Search Results for high-alloy iron

This article discusses the production, properties, and uses of high-alloy white irons. It explains how the composition and melt are controlled to produce a large volume of eutectic carbides, making these irons particularly hard and resistant to wear, and how the metallic matrix supporting the carbide phase can be adjusted via alloy content and heat treatment to optimize the balance between abrasion resistance and impact toughness. It also describes the effect of alloying elements and inoculants on various properties and behaviors and provides information on commercial alloy grades and applications.

Cast irons, like steels, are iron-carbon alloys but with higher carbon levels than steels to take advantage of eutectic solidification in the binary iron-carbon system. Like steel, heat treatment of cast iron includes stress relieving, annealing, normalizing, through hardening, and surface hardening. This chapter introduces solid-state heat treatment of iron castings, covering general considerations for heat treatment and discussing the processes, advantages, and disadvantages of heat treatment of cast iron.

The commercial relevance of cast irons is best understood in the context of the iron-carbon phase diagram, where their composition places them near the eutectic point, which sheds light on why they melt at lower temperatures than steel and why they can be cast into more intricate shapes. This chapter examines these unique properties and how they are derived. It begins by describing the basic metallurgy of cast iron, focusing on the eutectic reaction. It explains how to control the reaction and thus properties of cast iron by overcooling and inoculation. The chapter also discusses composition, microstructure, heat treatments, and the classification and casting characteristics of white, gray, ductile, malleable, compacted graphite, and special cast irons.

This article covers the metallurgy and properties of gray irons. It describes the classes or grades of gray iron, the types of applications for which they are suited, and the corresponding compositional ranges. It discusses the role of major, minor, and trace elements, how they are added, and how they affect various properties, behaviors, and processing characteristics. It explains how silicon, chromium, and nickel, in particular, improve high-temperature, corrosion, and wear performance.

This chapter provides a brief overview of nickel-iron-base, cobalt-base, and nickel-base superalloys, discussing their basic metallurgy and defining characteristics.

Iron and steel castings require cleaning as they come out of the shakeout units to remove any burned sand and sand that may remain stuck from the mold. This chapter presents the casting cleaning operation sequence. The sequence includes shot blasting; decoring or removal of cores from castings; degating or removal of runners, gates, and feeders; and flash removal and automation. The chapter also presents the objectives of heat treatment and discusses its processes. The chapter describes product quality control. Quality checks are grouped into three categories: material checks, product checks, and functional checks.

This chapter introduces the metallographer to the various types of steels and cast irons and explains how they are classified and defined. Classification and designation details are provided for plain carbon steels, alloy steels, and gray, white, ductile, and malleable cast irons.

Tool steels are the ferrous alloys used to manufacture tools, dies, and molds that shape, form, and cut other materials, including steels, nonferrous metals, and plastics. This chapter explores the considerations that make tool steels a very special class of steels, the long historical evolution of iron and steel manufacture, including steels for tools, and the development of tool steels as they emerged from the general class of iron and steel products.

This chapter discusses the crystal structures of steel and cast iron, the iron-iron carbide equilibrium diagram, microconstituents or phases in the iron-iron carbide phase diagram, the iron-carbon carbide-silicon equilibrium diagram of cast irons, and the influence on microstructure by base elements and alloying elements. Graphitization, cooling rates, and heat treatment effects are covered. There also is discussion on inoculation benefits, flake graphite types and typical applications, evolution of cast iron types, ASTM specification A247 for graphite shapes, and selection of the best molding process. A large table lists typical material choices for various applications.

This article discusses the compositions, structures, and properties of the most common grades of soft magnetic metals and permanent magnet alloys. It explains how alloying additions and impurities affect the magnetic properties of these materials, which include commercially pure and phosphorus irons, low-carbon and silicon steels, ferritic stainless steels, and nickel-iron and iron-cobalt alloys.

This article discusses the metallurgy and properties of ductile cast iron. 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 in particular detail, explaining how they make ductile iron more resistant to corrosion, heat, and wear.

The properties of cast iron are determined primarily by the form of carbon they contain, which in turn, is controlled by modifying compositions and cooling rates during casting. Certain alloys (such as Si, Al, Ni, Co, and Cu) promote graphite formation, while others (such as S, V, Cr, Sn, Mo, and Mn) promote the formation of cementite. This chapter examines the relative potencies of these alloys and their effect on microstructure. It covers the five most common commercial cast irons, including white, gray, ductile, malleable, and compacted graphite, describing their compositional ranges, distinguishing features, advantages, limitations, and applications.

Malleable iron has unique properties that justify its application in the metal working industry. This chapter discusses the advantages, limitations, and mechanical properties of malleable iron; provides a description of the malleabilization process; and presents manufacturing guidelines for malleable iron castings.

This article discusses the composition and morphology of compacted graphite (CG) iron relative to that of gray and ductile iron. It explains that the graphite in CG iron is intermediate in shape between the spheroidal graphite found in ductile iron and the flake graphite in gray iron, giving it distinct advantages in a number of applications. The article also discusses the role of melt treatment elements and explains how alloying and heat treatment affect tensile strength, hardness, toughness, and ductility.

The discovery and use of materials have shaped civilization since ancient times. This chapter traces the history of the use of metals from hammered copper estimated to be 11,000 years old to the development of electrolytically refined aluminum in 1884. The discussion covers the advent of the Bronze Age, extraction of metals from their respective ores, and the discovery of modern metals such as chromium, vanadium, platinum, and titanium.