Products

exploded graphite in ductile irons

A Possible Mechanism for the Formation of Exploded Graphite in

Graphite degeneracy such as so-called exploded graphite is then often associated with this flotation phenomenon and it appears as precipitates where the nodular form is replaced by star-like or flower-like shape. It has been reported that exploded graphite develops after the primary spheroidal nodules have reached some tens of microns in diameter.

More

Rating Graphite Structures in DI - Ductile Iron Society

Type IV micular“ver” “compacted” graphite is the predominant form in compacted graphite iron. Type V “degenerate” and Type VI “exploded” graphite forms can occur in ductile iron. Type VII “flake” graphite occurs in gray iron and sometimes on the cast surfaces of ductile iron castings. Methods of Rating Nodularity

More

Graphite flotation in ductile iron castings: definition and

1990-11-01  Carbon float is defined as carbon segregation at the top surfaces of ductile iron castings caused by the buoyancy of graphite particles in liquid iron. Flotation of hypereutectic nodules occurs in ductile irons having carbon equivalents greater than 4.5 as defined by the expression CE = C% + (Si% / 3) + (P% / 3).

More

Effect of Antimony on Graphite Growth in Ductile Iron SpringerLink

2020-02-25  During solidification of mostly thick-walled ductile iron castings, the graphite has a tendency to degenerate during eutectic growth, which results in exploded or even chunky graphite. Possible reasons are long solidification times, high amounts of Si and the presence of Ce in the melt. 1

More

Elimination of Chunky Graphite in Castings with Large Thermal

Keywords: Ductile iron, Chunky graphite, Cooling rate, Casting, Thermal point 1. Introduction Disintegrated and exploded graphite may be present in the casts from the above-eutectic cast iron, in particular if CE > 4,5%, or in very slowly cooled cross-sections, where spheres of the graphite float and are disintegrated. The degraded form of the graphite – chunky graphite –

More

(PDF) Graphite Structures in Cast Irons - ELKEM Uğur Özdemir -

NODULARISERS Description of a structure should follow the convention Form : Distribution : Size, e.g. Type IA4 for a grey cast iron Type VI5 for a ductile iron Elkem manufactures and markets a range of high quality nodularising alloys to produce ductile and compacted graphite cast irons. They contain balanced ratios of the active elements to control reactivity, minimise

More

A Review of Common Metallurgical Defects in Ductile Cast Iron

Exploded graphite is normally found in thicker section castings with slow cooling rates or at very high carbon equivalent levels. Figure 6: Sample with exploded graphite present due to excess concentration of rare earth metals. Care should be taken when using induction melting as rare earths can be cumulative in the iron.

More

Metallographic Procedures for Cast Irons - Vacaero

2015-06-10  Manufacture of ductile iron is challenging and at times the degree of nodularity can be lower than desired. Figure 16 shows an example of “exploded” graphite nodules, an undesirable condition. Ductile iron can also be austenitized and isothermally transformed producing austempered ductile iron, Figure 17.

More

Common metallurgical defects in ductile cast iron by Sandeep -

2017-01-07  In excess, however, rare earths can cause exploded graphite. This is more especially when high purity charges are used which are low in tramp elements. Exploded graphite is normally found in...

More

Degenerated Graphite Growth in Ductile Iron Scientific.Net

In the thermal centre of the Pb containing sample graphite spheroids as well as intergranular lamellar graphite have been found. At the same location of the casting containing both Pb and Ce, exploded as well as chunky graphite could be observed, while the formation of intergranular lamellar graphite has been suppressed.

More

Degenerated Graphite Growth in Ductile Iron

Degenerated Graphite Growth in Ductile Iron Babette Ton n 1,a*, ... Several trace elements present in spheroidal graphite cast irons, either intentionally added or resulting from the charges, are known to affect graphite shape. As examples, elements like Pb, Sb or Bi promote formation of intergranular lamellar graphite [1,2]. By addition of Ce to such melts lamellar graphite can be prevented ...

More

Analysis of machinability in ductile iron casting ...

2020-01-01  Spheroidal graphite (SG/DI) iron is also known as nodular iron or ductile iron (DI). SG iron is obtained from grey iron by Mg treatment and inoculation. SG iron consists good mechanical properties as compared to grey iron. DI has excellent castability, superior damping capacity and good combination of strength, ductility and toughness.

More

Graphite Nodule - an overview ScienceDirect Topics

One graphite can be detected in the alloyed layer due to the forces in the molten pool when the powders and substrate are irradiated by the laser. In the nodular iron, graphite nodules gradually dissolved in the molten pool and, at the same time, due to hydrodynamic

More

GRAPHITE STRUCTURES IN CAST IRONS

Elkem manufactures and markets a range of high quality nodularising alloys to produce ductile and compacted graphite cast irons. They contain balanced ratios of the active elements to control reactivity, minimise slag and neutralise tramp elements. Product Active Elements Advantages and Uses

More

HOT TOPICS - Ductile Iron Society

Compacted Graphite % Figure 2 Exploded graphite in over -treated iron. 4) Magnesiu m Requirements Magnesium will react with oxygen and sulfur before it becomes available to spheroidize the graphite phase. The Mg consumed to make oxides and sulfides will

More

A Review of Common Metallurgical Defects in Ductile Cast Iron

Exploded graphite is normally found in thicker section castings with slow cooling rates or at very high carbon equivalent levels. Figure 6: Sample with exploded graphite present due to excess concentration of rare earth metals. Care should be taken when using induction melting

More

Ductile iron - Wikipedia

Ductile iron, also known as ductile cast iron, nodular cast iron, spheroidal graphite iron, spheroidal graphite cast iron and SG iron, is a type of graphite-rich cast iron discovered in 1943 by Keith Millis. While most varieties of cast iron are weak in tension and brittle, ductile iron has much more impact and fatigue resistance, due to its nodular graphite inclusions.

More

Vermicular Graphite Cast Iron :: Total Materia Article

In vermicular graphite cast irons (VG irons), graphite is present in a worm-like, stubby form with rounded edges. This material is also popularly known as compacted graphite cast iron or as CG iron. Vermicular graphite cast iron was an accidental discovery during tonnage production of SG iron castings, and was initially considered a degraded form of iron. Subsequently, it has attracted much ...

More

Iron Types (page 1), Gray Ductile Irons - Metal Casting ...

The unique step in the processing of ductile iron is the nodularization of graphite. This is the step where magnesium is added to the molten alloy to create a residule Mg level of approximately 0.03-0.06%, which is the amount necessary to cause graphite to form spheroids.

More

Degenerated Graphite Growth in Ductile Iron

In the thermal centre of the Pb containing sample graphite spheroids as well as intergranular lamellar graphite have been found. At the same location of the casting containing both Pb and Ce, exploded as well as chunky graphite could be observed, while the formation of intergranular lamellar graphite has been suppressed.

More

Graphite Nodule - an overview ScienceDirect Topics

One graphite can be detected in the alloyed layer due to the forces in the molten pool when the powders and substrate are irradiated by the laser. In the nodular iron, graphite nodules gradually dissolved in the molten pool and, at the same time, due to hydrodynamic

More

HOT TOPICS - Ductile Iron Society

Compacted Graphite % Figure 2 Exploded graphite in over -treated iron. 4) Magnesiu m Requirements Magnesium will react with oxygen and sulfur before it becomes available to spheroidize the graphite phase. The Mg consumed to make oxides and sulfides will

More

The New Methods of Graphite Nodules Detection in Ductile ...

The properties of nodular ductile cast iron are strongly influenced by morphology, size and distribution of graphite particles. Nodular ductile irons have spheroidal graphites in the as-cast state. In this work, these nodules are characterized by means of light optical microscopy (LOM) and electron microscopy (EM). Experimental data are represented by LOM. Metallography is processed to obtain ...

More

On the spheroidal graphite growth and the austenite ...

SOLIDIFICATION IN DUCTILE IRONS by JINGJING QING A DISSERTATION Presented to the Faculty of the Graduate School of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in MATERIALS SCIENCE ENGINEERING 2016 Approved Von L. Richards, Advisor David C. Van Aken Simon N. Lekakh F.

More

Ductile iron - Wikipedia

In ductile irons, graphite is in the form of nodules rather than flakes as in grey iron. Whereas sharp graphite flakes create stress concentration points within the metal matrix, rounded nodules inhibit the creation of cracks, thus providing the enhanced ductility that gives the alloy its name.

More

CHARACTERIZATION OF DUCTILE IRON THROUGH FRACTOGRAPHIC STUDY

Spheroidal graphite iron is also known as nodular iron or ductile iron. This is obtained by making small ladle additions of a modifier such as magnesium or cerium to liquid metal. Unlike flaky graphite in grey cast iron, Spheroidal graphite does not weaken the matrix considerably.

More

Study of microstructure of thick wall ductile iron castings

Abstract : Ductile Iron castings with section thickness 60mm, 70mm 80mm were produced using manufacturing process in which the chemical composition was adjusted to guarantee the formation of spheroidal graphite during solidification. Simultaneously other parameters like carbon equivalent, tapping temperature, inoculation and magnesium residuals were monitored. Microstructure and its ...

More

Induction hardening of cast irons Thermal Processing ...

2018-07-15  The graphite particles appear in cast irons in different forms ranging from flakes and clumps to spheroids. Gray, ductile (nodular), and, to a lesser extent, the malleable and compacted graphite irons are four groups of cast irons that more frequently undergo induction hardening.

More

graphite floatation in ductile irons

Graphite Flotation In Ductile Iron Castings Exploded Graphite In Ductile Irons. Graphite flotation in ductile iron castings definition flotation of hypereutectic nodules occurs in ductile irons having carbon equivalents greater than as defined. Chat Online; Dross Defects In Spheroidal Graphite Cast Iron Castings.

More

Degenerated Graphite Growth in Ductile Iron

Degenerated Graphite Growth in Ductile Iron Babette Ton n 1,a*, ... Several trace elements present in spheroidal graphite cast irons, either intentionally added or resulting from the charges, are known to affect graphite shape. As examples, elements like Pb, Sb or Bi promote formation of intergranular lamellar graphite [1,2]. By addition of Ce to such melts lamellar graphite can

More

The New Methods of Graphite Nodules Detection in Ductile ...

The properties of nodular ductile cast iron are strongly influenced by morphology, size and distribution of graphite particles. Nodular ductile irons have spheroidal graphites in the as-cast state. In this work, these nodules are characterized by means of light optical microscopy (LOM) and electron microscopy (EM). Experimental data are represented by LOM. Metallography is

More

Ductile iron - Wikipedia

Ductile iron, also known as ductile cast iron, nodular cast iron, spheroidal graphite iron, spheroidal graphite cast iron and SG iron, is a type of graphite-rich cast iron discovered in 1943 by Keith Millis. While most varieties of cast iron are weak in tension and brittle, ductile iron has much more impact and fatigue resistance, due to its nodular graphite inclusions.

More

Thermal Analysis of Ductile Iron Casting IntechOpen

2017-04-10  This effect is readily observed in ferrite-pearlite structures of ductile cast irons. The graphite nodule count and its size distribution are important in deciding the quality of the DI castings. The sufficient number of graphite nodules is required in order to avoid formation of carbides during solidification, especially in thin-walled castings because of the high

More

CHARACTERIZATION OF DUCTILE IRON THROUGH FRACTOGRAPHIC STUDY

1.2.History of Ductile Iron 1.3.Grades of SG Irons 1.4.Chemical Composition 1.5.Microstructure 1.6.Family of Ductile Iron 1.7.Production of Ductile Iron 1.8.Properties of Ductile Iron 1.9.Heat Treatment 1.10. Applications. Chapter1: introduction 2 1.1. Introduction Spheroidal graphite iron is also known as nodular iron or ductile iron. This is obtained by making small ladle additions

More

Compacted Graphite Iron Castings - Durham Foundry

Compacted Graphite Iron, which is also known as CGI or Vermicular Graphite Iron, is a form of cast iron in which the shape of the graphite particles is between that of conventional grey iron flakes and ductile iron where the graphite is in spheres. The worm-like compacted-graphite shape provides physical properties that mirror the most beneficial properties of grey and ductile irons.

More

Study of microstructure of thick wall ductile iron castings

Abstract : Ductile Iron castings with section thickness 60mm, 70mm 80mm were produced using manufacturing process in which the chemical composition was adjusted to guarantee the formation of spheroidal graphite during solidification. Simultaneously other parameters like carbon equivalent, tapping temperature, inoculation and magnesium residuals were monitored.

More

Ductile Irons Alloying: Understanding the Basics ...

It begins with an overview of ductile or spheroidal-graphite iron, describing the specifications, applications, and compositions. It then discusses the importance of composition control and explains how various alloying elements affect the properties, behaviors, and processing characteristics of ductile iron. The article describes the benefits of nickel and silicon additions

More

Cast irons Types And Application

Due to graphite flakes, gray cast irons are weak and brittle. However they possess good damping properties,and thus typical applications include: base structures, bed for heavy machines, etc. they also show high resistance to wear. 2) White cast iron: When Si content is low (less than 1%) in combination with faster cooling rates, there is no time left for cementite to get

More

graphite floatation in ductile irons

Exploded Graphite In Ductile Irons. Graphite flotation in ductile iron castings definition flotation of hypereutectic nodules occurs in ductile irons having carbon equivalents greater than as defined. Chat Online; Dross Defects In Spheroidal Graphite Cast Iron Castings . The main and most known defects in spheroidal graphite cast iron castings are the graphite flotation, the

More