This article describes two methods based on rolling of sheet. The first is roll welding, where two or more sheets or plates are stacked together and then passed through rolls until sufficient deformation has occurred to produce solid-state welds. The other is laser roll welding, which is a hybrid process based on a thin-melting interface for a lap joint of dissimilar-metal sheets using a roller and one-sided laser heating. The article discusses the types, advantages, and applications of roll welding and laser roll welding. It also provides a detailed discussion on the laser roll welding of dissimilar metals.

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.

Resistance seam welding (RSEW) is a process in which the heat generated by resistance to the flow of electric current in the work metal is combined with pressure to produce a welded seam. This article discusses the various classes of the RSEW process, namely roll spot welding, reinforced roll spot welding, and leak-tight seam welding. It provides information on the applications of lap seam weld, mash seam weld, and butt seam weld. The article reviews the advantages and limitations of seam welding compared to resistance spot welding, projection welding, and laser welding. It describes the four basic types of resistance seam weld machines: circular, longitudinal, universal, and portable. The article concludes with a discussion on weld quality and process control for seam welding.

Rolling is the process of reducing the thickness or changing the cross section of a workpiece by compressive forces applied through a set of rolls. This article emphasizes flat rolling and illustrates basic flat-rolling process used to reduce the thickness of a rectangular cross section. It provides a discussion on hot rolling, cold rolling, and warm rolling, as well as lubrication in rolling. The article reviews the lubrication for iron-base and nickel-base materials, light metals, copper-base alloys, and titanium alloys. It discusses the wear mechanism in rolling: abrasion, adhesion, and fatigue, as well as oxidative and corrosive wear. Surface modification techniques, such as hardening by induction heat treating, weld overlay, thermal spray coating, coating via physical vapor deposition (PVD), and laser surface treatment, are also discussed for improving roll service life.

Contour roll forming is a continuous process for forming metal from sheet, strip, or coiled stock into desired shapes of uniform cross section by feeding the stock through a series of roll stations equipped with contoured rolls. This article discusses the materials, roll-forming machines, tooling, and auxiliary equipment used in contour roll forming and its process variables. Tooling used in roll forming includes forming rolls and dies for punching and cutting off the material. The article discusses the additional tooling required in tube mills to weld, size, and straighten the tubes as they are produced on the machine. It describes the roll design for tube rolling and reviews the seam welding operations of pipe and tubing. The article discusses cross-sectional tolerances, the reshaping of round tubing, and factors that affect the quality, accuracy, and surface finish.

This article overviews the classification of welding processes and the key process embodiments for joining by various fusion welding processes: fusion welding with chemical sources for heating; fusion welding with electrical energy sources, such as arc welding or resistance welding; and fusion welding with directed energy sources, such as laser welding, electron beam welding. The article reviews the different types of nonfusion welding processes, regardless of the particular energy source, which is usually mechanical but can be chemical, and related subprocesses of brazing and soldering.

Hybrid laser arc welding (HLAW) is a metal joining process that combines laser beam welding (LBW) and arc welding in the same weld pool. This article provides a discussion on the major process variables for two modes of operation of HLAW, namely, stabilization mode and penetration mode. The major process variables for either mode of operation include three sets of welding parameters: the variables for the independent LBW and gas metal arc welding processes and welding variables that are specific to the HLAW process. The article discusses the advantages, limitations, and applications of the HLAW and describes the major components and consumables used for HLAW. The components include the laser source, gas metal arc welding source, hybrid welding head, and motion system. The article also describes the typical sources of defects and safety concerns of HLAW.

This article discusses the operation principles, advantages, limitations, process parameters, consumables or electrodes, the equipment used, process variations, and safety considerations of gas metal arc welding (GMAW). It reviews the important variables of the GMAW process that affect weld penetration, bead shape, arc stability, productivity, and overall weld quality. These include welding consumables, equipment settings, and gun manipulation. The major components of a GMAW installation such as a welding gun, shielding gas supply, electrode feed unit, power source, and associated controls are discussed.

The thermal spray community serves the printing industry with a variety of protective coatings applied on behalf of original equipment makers and end users. This article describes the applications of thermal spray coating for printing equipment such as engraver rolls, plate and blanket cylinders, corona rolls, and draw rolls.

Quenching and partitioning (Q&P) steel is a term used to describe a series of C-Si-Mn, C-Si-Mn-Al, or other steels subjected to the quenching and partitioning heat treatment process. This article discusses the Q&P steel's chemical compositions and mechanical properties, and provides an overview of the important background and product characteristics with a focus on the automotive sheet steel application. It schematically represents the continuous annealing process, consequent phase-transformation behaviors, and forming-limit curves of Q&P steels. The article describes the parameters associated with resistance spot welding, laser welding, and metal active gas welding. It also provides useful information of retained austenite volume fraction measured by x-ray diffraction and electron backscatter diffraction. The article also examines microstructure evolution during tensile testing at different strain levels using electron backscatter diffraction.

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.

Microjoining methods are commonly used to fabricate medical components and devices. This article describes key challenges involved during microjoining of medical device components. The primary mechanisms used in microjoining for medical device applications include microresistance spot welding (MRSW) and laser welding. The article illustrates the fundamental principles involved in MRSW and laser welding. The article presents examples of various microjoining methods used in medical device applications, including pacemaker and nitinol microscopic forceps.

This article describes the joint preparation, fit-up and design of various types of laser beam weld joints: butt joint, lap joint, flange joint, kissing weld, and wire joint. It explains the use of consumables for laser welding and highlights the special laser welding practices of steel, aluminum, and titanium engineering alloys. Laser weld quality and quality assessment are described with summaries of imperfections and how its operations contribute to providing repeatable and reliable laser welds. Relevant laser weld quality specifications are listed.

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.