Malleable iron is a cast ferrous metal that is initially produced as white cast iron and is then heat treated to convert the carbon-containing phase from iron carbide to a nodular form of graphite called temper carbon. This article provides a discussion on the melting practices, heat treatment, microstructure, production technologies, mechanical properties, and applications of ferritic, pearlitic, and martensitic malleable iron.

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.

Carbon and low-alloy steels are considered resistant only to very mild corrosives, while the various high-alloy grades are applicable for varying situations from mild to severe services, depending on the particular conditions involved. This article describes the factors that must be considered, by alloy casting users, in material selection. It presents compositions of cast steels tested in atmospheric corrosion in a tabular form. The rate of corrosion of a material in an environment can generally be estimated with confidence only from long-term tests. The article graphically presents the results of a research program that compared the corrosion resistance of nine cast steels in marine and industrial atmospheres. It illustrates the comparison of corrosion rates of cast steels, malleable cast iron, and wrought steel after 3 years of exposure in two atmospheres and provides the conclusions drawn from these tests.

Malleable iron is a type of cast iron that has most of its carbon in the form of irregularly shaped graphite nodules. This article tabulates the typical composition of malleable iron and specifications, and applications of malleable iron castings. It discusses the metallurgical control of malleable irons with emphasis on its composition and heat treatment. The article provides information on the specifications and mechanical properties of different types of malleable irons, such as ferritic, pearlitic, and martensitic malleable irons.

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.

Cast irons may be compared with steels in their reactions to hardening. However, because cast irons (except white iron) contain graphite and substantially higher percentages of silicon, they require higher austenitizing temperatures. This article describes the effect of heat treatment processes such as annealing, normalizing, surface hardening, tempering, stress relieving, quenching, and austempering, on hardness and tensile properties of cast irons, namely gray irons, ductile irons, malleable irons, and austenitic irons.

Cast irons primarily are iron alloys that contain more than 2% carbon and from 1 to 3% silicon. This article provides a description of iron-iron carbide-silicon system; and discusses the classification, composition, and characteristics of cast irons, such as gray, ductile, malleable, compacted graphite, and white cast iron. A table shows the correspondence between commercial and microstructural classification, as well as final processing stage in obtaining common cast irons.

This article provides a brief review of the classification and characteristics of cast irons. It describes the processes used to clean iron castings, including mechanical cleaning and finishing and nonmechanical cleaning. The article discusses surface treatments used to extend casting life when resistance to corrosion, wear, and erosion is required. The common methods include electroplating, electroless plating, hardfacing, weld cladding, surface hardening, porcelain enameling, and organic coatings.

This article is an atlas of fractographs that helps in understanding the causes and mechanisms of fracture of pearlitic malleable and ferritic malleable white irons, and in identifying and interpreting the morphology of fracture surfaces. The fractographs illustrate the fracture sequence, localized plastic deformation, and microcrack initiation and propagation of these irons.

This article provides information on the general characteristics, composition, uses, applications and specifications for standard grades of ductile iron. It describes the manufacturing and metallurgical process control procedures, including testing and inspection, and heat treatment. The article also talks about the effects of composition, graphite shape, and section size on the mechanical properties of ductile iron. Tables and graphs provide helpful information on the tensile properties, compressive properties, torsional properties, damping capacity, impact properties, fracture toughness, fatigue strength, and elevated-temperature properties of ductile iron.

This article begins with a description of the classes and grades of ductile iron. It discusses the factors affecting the mechanical properties of ductile iron. The article reviews the hardness properties, tensile properties, shear and torsional properties, compressive properties, fatigue properties, fracture toughness, and physical properties of ductile iron and compares them with other cast irons to aid the designer in materials selection. It concludes with information on austempered ductile iron.

This article begins with an overview of classes and applications of gray iron. It discusses the castability of gray iron in terms of section sensitivity and fluidity. The article provides information on the dimensions of prevailing sections recommended for gray irons and reviews the properties and specifications of test bar. It discusses the properties of gray iron, such as fatigue limit, pressure tightness, impact resistance, machinability, and dimensional stability, at both room and elevated temperature. Wear behavior of gray iron castings during sliding contact under conditions of normal lubrication is also discussed. The article reviews the use of alloys and heat treatment to modify as-cast properties. It concludes with information on physical properties of gray iron castings.

This article discusses the five basic matrix structures in cast irons: ferrite, pearlite, bainite, martensite, and austenite. The alloying elements, used to enhance the corrosion resistance of cast irons, including silicon, nickel, chromium, copper, molybdenum, vanadium, and titanium, are reviewed. The article provides information on classes of the cast irons based on corrosion resistance. It describes the various forms of corrosion in cast irons, including graphitic corrosion, fretting corrosion, pitting and crevice corrosion, intergranular attack, erosion-corrosion, microbiologically induced corrosion, and stress-corrosion cracking. The cast irons suitable for the common corrosive environments are also discussed. The article reviews the coatings used on cast irons to enhance corrosion resistance, such as metallic, organic, conversion, and enamel coatings. It explains the basic parameters to be considered before selecting the cast irons for corrosion services.

Alloy cast irons are casting alloys based on the Fe-C-Si system that contain one or more alloying elements added to enhance one or more useful properties. This article discusses the composition of different types of alloy cast iron, including white cast irons, corrosion-resistant cast irons, heat-resistant cast irons, and abrasion-resistant cast irons. It provides information on the effect of the alloying element on their high-temperature properties. The article also discusses the microstructure and mechanical properties of alloy cast irons.

The term cast iron designates a group of materials that contain more than one constituent in their microstructure due to excess carbon that result in unique characteristics such as the fracture appearance and graphite morphology. This article discusses the classification of cast iron and the various metallurgical aspects, such as composition, alloying element, solidification, and graphite morphologies, of different types of cast iron. It describes the physical properties for various cast irons and the influence of microstructure and chemical composition on each property. The article provides a detailed account on thermal properties, conductive properties, magnetic properties, and acoustic properties of cast iron. It also discusses heat treatment, namely, stress relieving, annealing, normalizing, through hardening, and surface hardening. The article presents a discussion on the welding, machining and grinding, and coating of the types of cast iron.

This article focuses on the mechanisms, models, prevention, correction, and effects associated with decarburization inherited from semi-finished product processing prior to induction heating. It discusses the diffusion of carbon in austenitic iron, which has a face-centered cubic crystal structure that provides an interstitial path for the migration of the relatively small carbon atoms. The article describes the evolution of steel microstructure with progressive decarburization (in air) to a steady-state carbon gradient using an iron-iron carbide phase diagram. It provides useful information on the impact of alloying on vulnerability to decarburization, and the impact of decarburization on the mechanical properties of steels and cast irons. The article also describes the technological operations that potentially cause decarburization and the practical implications for induction hardening.

An understanding of the influence of microstructure on machinability can provide an insight into more efficient machining and the correct solution to problems. Providing numerous microstructures to depict examples, this article describes the relationship between the microstructure and machinability of cast irons, steels, and aluminum alloys. It presents data on hardness values and the effect of the matrix microstructure of cast iron on tool life. It also explains how a higher inclusion count improves the machinability of steels and why aluminum alloys can be machined at very high speeds.

Proper sectioning of the surface to be examined is a very important step in preparing steel specimens. The first step in preventing damage to the metallurgical structure is to minimize the amount of sectioning that is done. This article discusses the various metallographic techniques, namely mounting, grinding, polishing, and etching involved in the microstructural analysis of carbon and alloy steels, case hardening steels, cast iron, ferrous powder metallurgy alloys, wrought and cast stainless steels, tool materials, steel castings, iron-chromium-nickel heat-resistant casting alloys and different product forms of steels.

The Atlas of Fractographs contains more than 1,300 fractographs, corresponding to 30 materials, including common grades of iron and steel, nonferrous metals and alloys, composites, and polymers. This article serves as the table of contents, describing how the information in the Atlas is organized and how the fractographs are laid out. It also provides a summary of the various causes or modes of fracture, including cleavage, dimple rupture, fatigue fracture, and decohesion.

This article presents a table that lists the linear thermal expansion of selected metals and alloys. These include aluminum, copper, iron, lead, magnesium, nickel, tin, titanium, and zinc and their alloys. Thermal expansion is presented for specific temperature ranges.