Rivera-Diaz-del-Castillo PEJ. The influence of silicon in tempered martensite: Understanding the microstructure–properties relationship in 0.5–0.6 wt.% C steels. Acta Mater 2014;18:169–78,
 Petty ER. Physical metallurgy of engineering materials. London: George Allen and Unwin Ltd; 1970.
 Ando T, Krauss G. The isothermal thickening of cementite allotriomorphs in a 1.5Cr-1C steel. Acta Metall 1981;29:351–63,
 Heckel RW, Paxton HW. Rates of growth of cementite in hypereutectoid steels. Trans Metall Soc AIME 1960;218:799–806.
 Krauss G. The microstructure and fracture of a carburized steel. Metall Trans A 1978;9:1527–35,
 Krauss G. The relationship of microstructure to fracture morphology and toughness of hardened hypereutectoid steels in case hardened steels: microstructure and residual stress effects. TMS-AIME; 1984. p. 33–56.
 Yan W, Chen W, Li J. Quality control of high carbon steel for steel wires. Materials 2019;12:846–72,
 Porter D, Easterling K. Chapter 4.4.2: segregation in ingots and castings. In: Phase transformation in metals and alloys.
T.J. Press Ltd.; 1981. p. 237–8. ISBN 0-442-30440-4.
 Campbell J. Chapter 5: solidification structure. In: Complete casting handbook. Metal casting processes, metallurgy, techniques and design. T.J. Press Ltd.; 2015. p. 163–222,
http://dx.doi.org/10.1016/B978-0-444-63509-9.00005-4. ISBN 978-0-444-63509-9.
 Fredriksson H. On the solidification of steel ingots and continuously cast steel billets and slabs. Materials Properties and Processing 2013;30:233–44,
 PicIkercing E. Marosegregation in steel ingots: the applicability of modelling and characterization techniques.Isij Int 2013;53:935–49,
 Sang BG, Kang XH, Liu DR, Li DZ. Study on marosegregation in heavy steel ingots. Int J Cast Met Res 2010;23:205–10,
 Metals Handbook Volume 15. “Castings”. Chapter: Cellular and dendritic interfaces. ASM International. 2008. 321-341. Chapter: Defects, 1395, 1523-1525, 1636, 1642.
 [Magmasoft® – Simulation and Virtual Optimization of Casting Processes, version 18.104.22.168,
 Su RJ, Overfelt RA, Jemian WA. Microstructural and compositional transients during accelerated directional solidification of Al-4.5 wt pct Cu. Metall Mater Trans A 1998;29:2375–81,
 Rivera G, Boeri R, Sikora J. Revealing the solidification structure of nodular iron. Int J Cast Met Res 1995;8:1–5,
 Tenaglia N, Boeri R, Basso A, Massone J. Macro and microstructural characterization of high Si cast steels – study of microsegregation patterns. Int J Cast Met Res 2017;30:103–11,
 You D, Bernhard C, Weiser G, Michelic S. Microsegregation model with local equilibrium partition coefficients during solidification of steels. Steel Res 2016;7:840–7,
 Yoshida N, Umezawa O, Nagai K. Influence of phosphorus on solidification structure in continuously cast 0.1 mass% carbon steel. Isij Int 2003;43:348–57,
 Walker P, Kerrigan F, Green M, Cardinal N, Connell J, Rivera-Dı´az-del-Castillo P. Modelling of microsegregation in a 1C-1.5Cr type bearing steel. Adv Steel Technol Roll Bear 2015;12:54–80,
 Yoshida N, Umezawa M, Nagai K. Analysis on refinement of columnar grain by phosphorus in continuously cast 0.1 mass% carbon steel. Isij Int 2004;44:547–55,
 Omar M, Atklnson H, Palmlere E, Howe A, Kapranos P. Microstructural Development of HP9/4/30 steel during partial remelting. Steel Res Int 2004;75:552–60,
 Lacaze J, Benigni P, Howe A. Some issues concerning experiments and models for alloy microsegregation. Adv Eng Mater 2003;5:37–46,
 Hillert M, Hoglund L, Schalin M. Role of back-diffusion studied by computer simulation. Metall Mater Trans A 1999;30:1635–41, http://dx.doi.org/10.1007/s11661-999-0100-2.
 Dobrovská J, Francová H, Kavicka F, Dobrovská V. Investigation of influence of cooling rate on back diffusion at solidification of continuously cast steel billet. Metal 2010;2010:1–8.
 Turkeli A, Kirkwood D. Back diffusion of manganese during solidification of carbon steels. Mater Sci Forum 2006;508:443–8,
 Kozeschnik E, Ozeschnik. A Scheil–Gulliver Model with back diffusion applied to the microsegregation of chromium in Fe-Cr-C alloys. Metall Mater Trans A 2000;31:1682–4,
 Battle T, Pehlke R. Equilibrium partition coefficients in Iron-Based alloys. Metall Trans B 1989;20:149–60,
 Celada C, Toda-Caraballo I, Kim B, San Martín D. Chemical banding revealed by chemical etching in a cold-rolled metastable stainless steel. Mater Charact 2013;8:142–52,