Weldments

A weldment is a component or structure formed by joining two or more pieces of material, typically metals, with welds. The resulting unit is treated as a single part in design, fabrication, and inspection. Weldments are common in frames, brackets, pressure vessels, piping systems, and manufactured assemblies where rigid, continuous joints are required.

Materials and processes: Weldments are made from metals such as carbon steel, stainless steel, aluminum, and titanium, among others. Common welding processes include shielded metal arc welding (SMAW), gas tungsten arc welding (GTAW or TIG), gas metal arc welding (GMAW or MIG), flux-cored arc welding (FCAW), and submerged arc welding (SAW). Process choice depends on material, thickness, position, production rate, and required weld quality. The weld metal and the heat-affected zone are assessed as part of the weldment’s performance.

Design and quality: Weldment design considers load paths, redundancy, and accessibility for welding and nondestructive testing. Joints include butt, fillet, lap, and corner configurations. Common defects include porosity, lack of fusion, slag inclusions, and cracking, which are mitigated by proper welding parameters, joint preparation, and post-weld treatment. Nondestructive testing methods such as dye penetrant, magnetic particle, radiography, and ultrasonic testing are used to verify weld integrity. Standards and codes, such as those from the American Welding Society (AWS) and ISO, govern fabrication, procedure qualification, and personnel qualification.

Manufacturing and lifecycle: The fabrication workflow typically involves planning and fixturing, welding, post-weld processing, and inspection. Welding procedure specifications (WPS) and welding procedure qualification records (WPQR) formalize acceptable procedures and records. Weldments are designed for service conditions, including mechanical loads, corrosion, and thermal stresses, and may require post-weld heat treatment or coatings.