The excellent static mechanical properties of solid solution strengthened grades of ferritic ductile iron (SSFDI) are adjusted by elevated silicon contents and undergo a rapid loss above a critical content of about 4.3 wt-% silicon. This phenomenon is attributed to the formation of iron-silicon superstructures that is intensified in particular by the formation of silicon microsegregation. In order to affect silicon microsegregation, the alloying concept of SSFDI has been modified. In the present investigations, an inversion of the silicon microsegregation profile could be achieved by alloying a nodular cast iron melt with 1.2 wt-% aluminium. The results provide a metallurgical tool to shift the silicon embrittlement to higher silicon contents and thus to further enhance the mechanical properties of SSFDI.
Swedish Standard Institute. SS140720 - Spheroidal graphite cast iron. Stockholm: SSI; 1998.
2.
DIN EN 1563: Gießereiwesen – Gusseisen mit Kugelgraphit. 2012.
3.
BjörkegrenL-E.Silicon alloyed ductile iron with excellent ductility and machinability. Hilton Head Island, SC: Keith Millis Symposium on Ductile Cast Iron; 2003.
MikoleizikP, GeierG.SiWind - Werkstoffentwicklung für Offshore-Windenergieanlagen im Multi-Megawatt-Bereich. Giesserei. 2014;9(101):64–69.
6.
WernerH, LappatI, AurichB.Mischkristallverfestigte EN-GJS-Werkstoffe für Groß- und Schwergussteile. Giesserei. 2016;103(2):38–42.
7.
SeidelS.Machbarkeitsstudie zur Herstellung von mischkristallverfetigtem ferritischem Gusseisen mit Kugelgrafit im Großguss Teil 1. Giesserei. 2016;103(07):24–27.
8.
BleicherC, WagenerR.SiWind - neuer Werkstoff für Offshore-Windenergieanlagen Teil 2: Zyklische Werkstoffprüfung. Giesserei. 2014;101(09):70–79.
9.
WeißP, TekavcicA, Bührig-PolaczekA.Mechanistic approach to new design concepts for high silicon ductile iron. Mater Sci Eng. 2018;713:67–74.
10.
HasseS.Niedriglegiertes Gusseiesen mit Kugelgraphit. Giesserei-Praxis. 2005;8:293–301.
11.
SertuchaJ, LacazeJ, SerrallachJ, Effect of alloying on mechanical properties of as cast ferritic nodular cast irons Einfluss des Legierens auf die mechanischen Eigenschaftenvon ferritischem Gusseisen mit Kugelgraphit im Gusszustand [Datenbank: TEMA, Copyright WTI-Frankfurt eG]. Mater Sci Tech. 2012;28(2):184–191.
12.
LekakhSN, RichardsVL, MedvedaN.Effect of Si segregation on low temperature toughness of ductile iron. AFS Trans. 2012;12(31):319–327.
13.
WittigJ, FrommeyerG.Deformation and fracture behavior of rapidly solidified and annealed iron-silicon alloys. Metall Mater Trans A. 2008;39(2):252–265.
14.
WeißP, BrachmannJ, Bührig-PolaczekA, Influence of nickel and cobalt on microstructure of silicon solution strengthened ductile iron. Mater Sci Tech. 2014;31:1479–1485.
15.
WeißP, RiebischM, Bührig-PolaczekA.Mechanical properties and impact toughness of nickel and aluminium alloyed high silicon ductile iron. Int J Metalcast. 2017;12(1):106–112.
16.
DIN E. 50125. DIN-Materialprüfnormen für metallischen Werkstoffe. 2000;1:81–88.
SoińskiMS, JakubusA, StradomskiG.The influence of aluminium on the spheroidization of cast iron assessed on the basis of wedge test. Arch Foundry Eng. 2013;13(2):163–168.
19.
SoińskiMS, JakubusA, SkurkaK.Characteristics of graphite precipitates in aluminium cast iron treated with cerium mixture. Arch Foundry Eng. 2015;15(1):93–98.
JolleyG, GilbertGNJ.Segregation in nodular iron and its influence on mechanical properties. Edinburgh: The British Foundryman; 1967.
23.
LacazeJ.Solidification of spheroidal graphite cast irons: III. microsegregation related effects. Acta Mater. 1999;47(14):3779–3792.
24.
Shayesteh-ZeraatiA, Naser-ZoshkiH, Kiani-RashidAR, The effect of aluminium content on morphology, size, volume fraction,and number of graphite nodules in ductile cast iron. J Mater: Des Appl. 2009;224(1):117–122.
25.
HaghdadiN, BazazB, Erfanian-NaziftoosiHR, Microstructural and mechanical characteristics of Al-alloyed ductile iron upon casting and annealing. Int J Min Met Mater. 2012;19(9):812–820.
26.
MuhmondHM.On the inoculation and graphite morphologies of cast iron [Doctoral Thesis]. Stockholm, Sweden: The Royal Institute of Technology; 2014.
27.
WeißP.Abschlussbericht AiF-Nr. 18554 - Metallurgische Optimierung von hochsiliziumhaltigen mischkristallverfestigtem Gusseisen mit Kugelgraphit hinsichtlich der Sicherstellung der Zähigkeit und Prozessierbarkeit. Foundry-Institute RWTH Aachen; 2017.
