Seventeen – Welding Procedure Qualification
This chapter of GB/T50259-2012, the Technical Procedures for Welding of Steel Structures, provides specific requirements for welding procedure qualification. A welding procedure specification (WPS) that is qualified according to this chapter and is used in the production welding of steel structures shall conform to the relevant requirements of the Code and meet the requirements of welding engineering design. welding procedure qualification (WPQ) may also be referred to as welding procedure qualification test.
I. General Requirements
1.1 Qualification Of Welding Procedure
Welding procedure qualification is to determine the applicability of welding procedures employed in welding steel structures, which is the basis for the implementation and assurance of quality in welding production. Special welding methods, special welding materials, or welding of steel components which shall usually carry out a welding procedure qualification.
1.2 Specific Requirements
1.2.1 Relevant welding procedures shall comply with GB 50243, the Code for Welding of Steel Structures of Buildings.
1.2.2 When establishing a welding procedure, it shall be approved by the welding engineers, welding workers, constructors, and other persons concerned before being put into use.
1.2.3 The welding joint dimension, weld width and reinforcement, welding process and other characteristics, and other welding requirements shall be taken into account to determine the composition of welding procedure qualification, welding parameters, and welding materials.
1.2.4 Welding procedure determination and qualification of welding parameters shall be carried out by qualified welding engineers according to the relevant requirements of the Code.
1.2.5 To determine a welding procedure qualification, it shall be executed by a qualified welder using a welding machine of the same model and equipment as in production welding.
1.2.6 For welding procedures of the same grade in terms of joint forms, the relation between welding controller parameters and welding outputs shall comply with the requirements of the Code. The welding procedure qualification shall comply with the provisions of the relevant standards.
1.2.7 The welding procedure qualification welding process shall be carried out in accordance with the requirements of the Code and shall meet the requirements of engineering design.
1.2.8 Welding materials used in welding procedure qualification shall be identical to those in production welding.
1.2.9 The welding procedure qualification of welds fabricated by welding machines other than welding power sources listed in the Code shall be carried out according to the relevant welding process.
1.2.10 The welding procedure qualification reports of other welding processes shall be submitted to the State Quality Supervision and Testing Center for welding procedure qualification examination and declaration.
1.2.11 Welding procedure tests that do not conform to the Code shall be repaired or replaced until the requirements of the Code are met.
1.2.12 When establishing a welding procedure, the welding engineers shall sign the welding procedure in their own handwriting.
II. Welding Procedure Qualification Tests
2.1 Types Of Tests
2.1.1 Welding procedure qualification tests shall comply with Table 81 and Table 82.
2.1.2 Welding procedure qualification tests shall include macro tests and mechanical property tests.
2.1.3 For construction steels, the macro test can be used for welding procedure qualification. For alloy steels, the mechanical property test shall be carried out in conjunction with the macro test.
2.2 Macro Tests
2.2.1 Macro tests shall comply with the requirements of Table 83 and Table 84.
2.2.2 Macro tests shall be conducted on the weld samples removed from the test specimens or samples.
2.2.3 A visual inspection of the welds shall be carried out in accordance with Table 85.
2.2.4 On the basis of the visual inspection, a complete penetration macro test shall be carried out in accordance with Table 86.
2.2.5 For welds of over than 50 mm in thickness, the macro test shall enable a clear detection of weld defects that penetrate all the layers of the weld.
2.2.6 The macro test shall meet the requirements of Table 87.
2.3 Mechanical Property Tests
2.3.1 Mechanical property tests shall comply with the requirements of Table 88.
2.3.2 Tensile test specimens for welding procedure qualification shall be tested in accordance with GB/T228.
2.3.3 Hardness test specimens for welding procedure qualification shall be tested in accordance with GB/T230.
2.3.4 The mechanical properties of the welds shall meet the relevant requirements of the Code.
III. Welding Procedure Qualification Reports
3.1 A welding procedure qualification report shall be prepared for each welding procedure qualification test.
3.2 The welding procedure qualification report shall include the following information:
a) Components of test: structural steel grade, steel thickness, required welding grade, and welding process;
b) Welding materials and accessories: welding consumables, welding materials and accessories, such as electrodes and flux;
c) Chemical composition of welding materials, if applicable;
d) Results of macro test and results of mechanical property tests;
e) Weld metal composition, tensile strength, and others, if determined;
f) Summary of welding procedure qualification test;
g) Remarks.
IV. Registration
4.1 The welding procedure qualification report shall be signed by the welding engineer and registered in a special file.
4.2 The registered welding engineer shall periodically review the welding procedure qualification report and other relevant documents to ensure their correctness and validity.
V. Performance
5.1 When a welding procedure is used for the production welding of steel structures, the actual welding performance shall meet the requirements of the welding procedure specification.
5.2 If the welding engineer judges that the welding performance does not meet the relevant requirements of the specification, the welding process shall be improved until the requirements of the welding procedure specification are met.
