Foundry practices critical to the production of cast irons include melting, alloying, molten metal treatment, pouring, and the design of feeding systems (gating and risering) to allow proper filling of the casting mold. This article reviews these production stages of iron foundry casting, with particular emphasis on the melting practices, molten metal treatment, and feeding of molten metal into sand molds. It discusses the castability factors, such as fluidity, shrinkage, and resistance, of gray iron. Typical cupola charge compositions and the final analyses for class 30 and class 40 gray iron castings are presented in a table. The article describes the induction melting and arc furnace melting used in gray iron foundries. It also reviews the inoculation methods such as stream inoculation and mold inoculation, of gray iron.

Unlike gray iron, which contains graphite flakes, ductile iron has an as-cast structure containing graphite particles in the form of small, rounded, spheroidal nodules in a ductile metallic matrix. This article discusses the raw materials that are used for ductile iron production and outlines the most common and important requirements for controlling the composition of ductile iron. Treatment to produce ductile iron involves the addition of magnesium to change the form of the graphite, followed by or combined with inoculation of a silicon-containing material to ensure a graphitic structure with freedom from carbides. The article describes the methods of magnesium treatment, control of magnesium content, and inoculation. It concludes with a discussion on the metallurgical controls of ductile iron production.

This article reviews the production stages of iron foundry casting, with particular emphasis on the melting practices, molten metal treatment, and feeding of molten metal into sand molds. It discusses the molten metal treatments for high-silicon gray, high-nickel ductile, and malleable irons. Foundry practices are also described for compacted graphite, high-silicon ductile, and high-alloy white irons.

This article describes the modification and inoculation of cast iron, and schematically illustrates the major effects of inoculation in gray cast irons. Inoculation could be considered as a common liquid-state treatment for all commercial cast irons (gray/compacted/ductile irons), while modification is essential to produce compacted graphite iron (intermediate level) and ductile iron. The article discusses the most important aspects of a gray cast iron inoculation treatment and the factors influencing its inoculation efficiency. It describes the modification and inoculation of ductile cast iron and compacted graphite cast iron.

Thin-wall gray cast iron (TWGCI) can be seen as a potential material for the preparation of lightweight castings in automotive engineering applications. This article discusses the most important challenges for TWGCI: cooling rate, solidification, macrostructure, microstructure, and chilling tendency. It reviews the tensile properties and thermophysical properties of gray cast iron. The article describes the variables that influence molten iron preparation: charge materials, melting furnace thermal regime, chemical composition, modification and inoculation treatment, holding time/pouring procedure, mold properties (mold temperature, thermophysical properties of mold and mold coating), and casting design.

This article describes the applications, advantages, and disadvantages of three centrifugal casting processes as well as the equipment used. These processes are true centrifugal casting, semicentrifugal casting, and centrifuge mold casting. The article discusses the cooling, inoculation, fluxing, and extraction of castings. It reviews mold heating and coating techniques as well as the various molds used. The three most common defects observed in centrifugal castings are also discussed. The article concludes with information on the applications of centrifugal casting in investment casting and combustion synthesis as well as spin casting.

Interplays of metallurgical factors, such as dissolved oxygen, carbon, and silicon content, that control the molten metal from melting to pouring, have a decisive influence on the quality of the castings. This article focuses on the magnesium treatment and desulfurization carried out during inoculation and nucleation of molten cast iron, assisting in the formation of cast iron. The different types of cast irons are gray cast iron, nodular cast iron, compacted graphite iron, malleable cast iron, and alloyed cast iron. The article provides an overview of the melt treatment processes carried out in cast steel, wrought and cast aluminum, and copper materials.

Cast iron, which usually refers to an in situ composite of stable eutectic graphite in a steel matrix, includes the major classifications of gray iron, ductile iron, compacted graphite iron, malleable iron, and white iron. This article discusses melting, pouring, desulfurization, inoculation, alloying, and melt treatment of these major ferrous alloys as well as carbon and alloy steels. It explains the principles of solidification by describing the iron-carbon phase diagram, and provides a pictorial presentation of the basic microstructures and processing steps for cast irons.

The International Committee of Foundry Technical Associations has identified seven basic categories of casting defects: metallic projections, cavities, discontinuities, defective surfaces, incomplete casting, incorrect dimension, and inclusions or structural anomalies. This article presents some of the common defects in each of the seven categories in a table. It discusses common defects determined during the examination of samples of ductile cast iron in Elkem's research facility in Norway. The article reviews common defects, such as shrinkage cavities, blowholes, hydrogen pinholes, nitrogen defects, and abnormal graphite morphology, found in gray iron. It concludes with a discussion on surface defects in compacted graphite iron.

From the point of view of economics and ecology, thin-wall ductile iron (TWDI) castings can compete in terms of mechanical properties with the light castings made of aluminum alloys. This article discusses the effect of technological factors on the cooling rate and physicochemical state of the liquid metal for preparing thin-wall castings with good mechanical properties and performance while avoiding casting defects. It describes a variety of defects that may appear during the production of TWDI castings, such as casting skin anomalies (e.g., flake graphite, graphite segregation), graphite clusters, exploded graphite, slag inclusions, shrinkage porosity, eutectic chill and secondary carbides, and cold shuts. The article reviews the tensile, fatigue, impact, and wear properties of TWDI castings. It provides information on the production and applications of TWDI castings.

The morphology of the graphite particles in compacted graphite iron (CGI) is intermediate to the graphite particles found in gray iron or ductile iron. This article discusses the castability and product design of compacted graphite iron. The introduction of modern measurement and control technologies has made CGI a viable material for high-volume series production. The article describes the production of compacted graphite iron castings and the process control that depends on the production volume of components made from compacted graphite iron. It also discusses the process control for high-volume CGI commonly based on thermal analysis.

During the melting and solidification of cast irons, certain trace (minor) elements may unintentionally accumulate to an extent that they have a detrimental effect on the microstructure of castings. This article discusses the residual elements, trace elements, and tramp elements in cast irons. Elements that influence the matrix structure of cast irons are commonly classified as ferrite-promoting elements or pearlite-promoting elements. The article describes the effects of minor elements on microstructure and properties of cast irons. It discusses the use of a combination of tools to control the effects of minor elements on the structure and properties of cast irons. The article concludes with information on allowable levels of trace and tramp elements in cast irons.

This article discusses the production process, testing methods, quality control, and common defects found in heavy-section ductile iron (DI) castings, along with analyses of industrial examples. The common defects include shrinkage defects, graphite-particle-related defects, and chunk graphite defects. The recommended chemical compositions for certain section thicknesses in ductile iron grades are presented in a table. The article illustrates the relationship between microstructure and mechanical properties of DI by using either industrial examples or castings produced under laboratory conditions.