This standard specifies the rules, test methods and acceptance criteria of welding procedure qualification carried out before the production, installation and overhaul of steel equipment such as boilers, pressure vessels, pipelines and steel structures in the power industry.
This standard is applicable to the welding procedure qualification of welding methods such as shielded metal arc welding (SMAW), argon-shielded tungsten arc welding (GTAW), gas metal arc welding/flux cored arc welding (GMAW/FCAW), oxygen fuel gas welding (OFW) and submerged arc welding (SAW).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 150.2 Pressure vessels - Part 2: Materials
GB/T 228.1 Metallic materials - Tensile testing - Part 1: Method of test at room temperature
GB/T 229 Metallic materials - Charpy pendulum impact test method
GB/T 700 Carbon structural steels
GB/T 711 Hot-rolled quality carbon structural steel plates, sheets and wide strips
GB 713 Steel plates for boilers and pressure vessels
GB/T 983 Stainless steel covered electrodes
GB/T 1220 Stainless steel bars
GB/T 1221 Heat-resistant steel bar
GB/T 1591 High strength low alloy structural steels
GB/T 1954 Methods of measurement for ferrite content in austenitic Cr-Ni stainless steel weld metals
GB/T 2650 Impact test methods on welded joints
GB/T 2651 Tensile test method on welded joints
GB/T 2653 Bend test methods on welded joints
GB/T 2654 Methods of hardness tests for welded joint and surfacing metal
GB/T 3077 Alloy structure steels
GB 3087 Seamless steel tubes for low and medium pressure boiler
GB/T 3274 Hot-rolled plates and strips of carbon structural steels and high strength low alloy structural steels
GB/T 3280 Cold rolled stainless steel plate, sheet and strip
GB/T 3323 Radiographic examination of fusion welded joints in metallic materials
GB 3531 Low alloy steel plates for low temperature pressure vessels
GB/T 4237 Hot rolled stainless steel plate, sheet and strip
GB/T 4334.5 Corrosion of metals and alloys - Test methods for intergranular corrosion of stainless steels
GB/T 5117 Covered electrodes for manual metal arc welding of non-alloy and fine grain steels
GB/T 5118 Covered electrodes for manual metal arc welding of creep-resisting steels
GB/T 5293 Carbon steel electrodes and fluxes for submerged arc welding
GB 5310 Seamless steel tubes and pipes for high pressure boiler
GB/T 8110 Welding electrodes and rods for gas shielding arc welding of carbon and low alloy steel
GB/T 8165 Stainless steel clad plates sheets and strips
GB/T 9711 Petroleum and natural gas industries - Steel pipe for pipeline transportation systems
GB/T 10045 Carbon steel flux cored electrodes for arc welding
GB/T 12470 Low-alloy steel electrodes and fluxes for submerged arc welding
GB/T 16270 High strength structural steel plates in the quenched and tempered condition
GB/T 17493 Low alloy steel flux cored electrodes for arc welding
GB/T 17854 Stainless steel electrodes and fluxes for submerged arc welding
GB 19189 Quenched and tempered high strength steel plates for pressure vessels
GB/T 20878 Stainless and heat-resisting steels - Designation and chemical composition
GB 24511 Stainless steel plate, sheet and strip for pressure equipment
DL/T 330 Ultrasonic time of flight diffraction technique in welded joints of hydroelectric or hydraulic engineering metal structure and equipment
DL/T 678-2013 General welding procedure specification for structural steel for electric power
DL/T 679 Code for welder technical qualification
DL/T 752 The code of the welding on dissimilar steel for power plant
DL/T 819 The code for the welding heat treatment for power plant
DL/T 820 The code of ultrasonic inspection section for butt welds of pipes
DL/T 821 The code of radiographic examination of butt welded-joints of pressure steels pipes and tubes
DL/T 869-2012 The code of welding for power plant
DL/T 884 Power plant metallography inspection and assessment guideline
NB/T 47002.1 Explosion welded clad plate for pressure vessels - Part 1: Stainless steel-steel clad plate
NB/T 47008 Carbon steel and alloy steel forgings for pressure equipment
NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment
JB/T 4730.2 Nondestructive testing of pressure equipment - Radiographic testing
JB/T 4730.3 Nondestructive testing of pressure equipment - Ultrasonic testing
JB/T 10087 Specifications for steel casting of steam turbines for pressure purposes
3 Terms and definitions
For the purpose of this standard, the following terms and definitions apply.
3.1
welding procedure qualification
evaluation on test process carried out to verify the correctness of the proposed welding process of welding piece and on the results
3.2
welding procedure qualification record; PQR
documents recording relevant test data and results during welding process qualification
3.3
welding procedure specification; WPS
welding procedure documents (or welding procedure instructions) guiding the welding of products which is developed in combination with the product technical requirements and site conditions according to the qualified welding procedure qualification report
3.4
welding piece
components made by welding
3.5
test piece
welding piece used for welding procedure qualification test, which is made according to a predetermined welding procedure and includes two parts, namely base metal and welded joint
3.6
test specimen
standard or non-standard samples prepared for testing according to relevant standards
4 General
4.1 The welding unit shall have such welding procedure qualification report or welding procedure reliability evaluation report as consistent with the welding project.
4.2 Welding procedure qualification works shall be based on the weldability evaluation of the steel. The weldability evaluation data required for welding procedure qualification shall be provided by the steel supplier or collected by the construction unit.
4.3 The steels and welding materials used for welding procedure qualification shall have material quality certificates and meet the corresponding standards. If the authenticity of the material quality certificates cannot be determined or there are doubts about the material performance and chemical composition, re-inspection shall be conducted.
4.4 The welding equipment and tools used in the welding procedure qualification shall be in a normal state, and the instruments and gas flow meters used for parameter recording shall be calibrated.
4.5 The acceptance criteria of the welding procedure qualification test shall meet the requirements of the product technical specifications. If no acceptance criteria are specified in the product technical specifications, the acceptance criteria shall be as specified in this standard or relevant standards.
4.6 The personnel who is in charge of the welding procedure qualification works and comprehensively evaluate the welding and test results shall have the qualification of welding engineer. Welding of test pieces shall be performed by the welding personnel familiar with operation skills of the unit using the equipment of the unit. The inspection of test pieces and the test personnel shall meet the relevant requirements of DL/T 869.
4.7 The welding procedure qualification data shall be filed and saved.
4.8 The welding procedure qualification data after examination and approval is applicable within the same quality management system.
