Electric arc cutting is used on ferrous and nonferrous metals for rough severing, such as removing risers or scrap cutting, as well as for more closely controlled operations. This article describes the operating principles, equipment selection, process variables, and safety measures recommended for plasma arc cutting and air carbon arc cutting. Special applications of electric arc cutting, including shape cutting, gouging, and underwater cutting, are also discussed. The article provides information on other electric arc cutting methods, namely, the exo-process and oxygen arc cutting. It concludes with information on the seldom-used electric arc cutting methods, such as shielded metal arc cutting, gas metal arc cutting, and gas tungsten arc cutting.

This article is a compilation of definitions for terms related to welding fundamentals and all welding processes. The processes include arc and resistance welding, friction stir welding, laser beam welding, explosive welding, and ultrasonic welding.

Plasma arc cutting (PAC) is an erosion process that utilizes a constricted arc in the form of a high-velocity jet of ionized gas to melt and sever metal in a narrow, localized area. This article discusses the process description, equipment, gases, operating sequence, process considerations, and applications of PAC. It concludes with a discussion on the safety measures associated with the PAC process.

This article discusses the operating principles, types, and applications of shearing and slitting of different forms of steel, including plates, flat sheets, bars, coiled sheet and strips. In addition, it provides a detailed account of the cutting methods such as oxyfuel gas cutting, plasma arc cutting, oxygen arc cutting, laser beam cutting, and air carbon arc cutting and gouging, describing their process capabilities, equipment used, operating principles and parameters, and factors affecting their efficiency.

This article focuses on the mechanical and nonmechanical cutting methods used in metal fabrication industries. The most prevalent equipment used for mechanical cutting includes shears, iron workers, nibblers, and band saws. Nonmechanical methods of cutting include gas cutting, electric arc cutting, and laser cutting. The article concludes with information on the advantages of abrasive waterjet cutting, which is an alternative to laser cutting, gas cutting, and plasma cutting.

This article is a compilation of tables summarizing the fusion welding process. Included in the article is a table that presents the various fusion welding and cutting processes and their applications. Information on the general characteristics of arc welding processes is tabulated. The article also contains a list of the various criteria for selecting the suitable welding process for carbon steels.

Safety is an important consideration in all welding, cutting, and related work. This article discusses the basic elements of safety general to all welding, cutting, and related processes. It includes safety procedures common to a variety of applications. The most important component of an effective safety and health program is management support and direction. The article reviews the role of management, training, housekeeping, and public demonstrations in welding safety to minimize personal injury and property damage. It provides information on the safety measures for eye and face protection in various welding and cutting operations. Injuries and fatalities from electric shock in welding and cutting operations can occur if proper precautionary measures are not followed. The article discusses the electrical safety aspects to be considered for various welding and cutting operations.

This article presents an overview of the rules, regulations, and techniques implemented to minimize the safety hazards associated with welding, cutting, and allied processes. Safety management, protection of the work area, process-specific safety considerations, and robotic and electrical safety are discussed. The article explains the use of personal protective equipment and provides information on protection against fumes, gases, and electromagnetic radiation. It concludes with a discussion on safe handling of compressed gases as well as the prevention and protection of fire and explosion.

The shielding gas used in an arc welding process has a significant influence on the overall performance of the welding system. These gases are argon, helium, oxygen, hydrogen, nitrogen, and carbon dioxide. This article discusses the shielding gas selection criteria for plasma arc welding, gas metal arc welding, and flux cored arc welding. It describes the basic properties of shielding gases, namely, dissociation, recombination, reactivity potential, oxidation potential, and gas purity. The article also provides information on the influence of the shielding gas on weld mechanical properties and self-shielded flux cored arc welding.

The shielding gas used in a welding process has a significant influence on the overall performance of the welding system. This article discusses the basic properties of a shielding gas in terms of ionization potential, thermal conductivity, dissociation and recombination, reactivity/oxidation potential, surface tension, gas purity, and gas density. It describes the characteristics of the components of a shielding gas blend. The article discusses the selection of shielding gas for gas-metal arc welding (GMAW), gas-tungsten arc welding (GTAW), and plasma arc welding (PAW), as well as the influence of shielding gas on weld mechanical properties. It concludes with a discussion on flux-cored arc welding.

This article provides information on the various types of welds and joints. It reviews the weld joint design considerations: the ability to transfer load and the cost. The article explains the throat size and weld size requirements of fillet welds, and presents a comparison of fillet and groove welds. It details the various design considerations for groove-weld selection, including the groove angle, root opening, and depth of the groove. The article also describes the methods of edge preparation and concludes with an illustration of the recommended proportions of grooves for arc welding.

Repair and maintenance of parts and components is carried out as a logical procedure that ensures the production of a usable and safe component or it can be approached haphazardly. This article describes the requirements and repair techniques of arc and oxyfuel welding processes to repair weld defects and structural failures. It further discusses the preliminary assessment and base-metal preparation involved in weld repair. Furthermore, the article provides information on the general repair guidelines that are followed to ensure successful weld repairs of both ferrous (carbon steels, cast irons, and stainless steels) and nonferrous (titanium) base metals.

Laser beam machining removes, melts, or thermally modifies a material by focusing a coherent beam of monochromatic light on the workpiece. This article describes the principal lasers used in metal processing: neodymium-glass, carbon dioxide, and neodymium-doped yttrium aluminum garnet lasers. It discusses the operating parameters of concern in percussion drilling and trepanning. The process variables in surface treatment and laser cutting, as well as the operating parameters of concern in laser welding are reviewed. The article also explains the various categories of surface treatment: heat treating, cladding, surfacing, glazing, and marking.

Most welding lasers fall into the category of fiber, disc, or direct diode, all of which can be delivered by fiber optic. This article provides a comparison of the energy consumptions and efficiencies of laser beam welding (LBW) with other major welding processes. It discusses the two modes of laser welding: conduction-mode welding and deep-penetration mode welding. The article reviews the factors of process selection and procedure development for laser welding. The factors include power density, interaction time, laser beam power, laser beam diameter, laser beam spatial distribution, absorptivity, traverse speed, laser welding efficiency, and plasma suppression and shielding gas. The article concludes with a discussion on laser cutting, laser roll welding, and hybrid laser welding.

Gas-metal arc welding (GMAW) is an arc welding process that joins metals together by heating them with an electric arc that is established between a consumable electrode (wire) and a workpiece. This article discusses the advantages and limitations, operating principle, metal transfer mechanisms, and process variables of the GMAW process. The process variables include welding current, polarity, arc voltage, travel speed, electrode extension, electrode orientation, and electrode diameter. The major components of the basic equipment for a typical GMAW installation are discussed. The article also describes two consumable elements, such as electrode and shielding gas, of the GMAW process. It concludes with information on the safety aspects.

This article discusses the principles of operation, equipment needed, applications, and advantages and disadvantages of various fusion welding processes, namely, oxyfuel gas welding, electron beam welding, stud welding, laser beam welding, percussion welding, high-frequency welding, and thermite welding.