Control of Microstructure during the Eutectoid Transformation in the As-cast Spheroidal Graphite Cast Iron with »in-situ« Dilatation Analysis and Quenching Experiments

2006 ◽  
Vol 77 (5) ◽  
pp. 361-369 ◽  
Author(s):  
Primož Mrvar ◽  
Jožef Medved ◽  
Alojz Križman
Keyword(s):  
Cast Iron ◽  
Spheroidal Graphite ◽  
Eutectoid Transformation ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

Influence of Cooling Rate and Alloying Elements on Kinetics of Eutectoid Transformation in Spheroidal Graphite Cast Iron

2010 ◽  
Vol 457 ◽  
pp. 163-168 ◽  
Author(s):  
Primož Mrvar ◽  
Mitja Petrič ◽  
Jožef Medved
Keyword(s):  
Cast Iron ◽  
Cooling Rate ◽  
Alloying Elements ◽  
Spheroidal Graphite ◽  
Eutectoid Transformation ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Short Time ◽  
Kinetics Of

Paper deals with influence of cooling rate and alloying elements on kinetics of eutectoid transformation in spheroidal graphite cast iron (SGI). Transformation of austenite can proceed into ferrite and graphite (FeFeG) and/or in pearlite (Fe  FeFe3C). Examination of eutectoid transformation was made by evaluating the “in-situ” dilatation curves together with metallographic examinations, DTA, and dilatation analyses in solid state. ThermoCalc software was applied for thermodynamic calculations of phase equilibria. Based on numerous quantitative relations, such as relation between fractions of ferrite and pearlite in the as-cast SGI that was determined by analysis of dilatometric curves and taking into account also composition of melt, ferrite/pearlite ratio in the microstructure could be determined in a very short time. Thus the melt composition could be corrected by adding Cu and/or Mn or Si, respectively, using the "in situ" dilatation analyses. Characteristic temperatures of eutectoid transformation have been established from the kinetics of austenite transformation and from temperature dependence of ferrite and/or pearlite growth. Kinetics curves that enable to determine fractions of single microstructure constituents in the microstructure as function of transformation time, mainly used for ferrite and pearlite SGI, can be well determined with physical sigmoidal Boltzmann model.

Study of the Eutectoid Transformation in the As-Cast Spheroidal Graphite Cast Iron with 'in Situ' Dilatation Analysis – Method for Quality Control

2006 ◽  
Vol 508 ◽  
pp. 287-294 ◽  
Author(s):  
Primož Mrvar ◽  
Milan Tribžan ◽  
Jožef Medved ◽  
Alojz Križman
Keyword(s):  
Cast Iron ◽  
Spheroidal Graphite ◽  
Eutectoid Transformation ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Transformation Time ◽  
Short Time ◽  
Boltzmann Model ◽  
Ferrite Nucleation

The eutectoid transformation of the spheroidal graphite cast iron (S.G.I.) has been investigated with “in situ” dilatometer, which was made for the investigation of the cast iron alloys. The investigation of the eutectoid transformation has been taking place by evaluation of the “insitu” dilatation curves in connection with metallographic examinations, chemical analyses and thermodynamic calculations of the phase equilibriums. By dilatometric curves it is possible to follow the exact eutectoid transformation of austenite. On a basis of numerous quantitative relations, as the relation between the ferrite and pearlite fractions in the as-cast SGI, which was determined by the analysis of the dilatometric curves and the composition, the ratio between ferrite and pearlite in the microstructure could be determined in a very short time. From the kinetics of austenite transformation and temperature dependence of the ferrite or pearlite growth the following characteristic temperatures of the eutectoid transformation have been established: the ferrite nucleation o Tα , the beginning of the ferrite growth Tα , and pearlite growth Tp , respectively. Kinetic curves, which show the fraction of the single microstructure constituents in the microstructure in dependence of the transformation time for mainly ferrite SGI, are good represented by the physical sigmoidal Boltzmann model.

The role of manganese and copper in the eutectoid transformation of spheroidal graphite cast iron

1997 ◽  
Vol 28 (10) ◽  
pp. 2015-2025 ◽  
Author(s):  
Aline Boudot ◽  
Valérie Gerval ◽  
Djar Oquab ◽  
Jacques Lacaze ◽  
Henrique Santos
Keyword(s):  
Cast Iron ◽  
Spheroidal Graphite ◽  
Eutectoid Transformation ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron

Color Etching for Characterization the Grain Orientation in Spheroidal Graphite Cast Iron

2007 ◽  
Vol 537-538 ◽  
pp. 389-396 ◽  
Author(s):  
Ibolya Kardos ◽  
Zoltán Gácsi ◽  
Péter János Szabó
Keyword(s):  
Cast Iron ◽  
Crystallographic Orientation ◽  
Grain Orientation ◽  
Test Material ◽  
Spheroidal Graphite ◽  
Metallic Materials ◽  
Additional Information ◽  
Spheroidal Graphite Cast Iron ◽  
Graphite Cast Iron ◽  
Back Scattering

Color etching is a widely used technique for visualizing different phases in metallic materials. Its advantage to the traditional etching techniques is that it gives additional information within one phase, namely, the color shade of a given phase can change in a certain range. This paper demonstrates that, due to the physics of the color etching, the shade of a phase also depends on the crystallographic orientation of the investigated grain. As a test material, spheroidal graphite cast iron was used, and individual grain orientation was identified by automated electron back scattering diffraction (EBSD). Results showed that there is a strong correlation between grain orientation and the shades obtained by color etching.

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