5.2 Welding Work
Ⅰ Dominant Items
5.2.1 The matching between parent metal and welding rods，welding wires，welding flux or other welding materials shall be in conformity with the design requirements and the related requirements specified in the current national industrial standard of the Technical specification for welding of steel structure of building（JGJ 81-2002）.The welding rods，welding flux，flux cored wire and other welding materials shall be baked and stored according to the corresponding instructionsand welding process documents respectively before using.
Quantity for inspection:one hundred percent；
Inspection method:check the related quality certificates and baking records.
5.2.2 Any welder undertaking the welding must have passed the related examination and gained the related qualification certificate.Any welder holding qualification certificate must undertake only the welding operation（s）within the scope of his qualification.
Quantity for inspection:one hundred percent；
Inspection method:Check conformity certificate of welder，the approved scope and valid period.
5.2.3 For the steel materials，welding materials，welding methods，heat treatments after welding，and etc，adopted for the first time，the construction organization shall carry out process assessments for them，and determine the welding processes for them respectively depending on the corresponding assessment reports.
Quantity for inspection:one hundred percent；
Inspection method:check the assessment reports of welding process.
5.2.4 For the GradeⅡwelding seams with full penetration according to the design requirements，the inner flaws shall be detected by ultrasonic flaw detection；and the inner flaws may be detected by ray flaw detection when they can't be determined by ultrasonic flaw detection.The inner flaws of such welding seams shall be graded and detected according to the current national standard of Non-destructive testing of welds-Ultrasonic testing-Techniques，testing levels，and assessment（GB/T 11345）or according to the current national standard of Methods for radiographic inspection and classification of radiographs for fusion welded butt joints in steel（GB 3323）.
The quality grades of the GradeⅡwelding seamsand the classification of flaws shall be in conformity with the Table 5.2.4.
Quantity for inspection:one hundred percent；
Inspection method:check the records of ultrasonic detection or the records of ray flaw detection.
Table 5.2.4 Quality grades of the GradeⅡwelding seams and the classification of flaws
Note:The testing proportion shall be calculated according to the following principles:（1）For the welding seams performed in factory，the testing proportion shall be calculated for every welding seam；and the testing length shall be more than 200mm；and when the welding seam is less than 200mm，the whole seam shall be tested；（2）For the welding seams performed onsite during installation，the Testing proportion shall be calculated for every type of welding seams performed under same conditions；and the detection length shall be more than 200mm；and the seam accepted detection shall be more than one.
5.2.5 In the surface of welding seam，there shan't be any crack，or welding beading，or other defect.In the welding seam of the gradeⅡ，there shan't be any air cavity，Slag inclusion，crater crack，arc-caused fray and other similar defect.
Quantity for inspection:inspect randomly 10% of the total for every batch of elements of every type，but not less than 3；and inspect 5% of the total for every type of welding seams in the elements inspected，but not less than one；and inspect one point for every seam inspected，ensuring that the total of the points examined/detected during inspection are more than 10 points.
Inspection method:examine by eyes or hand lens or welding-seam gauges or steel rulers.When any flaw can't be determined，detect via permeation flaw detection or magnetic particle inspection.
Ⅱ General Items
5.2.6 The appearance quality of GradeⅡ，GradeⅢwelding seams shall be in conformity with the Code for acceptance of construction quality of steel structures（GB 50205-2001）.The appearances of GradeⅢbuttjointed seams shall be inspected in accordance with the requirements stated for the GradeⅡseams.
Quantity for inspection:inspect randomly 10% of the total for every batch of elements of every type，but not less than 3；and inspect 5% of the total for every type of welding seams in the elements inspected，but not less than one；and inspect one point for every seam inspected，ensuring that the total of the points examined/detected during inspection are more than 10 points.
Inspection method:examine by eyes or hand lens or welding-seam gauges or steel rulers.
5.2.7 The allowable variations for sizes of welding seam shall be in conformity with the Code for acceptance of construction quality of steel structures（GB 50205-2001）.
Quantity for inspection:inspect randomly 10% of the total for every batch of elements of every type，but not less than 3；and inspect 5% of the total for every type of welding seams in the elements inspected，but not less than one；and inspect one point for every seam inspected，ensuring that the total of the points examined/detected during inspection are more than 10 points.
Inspection method:examine with welding-seam gauges.
5.2.8 The appearance of any welding seam shall be able to meet the following requirements:
a.Even；b.Good formation；c.Smooth transition between welding beads，and between welding bead and base metal；d.No welding slag，basically.
Quantity for inspection:inspect randomly 10% of the total for every batch of elements of every type，but not less than 3；and inspect 5% of the total for every type of welding seams in the elements inspected，ensuring that the total of the points examined/detected during inspection are more than 5 points.
Inspection method:examine by eye observation.