Carbon Steel vs Ductile iron-Compositions: Carbon content in carbon steel (<2%) is less than that of ductile iron (>3%). Also, the carbon in ductile iron is in graphite form. Ductile Iron vs Carbon Steel-Castability and Welding Characteristics: Carbon steel provides better weldability than ductile irons. However, Ductile iron has better ...

Hypoeutectic irons solidify to dendrites of austenite in an austenite/graphite eutectic, and hypereutectic irons form primary graphite flakes in the same austenite/graphite eutectic. On further cooling, the austenite decomposes at the eutectoid temperature, at high cooling rates to pearlite and at slow cooling rates to a ferrite–graphite ...

This article discusses the common grades of ductile iron that differ primarily by the matrix structure that contains the spherical graphite. The grades of ductile iron designated by their tensile properties in the specification ASTM A536 are presented in a table.

 — The three presented microstructural highlights on solid-state transformation of graphite, namely secondary graphite formation in ductile cast irons, graphite formation in high silicon medium carbon steels, and void formation during dissolution of graphite, will …

 — It was early suggested that the spheroidal graphite of ductile irons grows predominantly outside of the coupled zone. 3 It has later been proposed that ductile irons do not have a coupled zone; 51 however, this is disputed by observations of chunky graphite in slowly cooled ductile irons, featuring finer graphite morphologies growing coupled ...

58 / Cast Irons Table 1 Comparison of properties of cerium-treated CG iron with FG iron of the same chemical composition, high-strength pearlitic FG iron, and ferrilic SG iron in the as-cast condition

 — Graphite formation in the solid state is both in ductile cast irons and in steels strongly promoted by high silicon contents above 3 wt.% Si. The matrix microstructure in austempered...

It also resists brittle fracture due to its graphite nodules. Production of ductile iron involves adding carbon and other elements like silicon, sulfur, manganese, and magnesium during the smelting process. Magnesium plays a crucial role in forming spherical graphite nodules and reducing sulfur content, which makes the iron and steel more brittle.

 — The use of ductile irons in thermo-mechanically loaded components is increasing, necessitating more knowledge of material properties at intermediate temperatures. A study of the mechanical properties of ductile irons at intermediate temperatures was conducted, investigating the effect of different pearlite fractions along …

The Carbon Equivalent also indicates the risk for graphite flotation and for exploded graphite in ductile iron. ... Figure 2: In hypereutectic irons, the heat released by primary austenite results in a thermal plateau at Point A. Thereafter, the onset of the eutectic solidification of graphite ...

Iron Types (page 1), Gray & Ductile Irons. Home > Iron Types (page 1), Gray & Ductile Irons. Cast Iron Grades. For most modern automotive and consumer applications, cast iron falls into 4 separate categories: ... Doru M., et.al, "The Metallurgy and Tensile Mechanical Properties of Thin Wall Spheroidal Graphite Irons", International Journal ...

 — The evolution of ductile iron with martensitic matrix during annealing at 700 °C was studied in the present study. The results showed that the ultrafine graphite nodules with a count of 8500 nod/mm2 and an average diameter of about 1 µm were obtained in ductile iron through annealing treatment. The martensite in ductile iron was first …

 — Microstructure of gray and ductile irons consists with graphite particles and the iron matrix which can be considered as a composite structure. Therefore, variation of graphite morphology and fraction over the volume of a casting can be considered as an FGM. ... This is known as the graphite flotation commonly occurred in the hypereutectic …

 — 1. Introduction1.1. Chunky graphite. Spheroidal graphite cast iron (SGI), also known as ductile iron exhibits favorable ductility over other cast irons due to nodular graphite precipitations; however, in heavy section ductile iron castings or in whole SGI castings with higher alloying content, graphite degeneration can be observed, which is …

 — Graphite flotation in ductile iron castings by T. N. Blackman, 1988, American Foundrymen's Society edition, in English

effect on the shrinkage tendency of ductile irons. Foundries operating at the higher end of the magnesium range, 0.05% or above, will find that the iron is more prone to shrink than ... Figure 8: Sample with graphite floatation present due to high carbon equivalent. Nodule Alignment Figure 9 shows a classic case of nodule alignment, not too ...

Indeed, the ductile iron foundry, which truthfully claims not to have shrinkage concerns is the exception to the rule. Other common defects may be divided into two basic categories: -Those related to nodule shape and size, such as compacted graphite structures, exploded and chunky graphite, graphite floatation, spiky graphite and nodule alignment.

 — The aim of the present study is to evaluate the actual status of silicon-alloyed ductile cast irons, as recent knowledge on the structure formation, and to review original data obtained by the authors from recent separate publications with additional unpublished data, specifically concerning the structure peculiarities. New data were added to deeply …

 — In the present investigation, mathematical models have been developed to quantify the extent of carbon diffusion occurring in ductile cast iron during cooling from the eutectic temperature. Computer calculations show that small variations in the cooling conditions may significantly alter the number density and size distribution of graphite …

 — Use of rare earths, high silicon and carbon contents, and low cooling rates are reported as possible reasons for formation of chunky graphite in ductile iron castings.

 — The compensation of the contraction in ductile cast irons is provided by graphite precipitation. So, he showed the maximization of graphite precipitation and the minimization of austenite contraction are potentially important process variables. ... Most of these entrainment defects will float up to the top of castings due to the density ...

 — The structure of ductile iron castings usually includes not only spheroidal graphite particles, but also other objectionable deviations from the highest compactness (Table 1), resulting from many different causes 2, 3, 4.Superficial layers on ductile iron castings can include different variants of graphite morphologies, from a mixture of …

 — Part I of this investigation deals with the inoculation mechanisms in ductile cast iron, with particular emphasis on the theoretical aspects of heterogeneous nucleation of graphite at inclusions. It is shown that the majority of the inclusions in ductile cast iron are primary or secondary products of the magnesium treatment(e.g., MgS, CaS, …

Ductile cast irons are materials having strength, impact toughness and ductility comparable to those of many grades of steel while exceeding by far those of standard gray irons. ... Graphite floatation This is caused when …

 — A study of the occurrence of graphite flotation as a function of carbon content in a ductile iron of base composition 2.50%Si, 0.16%Mn, 0.20%Mo, 0.50%Cu and the effect of its presence on the mechanical …

 — Carbon flotation in ductile iron is caused when the foundry allows the Carbon Equilivant to exceed the ability of the magnesium to suppress graphite formation in the liquid. My experience suggests that limit is about 4.55 - 4.60 with moderate levels of magnesium 0.030 to 0.035%.

 — Ductile cast irons (DCIs) are of increasing importance in the renewable energy and transportation sectors. The distribution and morphology of the graphite …

 — graphite in ductile cast irons, Proceedings of the "Keith Millis symposium", Nashville, 2013, AFS, ... This is also consistent with degenerated graphite found in flotation zones in large castings, ...

most striking difference between grey and Ductile Irons. While essential to ... However, as shown in Figure 2c, dross may be associated with graphite floatation, since both graphite and dross have ...

 — 2.1 Melting and Sample Preparation. In this research, experimental ductile iron with a specific chemical composition (as shown in Table 1) was produced using an induction furnace, following the guidelines of ASTM E351 [].The melt was prepared based on ASTM A536 [] for SG40 cast iron, and FeSiMg alloy was introduced into the molten …