Welding, as a key process in industrial production for achieving permanent joining of materials, directly impacts product structural integrity, operational reliability, and personal safety. Because the welding process involves multiple variables such as heat input, metallurgical reactions, stress distribution, and process parameters, the lack of unified and strict execution standards can easily lead to defects and performance discrepancies. Therefore, establishing and implementing a scientific welding execution standard system is a necessary prerequisite for achieving standardized welding operations, traceable results, and controllable quality.
Welding execution standards cover the entire chain, including design, materials, processes, personnel qualifications, equipment, and inspection, and rely on national, industry, and international standards to form a hierarchical and complementary network of standards. my country's welding standards system is primarily based on the GB series. For example, GB/T 985.1, "Recommended Grooves for Gas Welding, Shielded Metal Arc Welding, Gas Shielded Welding and High Energy Beam Welding," specifies processing requirements for different joint types. GB 50661, "Code for Welding of Steel Structures," clarifies the welding procedure qualification, construction, and acceptance details for steel structures in buildings and bridges. In the field of pressure equipment, NB/T 47014, "Welding Procedure Qualification for Pressure Equipment," provides detailed regulations on welding methods, base metal and weldment matching, preheating, and post-heating regimes. Internationally, ISO, AWS (American Society of Welding), and EN (European Standards) are frequently referenced in multinational projects to ensure technical compatibility and mutual recognition of quality.
The standards implemented during the design phase require that the weld joint type, groove dimensions, and processing accuracy conform to the drawings and relevant specifications to avoid defects such as incomplete penetration and slag inclusions caused by geometric mismatches. Material selection standards emphasize the compatibility of base metal and weldment, including chemical composition, mechanical properties, and weldability assessment, and consider corrosion resistance, heat resistance, or low-temperature toughness requirements under specific working conditions. Welding Procedure Qualification (WPS/PQR) is a core component of standard implementation. It involves simulating actual production conditions through trial welding and testing to verify the feasibility of process parameters and generate reusable work instructions. Processes that have not passed qualification cannot be used in formal production.
Personnel qualification standards are the human resource foundation for quality assurance. Welders must undergo skills training and assessment according to NB/T 47015 or relevant standards, obtain operating certificates for the corresponding welding methods and material categories, and undergo periodic review within the validity period. Special processes (such as pressure equipment and nuclear power structures) require even stricter specific qualification requirements. Equipment standards specify the performance parameters and verification cycles of welding power sources, control devices, gas supply systems, and auxiliary devices to ensure stable, safe, and controllable output.
The welding process must strictly follow the qualified welding procedure documents, controlling heat input, interpass temperature, welding sequence, and deformation correction measures. Preheating before welding and post-weld heat treatment must be performed according to standard requirements to eliminate hardened structures or reduce residual stress. The welding environment (wind speed, humidity, temperature) should meet standard limits to prevent environmentally induced defects such as porosity and hydrogen-induced cracking.
Inspection and acceptance standards are applied throughout the quality assessment after welding completion. Non-destructive testing (NDT) methods, such as radiographic, ultrasonic, magnetic particle, and penetrant testing, are used to determine the acceptability of internal and surface defects according to standards such as GB/T 3323 and JB/T 4730. Mechanical property tests (tensile, bending, impact) and macroscopic acid etching tests verify the joint strength and ductility. Acceptance levels are classified according to product application, with the most stringent acceptance criteria applied to high-risk areas such as pressure equipment and aerospace structures.
Record keeping and traceability are closed-loop requirements for standard implementation. Welding procedure qualification reports, welder qualifications, material certificates, welding records, and test reports should be fully archived to ensure that any step can be reviewed retrospectively, providing a basis for quality improvement and incident analysis.
In general, welding execution standards serve as the legally mandated technical language and code of conduct for the entire welding process. They provide clear guidance for operators and establish objective criteria for quality supervision and third-party certification. Only by internalizing these standards into every stage of design and production can we minimize defect risks, ensure the safety, durability, and reliability of welded structures, and lay a solid quality foundation for high-end manufacturing and major engineering projects.
