Welding Specifications
In order to ensure the welding of steel structures meets the standards and specifications set by JGJ 81-2002, special welding specifications must be followed. Welding specifications for steel structures include the preparation of welder qualification test, the architectural design of welded joints and the selection of welding procedures and materials. The Code for Design of Steel Structures (JGJ 81-2002) prescribes the welding specifications for steel structures. This article will discuss these welding specifications in details.
Welder Qualification Tests
Welder qualification tests are necessary for ensuring that welders are obtaining the highest level of quality when welding steel structures. There are three types of tests used to measure the skill levels of a welder in accordance with JGJ 81-2002: qualification tests, examinations of theoretical basis and practical skills tests. The qualification tests assess the welders’ knowledge of welding and welded joint design, while the examinations of theoretical basis tests assess the welders understanding of welding and the ability to implement welding procedures. And the practical skills tests assess the welders’ ability to weld under actual welding condition and to identify their welding defects.
Architectural Design of Welded Joints
The architectural design of welded joints is essential for the structural integrity of steel structures. JGJ 81-2002 stipulates that welded joints should meet the national standard requirements for welded joints. This includes specifying the location, distribution and depth of welds, as well as the specific welding techniques to be used for different types of joints. For example, a full penetration fillet weld should be used for most applications, while a double-fillet weld should be used for joints with the same thickness of material.
Selection of Welding Procedures and Materials
The selection of welding procedures and materials requires expertise and knowledge of welding in order to ensure that steel structures meet the necessary weldability and structural strength requirements. JGJ 81-2002 defines welding procedure and materials specifications, including arc welding and submerged arc welding. Arc welding is a fusion welding process using an electric current to create an electric arc that is used to melt and weld metals. Submerged arc welding is a fusion welding process in which the molten weld and base materials are protected from the atmosphere by a blanket of granular flux.
Conclusion
JGJ 81-2002 contains welding specifications which are essential for ensuring the welding of steel structures meets the standards and specifications set by this code. Welder qualification tests are necessary for ensuring welders possess the necessary skillset and knowledge to perform their duties effectively and safely. Architectural design of welded joints is important for ensuring the structural integrity of steel structures, and the selection of welding procedures and materials is essential for meeting necessary weldability and structural strength requirements.
