arc welding

arc welding
Name	arc welding
Type	Manufacturing process
Invented	19th century
Inventor	Nikolay Benardos; Nikolai Slavyanov; Auguste de Méritens; C. L. Coffin
Industry	Shipbuilding; automotive; construction; aerospace; pipeline

arc welding is a group of welding processes that join metals by melting workpieces and filler metal using an electric arc generated between an electrode and the workpiece. Developed in the late 19th and early 20th centuries, the technique rapidly transformed heavy industries such as shipbuilding, railroad, and manufacturing by enabling stronger, faster, and more repeatable joints than earlier forge- and oxyfuel-based methods.

History

Early demonstrations and patents in the 1880s and 1890s by inventors such as Nikolay Benardos, Auguste de Méritens, and Nikolai Slavyanov established foundational approaches to electric arc utilization. Industrial adoption accelerated with contributions from engineers like C. L. Coffin at General Electric and the development of consumable electrodes and shielding concepts influenced by researchers working for firms such as Westinghouse Electric Corporation and British Thomson-Houston. Wartime demands during the First World War and Second World War stimulated mass training programs in welding, integration into shipyards like Harland and Wolff, and wide deployment by manufacturers including Ford Motor Company and Boeing. Postwar research at institutions such as the National Bureau of Standards and university labs advanced metallurgy, leading to modern standards developed by bodies like American Welding Society and International Organization for Standardization.

Principles and Types

Arc processes rely on sustaining an electrical arc to produce heat; process differentiation arises from electrode type, shielding, and current mode. Common processes include Shielded Metal Arc Welding (SMAW) pioneered in industrial workshops, Gas Metal Arc Welding (GMAW/MIG) advanced by engineers at Lincoln Electric, Gas Tungsten Arc Welding (GTAW/TIG) attributed to developments at Westinghouse and academic groups, Flux-Cored Arc Welding (FCAW) developed for heavy fabrication, Submerged Arc Welding (SAW) used in large structural work by firms such as Vought, and Plasma Arc Welding (PAW) emerging from aerospace research centers like NASA laboratories. Specialized methods such as Electroslag Welding and Electron Beam Welding were promoted by Russian Academy of Sciences and institutions serving Lockheed Martin and Northrop Grumman for thick-section joining. Welding automation progressed through programmable systems from companies like ABB and Fanuc used in automotive plants of General Motors and Toyota.

Equipment and Materials

Key equipment includes power sources (transformers, rectifiers, inverter supplies), electrode holders, torches, wire feeders from manufacturers like Lincoln Electric and ESAB, and gas supply systems using cylinders from suppliers such as Air Liquide and Linde plc. Consumables cover coated stick electrodes, solid or cored wires, and welding rods formulated by metallurgical firms including ArcelorMittal and Corus Group. Shielding gases such as argon and carbon dioxide commonly supplied by Praxair protect molten pools. Fixtures, preheating furnaces, and nondestructive testing devices—ultrasonic equipment by Olympus Corporation and radiography systems—assist in quality control. Standards for welding consumables and procedures are maintained by organizations like American Society for Testing and Materials and Det Norske Veritas.

Process Parameters and Metallurgy

Critical parameters include current type (AC/DC), polarity, voltage, travel speed, heat input, electrode diameter, and shielding composition; control strategies derive from studies at universities such as Massachusetts Institute of Technology and Imperial College London. Heat-affected zone behavior and solidification structures are analyzed with methods developed at Max Planck Society and Fraunhofer Society laboratories. Phase transformations in steels, stainless alloys, aluminum, and titanium affect toughness and corrosion resistance—metallurgists at firms like Carpenter Technology Corporation and research centers such as Oak Ridge National Laboratory established empirical models for weld cooling rates and microstructure evolution. Process modeling and finite element simulations by software vendors like ANSYS and Siemens PLM support distortion prediction and residual stress management for high-integrity structures used by Rolls-Royce and Siemens AG.

Safety and Health Hazards

Arc welding poses hazards including electric shock, arc rays causing retinal and skin injuries, fumes and particulate exposure linked to respiratory disease and metal fume fever, and thermal burns. Regulatory and advisory entities such as Occupational Safety and Health Administration, National Institute for Occupational Safety and Health, and Health and Safety Executive provide guidelines on ventilation, respirators, and exposure limits. Personal protective equipment standards promoted by American National Standards Institute and manufacturers like 3M specify helmets with appropriate shade filters, flame-resistant clothing, and welding gloves. Industrial hygiene programs implemented at shipyards like Meyer Werft and plants run by Siemens Energy emphasize training, monitoring, and substitution strategies to reduce hexavalent chromium and manganese exposure.

Applications and Industry Uses

Arc welding underpins fabrication in sectors such as shipbuilding at Chantiers de l'Atlantique, automotive assembly at Toyota Motor Corporation and Volkswagen, pressure vessel manufacture for companies like Emerson Electric, pipeline construction by contractors serving TransCanada Corporation, and aerospace assembly by Airbus and Boeing. Infrastructure projects employing bridge fabrication often reference standards from American Association of State Highway and Transportation Officials; heavy equipment makers such as Caterpillar Inc. and railcar builders like Bombardier rely on dedicated welding lines. Emerging applications include additive manufacturing research at Lawrence Livermore National Laboratory and repair welding in energy sectors for firms like ExxonMobil and Shell plc.

Category:Welding