Oxyfuel gas welding (OFW) is a manual process in which the metal surfaces to be joined are melted progressively by heat from a gas flame, with or without a filler metal. This article discusses the capabilities, advantages, and limitations of OFW. It describes the role of gases, such as oxygen, acetylene, hydrogen, natural gas, propane, and proprietary gases, in OFW. The article discusses the important elements of an OFW system, such as gas storage facilities, pressure regulators, hoses, torches, related safety devices, and accessories. It describes the sequence for setting up a positive-pressure welding outfit. The article provides information on forehand welding and backhand welding, as well as various joints used. It concludes with a discussion on repairs and alterations, as well as the safety aspects.

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.

This article describes some of the welding discontinuities and flaws characterized by nondestructive examinations. It focuses on nondestructive inspection methods used in the welding industry. The sources of weld discontinuities and defects as they relate to service failures or rejection in new construction inspection are also discussed. The article discusses the types of base metal cracks and metallurgical weld cracking. The article discusses the processes involved in the analysis of in-service weld failures. It briefly reviews the general types of process-related discontinuities of arc welds. Mechanical and environmental failure origins related to other types of welding processes are also described. The article explains the cause and effects of process-related discontinuities including weld porosity, inclusions, incomplete fusion, and incomplete penetration. Different fitness-for-service assessment methodologies for calculating allowable or critical flaw sizes are also discussed.

This article briefly reviews the general causes of weldment failures, which may arise from rejection after inspection or failure to pass mechanical testing as well as loss of function in service. It focuses on the general discontinuities observed in welds, and shows how some imperfections may be tolerable and how the other may be root-cause defects in service failures. The article explains the effects of joint design on weldment integrity. It outlines the origins of failure associated with the inherent discontinuity of welds and the imperfections that might be introduced from arc welding processes. The article also describes failure origins in other welding processes, such as electroslag welds, electrogas welds, flash welds, upset butt welds, flash welds, electron and laser beam weld, and high-frequency induction welds.

Oxyfuel gas cutting (OFC) includes a group of cutting processes that use controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. This article discusses the operation principles and process capabilities of the OFC. It reviews the properties and compositions of fuel types such as acetylene, natural gas, propane, propylene, and methyl-acetylene-propadiene-stabilized gas. The article describes the effects of OFC on base metal, including carbon and low-alloy steels, cast irons, and stainless steels. It provides information on light cutting, medium cutting, heavy cutting, and stack cutting. The article informs that the basic oxyfuel method can be modified to allow gas cutting of metals, such as stainless steel and most nonferrous alloys, that resist continuous oxidation.

This article provides a detailed discussion on the functions, applications, types, and selection criteria of exterior and interior rail coatings. It includes a discussion on the corrosivity, inspection/maintenance, and qualification of applicators/inspectors/facilities.

Oxyfuel gas cutting (OFC) includes a group of cutting processes that use controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. This article provides a detailed discussion on the principles of operation and the process capabilities of OFC. In addition to providing information on the equipment used, the article describes the properties of fuel gases (acetylene, natural gas). It also presents an overview of the effect of OFC on base metal and explains the application of OFC in cutting thin, medium, and thick sections, bars, and structural and close-tolerance shapes.

Aluminum casting in steel and iron permanent molds is used widely throughout industry, and the vast majority of permanent mold castings are made of aluminum and its alloys. There are several methods used to cast aluminum in permanent molds. This article focuses on permanent mold casting with molten aluminum fed by gravity, low pressure, vacuum and centrifugal pressure, and squeeze casting. It discusses the major variables that affect the life of permanent molds, including pouring temperature, casting shape, cooling methods, heating cycles, storage, and cleaning. The article reviews the basic components of mold coatings: refractory fillers, binder, and carrier. Casting defects and suggested corrective actions for permanent mold casting are summarized in a table. The article concludes with a discussion on thin-wall permanent-mold castings.

This article provides information on metals that can be cast in permanent molds. It describes the advantages, disadvantages, applications, and design of permanent castings. Following a discussion on the factors considered in mold design and material selection, the article details the application of mold coatings and examines the effects of major processing variables on mold life. The variables that determine mold temperature and measures for controlling it are reviewed, and the effects of short-term and long-term variables on the dimensional accuracy of permanent mold castings are explained. The article concludes with a discussion on the factors influencing the surface finish on permanent mold castings.

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.

This article describes the fundamental concepts of heat treatment simulation, including the physical events and their interactions, the heat treatment simulation software, and the commonly used simulation strategies. It summarizes material data needed for heat treatment simulations and discusses reliable data sources as well as experimental and computational methods for material data acquisition. The article provides information on the process data needed for accurate heat treatment simulation and the methods for their determination. Methods for validating heat treatment simulations are also discussed with an emphasis on the underlying philosophy for the selection and design of validation tests. The article also discusses the applications, capabilities, and limitations of heat treatment simulations via selected industrial case studies for a better understanding of the effect of microstructure, distortion, residual stress, and cracking in gears, shafts, and bearing rings.

This article focuses on marine coatings associated with protecting commercial and military vessels. It provides detailed information on the common issues and requirements encountered when coating ballast tanks, freeboard, topside, and decks of the vessel. The article describes the advent of ultra-high solids coatings technology, and reviews the marine-specific coatings such as antifouling and their mechanisms and common failure modes.

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.

Microstructural analysis of specialized types of magnetic materials is centered on the examination of optical, electron, and scanning probe metallographic techniques unique to magnetic materials. This article provides a comprehensive overview of magnetic materials, their characteristics and sample preparation procedures. It reviews the methods pertaining to the microstructural examination of bulk magnetic materials, including microscopy techniques specified to magnetic materials characterization, with specific examples. The techniques used in the study of magnetic domain structures (microstructure) include the magneto-optical Kerr method, the Faraday method, the Bitter technique, scanning electron microscopy (magnetic contrast Types I and II), scanning electron microscopy with polarization analysis, Lorentz transmission electron microscopy, and magnetic force microscopy. The article also illustrates the microstructure of different types of soft magnetic material and permanent magnets.