This chapter discusses the melting and conversion of superalloys and the solidification challenges they present. Superalloys have high solute content which can lead to untreatable defects if they solidify too slowly. These defects, called freckles, are highly detrimental to fatigue life. The chapter explains how and why freckles form as well as how they can be prevented. It describes the criteria for selecting the proper melting method for specific alloys based on melt segregation and chemistry requirements. It compares standard processes, including electric arc furnace/argon oxygen decarburization melting, vacuum induction melting, vacuum arc remelting, and electroslag remelting. It also addresses related issues such as consumable remelt quality, control anomalies, melt pool characteristics, and melt-related defects, and includes a section that discusses the processes involved in converting cast ingots into mill products.

Casting is the most economical processing route for producing titanium parts, and unlike most metals, the properties of cast titanium are on par with those of wrought. This chapter covers titanium melting and casting practices -- including vacuum arc remelting, consumable electrode arc melting, electron beam hearth melting, rammed graphite mold casting, sand casting, investment casting, hot isostatic pressing, weld repair, and heat treatment -- along with related equipment, process challenges, and achievable properties and microstructures. It also explains how titanium parts are produced from powders and how the different methods compare with each other and with conventional production techniques. The methods covered include powder injection molding, spray forming, additive manufacturing, blended elemental processing, and rapid solidification.

This chapter discusses the processes, procedures, and equipment used in the production of iron, steel, aluminum, and titanium alloys. It describes the design and operation of melting and refining furnaces, including blast furnaces, basic oxygen and electric arc furnaces, vacuum induction melting furnaces, and electroslag and vacuum arc remelting furnaces. It also covers casting, rolling, and annealing procedures and describes the basic steps in aluminum and titanium production.

This chapter describes the basic steps in the production of titanium ingots and their subsequent conversion to standards product forms. It explains how titanium ore is reduced to a spongy residue, then granularized, compacted, and melted (along with alloying additions) to form an ingot, which may be remelted several times to achieve the necessary properties. It also discusses the cause of defects and ingot imperfections and the benefits of billet reduction and grain-refinement processes.

This article discusses the steps in the primary processing of stainless steels: melting, refining, remelting, casting, and hot rolling. It provides information of the major categories of defects in hot rolled stainless steels, namely hot mill defects, inclusion-related defects, and hot ductility-related defects.

This chapter describes some of the more typical manufacturing practices, along with their benefits and limitations. The manufacturing practices covered include primary melting, electroslag remelting, rolling, hot and cold drawing, and continuous casting. The chapter discusses the advance and application of powder metallurgy. A few of the more recently introduced processes that hold considerable promise for producing tool steels or finished tools at a lower cost or with improved quality also are reviewed.

This chapter describes the processes involved in alloy production, including melting, casting, solidification, and fabrication. It discusses the effects of alloying on solidification, the formation of solidification structures, supercooling, nucleation, and grain growth. It describes the design and operation of melting furnaces as well as melting practices and the role of fluxing. It also discusses casting methods, nonferrous casting alloys, and atomization processes used to make metal powders.

This article discusses the effects of alloying on the properties and behaviors of maraging steels. It describes how maraging steels differ from conventional steels in that they are strengthened, not by carbon, but by the precipitation of intermetallic compounds. It explains how maraging steels typically have high levels of nickel, cobalt, and molybdenum with little carbon content and how that affects their dimensional stability, fracture toughness, weldability, and resistance to stress-corrosion cracking.

This chapter provides an overview of the types of melting furnaces and refractories for steel casting. It then presents information about arc furnace melting and induction melting cycles. The chapter also describes methods for the removal of phosphorous, the removal of sulfur, and the recovery of elements from slag. It then presents an overview of argon-oxygen-decarburization (AOD) refining and types of ladles. The chapter describes chemical analysis that is performed using either optical emission or x-ray spectrographs.

This appendix includes selected references on topics related to the production and application of superalloys, including properties and microstructure; melting/ingot breakdown; forging/powder metallurgy; machining, heat treating, joining, refurbishment/repair; investment casting; coatings/corrosion; and modeling.

This chapter provides an overview of beryllium casting practices and the challenges involved. It discusses the stages of solidification, the effect of cooling rate, the difficulty of heat removal, and the potential for hot cracking. It describes common melting techniques, including vacuum induction melting, vacuum arc melting, and electron beam melting, and some of the ways they have been used to cast beryllium alloys. The chapter also includes information on metal purification and grain refinement procedures.