NB/T 20002.4-2013 Welding code for mechanical components of PWR nuclear islands - Part 4: Qualification of filler materials
1 Scope
This part specifies requirements of qualification tests performed on filler materials for fabrication and installation of mechanical components of PWR nuclear islands.
This part is applicable to qualification of filler materials for carbon steel, low alloy steel, austenitic stainless steel, nickel-base alloy welding and cladding. These filler materials comprise: covered electrode, flux cored electrode and flux (relevant to welding wire or strip electrode of given chemical component).
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/T 25775 Technical delivery conditions for welding consumables - Type of product dimensions tolerances and markings (GB/T 25775- 2010, ISO544: 2003, MOD)
NB/T 20002.2 Welding code for mechanical components of PWR nuclear islands - Part 2: Acceptance for welding filler materials
NB/T 20002.3 Welding code for mechanical components of PWR nuclear islands - Part 3: Welding procedure qualification
NB/T 20009.1 Welding material for pressurized water reactor nuclear power plants - Part 1: Carbon steel covered electrodes for class 1, 2, 3 components
NB/T 20009.2 Welding material for pressurized nuclear power plants - Part 2: Low alloy steel covered electrodes for class 1,2,3 components
NB/T 20009.3 Welding material for pressurized nuclear power plants - Part 3: Stainless steel covered electrodes for class 1,2,3 components
NB/T 20009.4 Welding material for pressurized nuclear power plants - Part 4: Nickel-based alloy covered electrodes for class 1,2,3 components
NB/T 20009.5 Welding material for pressurized nuclear power plants - Part 5: Carbon steel flux cored electrodes for gas shielded arc welding of class 1,2,3 components
3 General
3.1 The qualification test performed on filler material aims to qualification of trade designation.
3.2 Qualification tests on filler materials comprise the following:
——tests on filler materials (as delivered);
——deposited metal test: the number of lots of products and the number of test welds shall be sufficient (5 lots at least, the number shall be determined in case of new products) to substantiate the characteristics guaranteed by the supplier of filler materials;
——welding joint test on standard test coupon.
3.3 Tests on filler materials (as delivered) and deposited metal tests shall be carried out by the supplier of filler materials. Based on test result, the supplier shall prepare deposited metal qualification data sheet (The content of the data sheet according to the requirements given in 6.2) for each designation of evaluated material.
3.4 The welding joint qualification test on standard test coupon shall be carried out by the equipment manufacturer. However, in case that the welding procedure qualification test carried out by equipment manufacturer covers the welding joint qualification test, it may render the unnecessary test on standard test coupon.
3.5 The filler materials used for qualification test shall be manufactured under the condition of mass production. The manufacture condition shall meet the requirement of definition of lot given in NB/T 20002.2 so as to ensure the homogeneity of each lot.
3.6 The variables leading to the change of lot number include the following:
a) geometrical dimension of filler materials;
b) heat number used for the filler materials (core wire, welding wire and strip electrode);
c) lot number of flux or electrode coating determined by filler materials manufacturer based on manufacturing condition of various component material and mixture.
3.7 The filler materials intended for qualification test shall be taken from the lots mentioned above.
4 Limits of validity of qualification
4.1 Basic rule
Foreword i 1 Scope 2 Normative references 3 General 4 Limits of validity of qualification 5 Implementation of qualification tests 6 Qualification report
