The steel structure used for grid processing is a structural form that bears load transfer by connecting steel plates with hot-rolled, cold-formed or welded profiles (such as I-shaped steel profiled steel plates) The construction steel structure industry can be further divided into heavy steel, space steel, light steel, and other fields through connectors (bolts, high-strength bolts, etc.). Steel structures have been widely used in the construction industry abroad. Small high-rise steel structures are very common in developed countries. In recent years, steel structures have been applied in China due to their advantages of earthquake resistance, wind resistance, durability, environmental protection, and speed. In the late 1990s, with the development of the civil economy and the leapfrog development of the steel industry, internal steel structure enterprises learned and absorbed advanced external concepts and technologies, introduced advanced processing and installation equipment, and the overall technical level was close to that of similar foreign enterprises. The steel structure industry showed an unprecedented prosperity. So what are its specific advantages that make its development prospects so broad? This is because the steel structure of the grid structure has a novel and unique shape, diverse structural systems, complex node structures, and various forms of welded nodes. The difficulty of on-site production, installation, and welding technology is increasing.

There are many types and specifications of steel used, and more and more low alloy high-strength structural steel and thick steel are being used. With the continuous improvement of steel production technology, the application of cast steel, austenitic stainless steel, and composite steel plates is also increasing. Therefore, before on-site construction, real-time weldability tests of new steel grades should be conducted based on the delivery status of the steel used, exploring scientific welding process parameters and formulating corresponding welding process measures. There are many connection factors between factory production and on-site installation, and there are many cross operations among different professions, making on-site installation difficult.

The building has a high height and a large structural span. The main parts of the structure are the joint welds between the frame beams and columns, the joint welds between the shear plates and columns, the joint welds between the beam belly and columns, and the joint welds between columns, which are basically the first level welds with groove penetration. Ultrasonic testing requires high welding quality.