This standard specifies the method for ultrasonic testing with angle probe contact method and Gradeification for the steel grid structure, the welding joints of round tubes, and the tubular joints of steel tube with butt welds. At the same time, it also specifies the ultrasonic testing for the building steel structures including such plate joints as steel roof truss lattice column (beam) steel member, steel rigid frame, crane beam, welded H-shaped steel, box-type steel framework column, beam, truss or welded built-up member in frame girder and structures of steel buildings, as well as the Gradeification method according to the ultrasonic testing result.
This standard is applicable to ultrasonic testing and Gratification for the welded hollow sphere branch pipes and bulb welding joints that the wall thickness of base material is 4mm, corm is no less than 120mm and pipe diameter is no less than 60mm; the welding joints of bolt-speric jointed member bars and conehead or sealing plates that the wall thickness of base material is no less than 3.5mm and the pipe diameter is no less than 48mm; and the carbon structure steel and low-alloy high-tensile structural steel welding joints of round tubes that the pipe diameter of its branch tube is no less than 89mm, wall thickness is 6mm, partial dihedral angle is no less than 30°, and the ratio between the wall thickness and outside diameter of branch tube is less than 13%. It is also applicable to the testing for the welding joints of steel castings, austenite bulbs and joints as well as the butt joints of round tube or welds of welded tubes.
This standard is also applicable to the double-transducer ultrasonic testing for such welding joints as the full-penetrating butt joints of carbon structure steel low-alloy high-tensile structural steel plates that the thickness of its base material is no less than 4mm, the electroslag welded joints of box-type elements, T-joints, and the overlapping and corner joints, as well as the plates, forgings and steel castings for steel structure. It also is applicable to the testing for the joints of square rectangular tube, structural steel tubular pile in subsurface construction, welding joints on endplates of pretensioned prestressing tubular pile as well as the circumferential welds with curvature radius being no less than 1000mm and the longitudinal welds with curvature radius being no less than 1500mm on the plate shell structure. The ultrasonic testing and Gratification for the welding joints of bridge engineering and hydro-technical metal constructions may be executed by referring to this standard.
