7/25/2019 SOLIDIFICATION CONTROL BY THERMAL ANALYSIS OF La-INOCULATED GREY CAST IRON

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SOLIDIFICATION CONTROL BY THERMAL ANALYSIS OF La-INOCULATED

GREY CAST IRON

E. M. Stefan*, M. Chisamera

Politehnica University of Bucharest, 313 Spl. Independentei, RO-000!", Bucharest,Ro#ania$

e#ail% stefan&eduard"000'yahoo.co#

Keywords: thermal analysis, cooling curve, castings, grey cast iron, La,Bainoculation, chill tendency, graphite, microstructure, hardness test

Absra!:  The mastering of internal microstructures play a crucial role inimproving characteristics and properties of cast irons. For this, generally, areused CalFeSi alloys system !hich are added into the gray "ase irons to improvethe properties of the solidi#ed melt. The mechanism of controlling #nalmicrostructure of casting products is still o"$ect of ma$or uncertainty in thescienti#c literatures and has "een, and still is, an su"$ect of intensive research.

 The most common %uestion forall producers of gray ironcastings is ho! they can "esure a"out the %uality of nucleation for o"taining angood product &'(. Thermalanalysis is an important tool totry to ans!er this %uestion &)(.n this research, +.- !t./La,Ba0CalFeSi system alloys!as used to investigate theinoculation e1ect of electricallymelted near0eutectic gray castiron +2.3304.'2 CE/ having

.'5 !t. S. The cooling curveof each sample !as recorded+#g. '/ and computer0aidedanaly6ed "y using a specialsoft!are

to7 a/ esta"lish the particular characteristics of the registered cooling curves, "/emphasi6e the solidi#cation parameters that sho!s more sensi"ility as against Laaddition in treated cast iron and, eventually, c/ to improve thermal analysistechni%ue used for control of La0inoculated gray cast irons. For the assessment of the correctness of the results esta"lished "y thermal analysis !ere performedanother sets of analysis "y other control methods that included chilling tendency,the evaluation of graphite structures using optical microscopy and Brinell

hardness tests.

Fig. '. 0 8ecorded cooling curves patterns of

La,BaCalFeSi inoculated and uninoculatedgray irons and the corresponding e1ects of

treatment over the #nal gray cast ironsmicrostructure.

7/25/2019 SOLIDIFICATION CONTROL BY THERMAL ANALYSIS OF La-INOCULATED GREY CAST IRON

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Se"e!#$e re%ere&!es'. 9.M. Stefanescu 0 (odelin) of *ast Iron Solidi+cationhe e+nin) (o#ents . MetallMater Trans ):; 2<; '42204:, p. '445

). M. Chisamera, . 8iposan, S. Stan, E. Stefan, C. Costache 0 her#al analysiscontrol of in#ould and ladle inoculated )rey cast irons. China Foundry, vol. 5, no.), )3, pp. '4-0'-'