Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This is Section 4 of NB/T 47018 under the general title Specification of welding materials for pressure equipment: The following parts of NB/T 47018 have been issued:
——Section 1: General rule;
——Section 2: Electrodes for steel;
——Section 3: Steel electrodes and rods for gas shielded arc welding;
——Section 4: Electrodes and fluxes for submerged arc welding;
——Section 5: Stainless steel strip electrodes and fluxes for overlay welding;
——Section 6: Bare aluminum and aluminum-alloy welding electrodes and rods;
——Section 7: Titanium and titanium-alloy welding electrodes and rods.
This document replaces NB/T 47018.4-2017 Technical permission of welding materials for pressure equipment - Section 4: Electrodes and fluxes for submerged arc welding. In addition to structural adjustment and editorial changes, the following main technical changes have been made with respect to NB/T 47018.4-2017:
a) In the clause “Normative references”, the original GB/T 5293 Carbon steel electrodes and fluxes for submerged arc welding was renamed as Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels - Classification, the original GB/T 12470 Low-alloy steel electrodes and fluxes for submerged arc welding was renamed as Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of creep-resisting steels - Classification, the original GB/T 17854 Stainless steel electrodes and fluxes for submerged arc welding was renamed as Solid wire electrodes/flux combinations for submerged arc welding of stainless steels - Classification, and GB/T 36034 Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of high strength steels - Classification and GB/T 36037 Fluxes for submerged arc welding and electroslag welding are added (see Clause 2);
b) The content that shall be included in the quality certificate has been modified [see b) in 3.1.2; b) in 3.1.2 of Edition 2017];
c) The specific requirements for the interchangeability between the batch numbers of fluxes and electrodes in the quality certificate of welding materials have been modified (see 3.1.3 and 3.1.4; 3.1.3 of Edition 2017);
d) The classification codes of electrode/flux combinations have been modified (see Tables 1, 2 and 4; Tables 1, 2 and 4 of Edition 2017);
e) F4××-H××× (original combination) in the classification of solid electrode/flux combinations for non alloy and fine grain steels has been modified to S 43× ×××-SU×××, and the lower limit of tensile strength of deposited metal has been adjusted accordingly from 415 MPa to 430 MPa; F48××-H××× (original combination) has been modified to S 49× ×××-SU×××, and the lower limit of tensile strength of deposited metal has been adjusted accordingly from 480 MPa to 490 MPa; the combination “S 57× × ××-SU×××” has been added (see Tables 1 and 2; Tables 1 and 2 of Edition 2017);
f) In the classification of electrode/flux combinations for creep-resisting steels, F48××-H××× (original combination) has been modified to S 49× × ××-SU×××, and the lower limit of tensile strength of deposited metal has been modified accordingly from 480 MPa to 490 MPa (see Tables 1 and 2; Tables 1 and 2 of Edition 2017);
g) S 59× × ××-SU××× and S 69× × ××-SU××× have been added in the classification of electrode/flux combinations for high strength steels (see Tables 1 and 2; Tables 1 and 2 of Edition 2017);
h) S F309L ××-S309L, S F309LMo ××-S309LMo, S F312 ××-S312, S F16-8-2 ××-S16-8-2, S F317L ××-S317L, S F347L ××-S347L, S F385 ××-S385, S F2209 ××-S2209, and S F2594 ××-S2594 have been added in the classification of electrode/flux combinations for stainless steels (see Tables 1 and 2; Tables 1 and 2 of Edition 2017);
i) The comparison between the classification of solid electrode/flux combinations for submerged arc welding and the flux model in Edition 2017 has been added (see Annex A);
j) The qualified indexes for the contents of P and S and the impact absorbed energy of deposited metal have been improved to some extent, and the qualified index for the impact absorbed energy of deposited metal of welding materials for submerged arc welding of boilers has been reduced to some extent and the impact test temperature has been increased by 20℃ (see Table 2 and 3.6.3; Table 2 of Edition 2017);
k) The requirement for post-weld heat treatment of deposited metal has been added (see 3.5);
l) The requirement for percentage elongation after fracture of deposited metal of duplex stainless steel has been added (see 3.6.2);
m) The requirement that the deposited metal can be exempted from batch-by-batch determination of content of diffusible hydrogen has been added (see 3.7).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by and is under the jurisdiction of SAC/TC 262 National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China.
The previous editions of this document are as follows:
——NB/T 47018.4-2011;
——NB/T 47018.4-2017;
——This is the second revision.
Specification of welding materials for pressure equipment - Section 4: Electrodes and fluxes for submerged arc welding
1 Scope
This document specifies the technical requirements, test methods and product marking for electrodes, fluxes and electrode/flux combinations for submerged arc welding.
This document is applicable to solid wire electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels, creep-resisting steels, high strength steels and stainless steels for pressure equipment.
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions 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 2653 Bend test methods on welded joints
GB/T 3965 Determination of diffusible hydrogen in deposited metal
GB/T 5293 Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of non alloy and fine grain steels - Classification
GB/T 12470 Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of creep-resisting steels - Classification
GB/T 17854 Solid wire electrodes/flux combinations for submerged arc welding of stainless steels - Classification
GB/T 29713 Wire electrodes, strip electrodes, wires and rods for arc welding of stainless and heat resisting steels
GB/T 36034 Solid wire electrodes, tubular cored electrodes and electrode/flux combinations for submerged arc welding of high strength steels - Classification
GB/T 36037 Fluxes for submerged arc welding and electroslag welding
NB/T 47013.2 Nondestructive testing of pressure equipment - Part 2: Radiographic testing
NB/T 47013.11 Nondestructive testing of pressure equipment - Part 11: Standard practice for X-ray digital radiography
NB/T 47014 Welding procedure qualification for pressure equipment
NB/T 47018.1 Technical permission of welding materials for pressure equipment - Part 1: General rule
3 Technical requirements
3.1 General requirements
3.1.1 The electrodes and fluxes for submerged arc welding of non alloy and fine grain steels, creep-resisting steels, high strength steels and stainless steels for pressure equipment shall not only meet the requirements of GB/T 5293, GB/T 12470, GB/T 17854, GB/T 36034, GB/T 36037 and GB/T 29713 respectively, but also meet those specified in NB/T 47018.1 and this document.
3.1.2 The quality certificate of welding materials for submerged arc welding of pressure equipment shall cover the following contents:
a) batch numbers of flux and electrode matched with the flux, as well as the inspection results of electrode inspection and flux inspection as well as inspection of deposited metal after matching and welding;
b) contents of the impurity elements S and P in fluxes for non alloy and fine grain steels, creep-resisting steels, high strength steels and stainless steels; and metallurgical property codes shall be indicated.
3.1.3 For such welding materials as creep-resisting steels with standard tensile strength of deposited metal not less than 620 MPa, fine grain steels with standard impact test temperature lower than -70℃, and high strength steels with standard impact test temperature lower than -20%℃ or steels required by the purchaser, the batch numbers of electrodes and fluxes for submerged arc welding shall be the same as those in the quality certificate conforming to 3.1.2. In addition, the batch numbers of the same type of electrodes and fluxes supplied by the same welding material manufacturer can be interchanged, which shall be indicated in the quality certificate.
3.1.4 If the batch number of electrodes and/or fluxes is different from that in the quality guarantee and does not meet those specified in 3.1.3, the ordering unit shall inspect such electrodes and/or fluxes according to the requirements of the quality assurance system, and the technical requirements shall not be inferior to those specified in this document. Only after passing the inspection can such electrodes and/or fluxes be used for welding pressure equipment.
3.1.5 The electrodes and fluxes for submerged arc welding should be selected from the same welding material manufacturer.
Foreword i
1 Scope
2 Normative references
3 Technical requirements
4 Test methods
5 Product identification
Annex A (Informative) Comparison between the classification of solid electrode/flux combinations for submerged arc welding and the flux model in Edition 2017
