This article discusses tubular products made from wrought carbon or alloy constructional steels, particularly pipe, specialty tubing, and oil country tubular goods. The article covers product classifications, available specifications, chemical compositions, sizes, and other dimensional attributes. Some of the common types of pipe are standard pipe, conduit pipe, piling pipe, pipe for nipples, transmission or line pipe, water main and water well pipe, and pressure pipe. Pipe in suitable sizes and most products classified as tubing, both seamless and welded, may be cold finished. Pressure tubes, a separate classification, include double-wall brazed tubing, structural tubing, welded mechanical tubing, continuous-welded cold-finished mechanical tubing, and seamless mechanical tubing.

This article discusses the applications and tensile properties of selected copper tube alloys, as well as the methods for producing copper tubular products, namely extrusion and rotary piercing. It explains the methods available for the finishing of copper tubular products, such as tube welding, cold drawing, and tube reducing. The article lists the standard dimensions and tolerances for several kinds of copper tubes and pipes in the ASTM specifications, along with other requirements for the tubular products.

This article discusses the classifications, specifications, applications and methods for producing welded and seamless steel tubular products, including pipes and tubes. Common types of pipes include standard pipe, conduit pipe, piling pipe, pipe for nipples, transmission or line pipe, water main pipe, oil country tubular goods, water well pipe, and pressure pipe. Pipes in suitable sizes, and most of the products classified as tubing, both seamless and welded, may be cold finished. Pressure tubes are given a separate classification by both the American Society for Testing and Materials (ASTM) and producers. The term tube covers three groups, including pressure tubes, structural tubing, and mechanical tubing.

This article presents effective stress equations that are based on the von Mises criterion, the Tresca criterion, and the Huddleston criterion. It describes the calculation of effective stresses for different cases: elastic stresses, steady-state creep stresses, stresses in a fully plastic case, and thermal stresses in a tube. The article illustrates the comparison of life predictions by the stress criteria and presents a simple mean diameter hoop stress equation, which is used for designing components. It also provides information on the multiaxial creep ductility of tubular components and multiaxial testing methods.

This article provides information on the application of nondestructive examination (NDE) technologies to tube and pipe products. These include modeling and simulation methods, eddy-current methods, magnetic methods, acoustic methods, and physical methods. A summary of nondestructive examination methods based on flaw type and product stage is presented in a table. The article also discusses in-service inspection of tubular products and presents an example that illustrates the importance of nondestructive testing (NDT) for welds in austenitic stainless steel tubing.

Wrought copper and copper alloys are produced in various mill-product forms for a variety of applications due to their high electrical conductivity, corrosion resistance, ease of fabrication, and good heat-transfer properties. This article describes the manufacturing processes used to produce wrought copper and copper alloys in the form of sheet and strip products, tubular products, and wire and cable. Common processes include melting, casting, hot and cold rolling, milling or scalping, annealing, cleaning, slitting, cutting, and leveling. In addition, the article discusses stress-relaxation characteristics of copper alloys.

Aluminum mill products are those that have been subjected to plastic deformation by hot- and cold-working mill processes such as rolling, extruding, and drawing, either singly or in combination. Microstructural changes associated with the working and with any accompanying thermal treatments are used to control certain properties and characteristics of the worked, or wrought, product or alloy. This article discusses the designation system, classification, product forms, corrosion and fabrication characteristics, and applications of wrought aluminum alloys. Commercial wrought aluminum products are divided into flat-rolled products (sheet, plate, and foil); rod, bar, and wire; tubular products; shapes; and forgings. The article discusses factors affecting the strengthening mechanisms, fracture toughness, and physical properties of aluminum alloys, in addition to the effects of alloying on the physical and mechanical properties. Important alloying elements and impurities are listed alphabetically as a concise review of major effects.

Normalizing of steel is a heat treating process that is often considered from both thermal processing and microstructural standpoints. In terms of thermal processing, normalizing is defined as heating of a ferrous alloy to a suitable temperature above the transformation range and then cooling it in air to a temperature substantially below the transformation range. This article provides information on the normalizing of carbon and alloy steels, and discusses the processes involved and the furnaces used in normalizing of steel forgings, bar and tubular products, and castings. It contains tables that list the typical normalizing temperatures for standard carbon and alloy steels and typical mechanical properties of selected carbon and alloy steels in hot-rolled, normalized, and annealed conditions.

This article summarizes the characteristics, material properties, and typical applications of aluminum alloy wrought products. It describes the most widely used worldwide alloy designation system and discusses five major categories, namely flat-rolled products; rod, bar, and wire; tubular products; shapes; and forgings. The article also discusses three widely used indexes to define the fracture resistance of aluminum alloys: notch toughness, tear resistance, and plane-strain fracture toughness. It also describes three types of corrosion attack of these alloys: general or atmospheric surface corrosion, stress-corrosion cracking, and exfoliation attack.

This article introduces the basic characteristics, processes, and product forms associated with the five major categories of aluminum wrought products, namely, flat-rolled products (sheet, plate, and foil); rod, bar, and wire; tubular products; profiles; and forgings. It summarizes the various product forms in which commonly used wrought aluminum alloys are available. The article also provides design guidelines for aluminum extrusions and discusses various forming methods.

Heat exchangers are devices used to transfer thermal energy between two or more fluids, between a solid surface and a fluid, or between a solid particulate and a fluid at different temperatures. This article first addresses the causes of failures in heat exchangers. It then provides a description of heat-transfer surface area, discussing the design of the tubular heat exchanger. Next, the article discusses the processes involved in the examination of failed parts. Finally, it describes the most important types of corrosion, including uniform, galvanic, pitting, stress, and erosion corrosion.

This article discusses the classification, characteristics and temper designations of wrought aluminum alloys. Wrought aluminum products are available as flat-rolled products such as sheets, plates, and foils; rods, bars, and wires; tubular products such as tubes and pipes; extruded shapes; forgings; and impacts. The article provides information on product economics, design and selection, including product dimension and dimension tolerances, and design and use of wrought product capabilities. Finally, it tabulates the specifications and standards for aluminum mill products.

Stainless steels are iron-base alloys containing minimum of approximately 11% Cr, and owing to its excellent corrosion resistance, are used for wide range of applications. These applications include nuclear reactor vessels, heat exchangers, oil industry tubular, chemical processing components, pulp and paper industries, furnace parts, and boilers used in fossil fuel electric power plants. The article provides a brief introduction on corrosion resistance of wrought stainless steel and its designations. It lists the chemical composition and describes the physical and mechanical properties of five major stainless steel families, of which four are based on the crystallographic structure of the alloys, including martensitic, ferritic, austenitic, or duplex. The fifth is precipitation-hardenable alloys, based on the type of heat treatment used. The article further discusses the factors in the selection of stainless steel, namely corrosion resistance, fabrication characteristics, product forms, thermally induced embrittlement, mechanical properties in specific temperature ranges, and product cost.

The main objective for the study of combined-stress fatigue is to obtain fatigue data for axles and to find the criterion for fatigue limit under combined stress. This article begins with a description of the stress states of combined stress and stress fields near crack tips. It provides an account of the various biaxial and multiaxial fatigue testing methods, specimen geometries, and stress intensity factors important in the study multiaxial fatigue. Widely used test methods are the torsion-rotating bending fatigue test and biaxial and triaxial fatigue tests. Common specimen geometries include rectangular plate specimens, cruciform specimens, compact tension shear specimens, compact shear specimens, mode II crack growth specimen, circumferentially notched cylindrical specimens, tubular specimens containing a slit, and solid cylindrical specimens containing a small hole or initial crack.

A wide range of flow-formed open- and close-ended shapes are currently available in a variety of difficult-to-form materials, including titanium alloys and nickel-base super alloys. This article describes the two basic methods of flow forming that are characterized by the position of the rolls during the forming process. The flow forming methods include staggered-roll flow forming process and in-line flow-forming process. Typical mechanical properties of flow-formed materials in various conditions are summarized in a table. Proper process controls and subsequent product qualification tests are critical to assure optimal performance of the flow-formed tubular component. The article discusses the most commonly required process control parameters and the effects of forming speed and temperature in the flow forming process.

Cold extrusion is a push-through compressive forming process with the starting material (billet/slug) at room temperature. This article provides information on the different types of steels that can be cold extruded. Mechanical presses and hydraulic presses that are specifically designed for cold extrusion with high rigidity, accurate alignment, and long working strokes are described. The article details the factors that are critical in cold extrusion: punch design, die design, and tool design. It summarizes the role of lubricants during extrusion of steel, such as soap lubricant and polymer lubricants. The article describes several procedures for extruding specific steel parts such as tubular parts and stepped shafts. It lists problems such as tool breakage and galling or scoring of tools and explains cold extrusion of aluminum, copper, and nickel alloy parts. The article also discusses the impact extrusion of magnesium alloys.

Radial forging is a hot- or cold-forming process that uses two or more radially moving anvils or dies to produce solid or tubular components with constant or varying cross sections along their lengths. This article focuses on the workpiece configuration, workpiece materials, machines, dies, advantages, and limitations of radial forging. It concludes with a discussion on the applications of radial forging.

This article describes processes and equipment that are used to produce composite tubular parts. The processes include sheeting, pattern cutting, tube rolling, shrink tape debulking, and finishing. The article provides a discussion on materials that are most suitable for tube rolling: preimpregnated materials and unidirectional tapes. The article also discusses wrapping techniques of cylindrical and tapered tubes, such as convolute and spiral wrapping.

Film radiography requires the development of the exposed film so that the latent image becomes visible for viewing. It describes the general characteristics of film, including speed, gradient, and graininess, and the factors affecting film selection and exposure time. The article discusses the three major inspection techniques for tubular sections, namely, the double-wall, double-image technique; the double-wall, single-image technique; and the single-wall, single-image technique. It illustrates the arrangements of penetrameters and identification markers for the radiography of plates, cylinders, and flanges. The article discusses various control methods, including the use of lead screens; protection against backscatter and scatter from external objects; and the use of masks, diaphragms, collimators, and filtration. The radiographic appearance of specific types of flaws is also discussed. The article concludes with a discussion on two methods of radiographic film processing: manual and automatic processing.

Analyzing the structure of composite materials is essential for understanding how the part will perform in service. Assessing fiber volume variations, void content, ply orientation variability, and foreign object inclusions helps in preventing degradation of composite performance. This article describes the optical microscopy and bright-field illumination techniques involved in analyzing ply terminations, prepreg plies, splices, and fiber orientation to provide the insight necessary for optimizing composite structure and performance.