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.

Corrosion failures of welds can occur even when the proper base metal and filler metal have been selected, industry codes and standards have been followed, and welds have been deposited that possess full weld penetration and have proper shape and contour. This chapter describes some of the general characteristics associated with the corrosion of weldments. The role of macro- and microcompositional variations, a feature common to weldments, is emphasized in this chapter to bring out differences that need to be realized in comparing the corrosion of weldments to that of wrought materials. The discussion covers the factors influencing corrosion of weldments, microstructural features of weld microstructures, various forms of weld corrosion, and welding practice to minimize corrosion.

This chapter describes issues related to corrosion of carbon steel weldments and remedial measures that have proven successful in specific cases. The forms of corrosion covered includes preferential heat affected zone corrosion, preferential weld metal corrosion, and galvanic corrosion. Industrial case studies demonstrating the necessity for testing each galvanic couple in the environment for which it is intended are presented. The chapter also discusses various factors associated with stress-corrosion cracking in oil refineries.

Carbon and low-alloy steels are the most frequently welded metallic materials, and much of the welding metallurgy research has focused on this class of materials. Key metallurgical factors of interest include an understanding of the solidification of welds, microstructure of the weld and heat-affected zone (HAZ), solid-state phase transformations during welding, control of toughness in the HAZ, the effects of preheating and postweld heat treatment, and weld discontinuities. This chapter provides information on the classification of steels and the welding characteristics of each class. It describes the issues related to corrosion of carbon steel weldments and remedial measures that have proven successful in specific cases. The major forms of environmentally assisted cracking affecting weldment corrosion are covered. The chapter concludes with a discussion of the effects of welding practice on weldment corrosion.

This chapter covers the friction and wear behaviors of cast irons. It describes the microstructure and metallurgy of gray, white, malleable, and ductile cast irons, their respective tensile properties, and their suitability for applications involving friction, various types of erosion, and adhesive and abrasive wear.

Duplex stainless steels are two-phase alloys based on the iron-chromium-nickel system. Duplex stainless steels offer corrosion resistance and cost advantages over the common austenitic stainless steels. Although there are some problems with welding duplex alloys, considerable progress has been made in defining the correct parameters and chemistry modifications for achieving sound welds. This chapter provides a basic understanding of the development, grade designations, microstructure, properties, and general welding considerations of duplex stainless steel. It also discusses the influence of ferrite-austenite balance on corrosion resistance and the influence of different welding conditions on various material properties of alloy 2205 (UNS S31803).

Failure analysis of steel welds may be divided into three categories. They include failures due to design deficiencies, weld-related defects usually found during inspection, and failures in field service. This chapter emphasizes the failures due to various discontinuities in the steel weldment. These include poor workmanship, a variety of hydrogen-assisted cracking failures, stress-corrosion cracking, fatigue, and solidification cracking in steel welds. Hydrogen-assisted cracking can appear in four common forms, namely underbead or delayed cracking, weld metal fisheyes, ferrite vein cracking, and hydrogen-assisted reduced ductility.

This chapter covers coatings and treatments that are used to improve the friction and wear behaviors of materials. It describes modifications that work by hardening contacting surfaces, including heat treating, vacuum coating, thermal spray, and plating, and those that separate or lubricate surfaces, including solid film, chemical conversion, and vacuum coatings, surface oiling and texturing, and lubricating platings. It compares and contrasts methods based on thickness and depth and their relative effect on friction, erosion, and wear.

Nickel-base alloys used for low-temperature aqueous corrosion are commonly referred to as corrosion-resistant alloys (CRAs), and nickel alloys used for high-temperature applications are known as heat-resistant alloys, high-temperature alloys, or superalloys. The emphasis in this chapter is on the CRAs and in particular nickel-chromium-molybdenum alloys. The chapter provides a basic understanding of general welding considerations and describes the welding metallurgy of molybdenum-containing CRAs and of nickel-copper, nickel-chromium, and nickel-chromium-iron CRAs. It discusses the corrosion behavior of nickel-molybdenum alloys and nickel-chromium-molybdenum alloys. Information on the phase stability and corrosion behavior of nickel-base alloys is also included.

This chapter discusses various factors that affect corrosion of stainless steel weldments. It begins by providing an overview of the metallurgical factors associated with welding. This is followed by a discussion on preferential attack associated with weld metal precipitates in austenitic stainless steels as well as several forms of corrosion associated with welding. The effects of gas-tungsten arc weld shielding gas composition and heat-tint oxides on corrosion resistance are then covered. Microbiological corrosion of butt welds in water tanks is also illustrated. In addition, the chapter provides information on corrosion of ferritic and duplex stainless steel weldments.

Arc welding applies to a large and diversified group of welding processes that use an electric arc as the source of heat to melt and join metals. This chapter provides a detailed overview of specific arc welding methods: shielded metal arc welding, flux cored arc welding, submerged arc welding, gas metal arc welding, gas tungsten arc welding, plasma arc welding, plasma-GMAW welding, electroslag welding, and electrogas welding. The basic characteristics of gases used for shielding during arc welding are briefly discussed.

This chapter provides a basis for understanding the influence of stainless steel alloy composition and metallurgy on the welding process, which involves complex dynamics associated with melting, refining, and thermal processing. It begins with an overview of the welding characteristics of the categories of stainless steels, namely austenitic, duplex, ferritic, martensitic, and precipitation-hardening stainless steels. This is followed by a discussion of the selection criteria for materials to be welded. Various welding processes used with stainless steel are then described. The chapter ends with a section on some of the practices to ensure safety and weld quality.

Managing corrosion continues to be a challenge for operators of modern boilers worldwide. This chapter addresses the corrosion-related problems that can occur in boilers burning municipal solid waste (MSW). It describes corrosion mechanisms associated with different environments and alloys. It also discusses corrosion protection methods for furnace waterwalls and superheater tubes in waste-to-energy boilers.

Joining comprises a large number of processes used to assemble individual parts into a larger, more complex component or assembly. The selection of an appropriate design to join parts is based on several considerations related to both the product and the joining process. Many product design departments now improve the ease with which products are assembled by using design for assembly (DFA) techniques, which seek to ensure ease of assembly by developing designs that are easy to assemble. This chapter discusses the general guidelines for DFA and concurrent engineering rules before examining the various joining processes, namely fusion welding, solid-state welding, brazing, soldering, mechanical fastening, and adhesive bonding. In addition, it provides information on several design considerations related to the joining process and selection of the appropriate process for joining.

Aluminum is the second most widely used metal in the world. It is readily available, offers a wide range of properties, and can be shaped, coated, and joined using a variety of methods. This chapter discusses some of the key attributes of wrought and cast aluminum alloys and the classifications, designations, and grades of available product forms. It also explains how aluminum alloys are used in aerospace, automotive, rail, and marine applications as well as in building and construction, electrical products, manufacturing equipment, packaging, and consumer durables such as appliances and furniture.

This chapter covers the basics of weldability of cast steels such as carbon and low alloy steels, corrosion-resistant high alloy steels, nickel-base alloys, heat-resistant high alloy steels, and wear-resistant high austenitic manganese steels. It provides an overview of weld overlay and hard facing; cast-weld construction; and plasma arc cutting and plasma arc welding. The chapter discusses different types of welding processes. These include shielded metal-arc welding, air carbon arc cutting process, gas tungsten-arc welding, gas metal-arc welding process, flux-cored arc welding, submerged arc welding, and electroslag and electro-gas welding.

Martensitic stainless steels are essentially iron-chromium-carbon alloys that possess a body-centered tetragonal crystal structure (martensitic) in the hardened condition. Martensitic stainless steels are similar to plain carbon or low-alloy steels that are austenitized, hardened by quenching, and then tempered for increased ductility and toughness. This chapter provides a basic understanding of grade designations, properties, corrosion resistance, and general welding considerations of martensitic stainless steels. It also discusses the causes for hydrogen-induced cracking in martensitic stainless steels and describes sulfide stress corrosion resistance of type 410 weldments.

The case for using stainless steel in appliances of all types, whether they are commercial or residential, relates to it being able to provide the best value over the intended service life. This chapter describes some of the qualities in any material considered for food contact, namely chemical neutrality, biological neutrality, and cleanliness. A vast majority of stainless steel applications in commercial and residential equipment are also discussed.

This chapter describes the processes involved in the fabrication of wrought and cast metal products. It discusses deformation processes including bending and forming, material removal processes such as milling, cutting, and grinding, and joining methods including welding, soldering, and brazing. It also discusses powder consolidation, rolling, drawing and extrusion, and common forging methods.

The increased use of advanced high-strength steels to achieve weight reduction in automobiles has led to the development of innovative tool designs and manufacturing processes. Among these technologies and processes are: real-time process control, active drawbeads, active binders, flexible binders, and flexible rolling. This chapter presents the implementation, advantages, disadvantages, and applications of these processes and technologies.