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NB/T 47018-2017 consists of the following five sections under the general title Technical permission of welding materials for pressure equipment:
——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.
This is Section 1 of NB/T 47018-2017.
This section is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This section is a revision of NB/T 47018.1-2011 Technical permission of welding materials for pressure equipment - Section 1: General rule. The following main technical changes have been made with respect to NB/T 47018.1-2011:
——The general rules are re-prepared according to the requirements of GB/T 25778-2010;
——Specific specifications are given for the use of flux cored electrodes;
——Adjustment is made to the maximum limits per batch for the stainless steel covered electrodes, the carbon steel core wires, welding wires and rods, the low-alloy steel core wires, welding wires and rods, the stainless steel core wires, welding wires and rods, the stainless steel strip electrodes for overlay welding, the fluxes for carbon steel and low-alloy steel, and the fluxes for stainless steel listed in Table 1;
——The requirement that the as-welded condition of the test piece for mechanical property test of deposited metal shall be noted during procurement of welding materials is added;
——The inspection on the water content in welding electrode covering is changed to the inspection on the diffusible hydrogen content in deposited metal;
——Bend test is added to the inspection items in the product quality certificate.
This section was proposed by and is under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262).
The previous edition of this section is as follows:
——NB/T 47018.1-2011.
Technical permission of welding materials for pressure equipment
Section 1: General rule
1 Scope
This section of NB/T 47018-2017 specifies the basic requirements, batch identification, batching rules, quality certificate, re-inspection, and storage and transportation for procurement of welding materials.
This section is applicable to both the supplier and the purchaser of welding materials for pressure equipment, and the detailed rules are prepared according to the procurement requirements.
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 25778 Procurement guidelines for welding consumables
NB/T 47018.2 Technical permission of welding materials for pressure equipment - Section 2: Electrodes for steel
NB/T 47018.3 Technical permission of welding materials for pressure equipment - Section 3: Steel electrodes and rods for gas shielded arc welding
NB/T 47018.4 Technical permission of welding materials for pressure equipment - Section 4: Electrodes and fluxes for submerged arc welding
NB/T 47018.5 Technical permission of welding materials for pressure equipment - Section 5: Stainless steel strip electrodes and fluxes for overlay welding
NB/T 47018.6 Technical permission of welding materials for pressure equipment - Section 6: Bare aluminum and aluminum-alloy welding electrodes and rods
NB/T 47018.7 Technical permission of welding materials for pressure equipment - Section 7: Titanium and titanium-alloy welding electrodes and rods
JB/T 3223 Welding material quality management specifications
3 Basic requirements
3.1 In addition to the requirements of GB/T 25778, the procurement of welding materials for pressure equipment shall also meet the requirements of this section.
3.2 The distributor of welding materials for pressure equipment (hereinafter referred to as the “distributor”) shall be approved by the manufacturer of the welding materials (hereinafter referred to as the “manufacturer”), and the manufacturer shall be responsible for the training and assessment of the distributor.
3.3 The manufacturer or the supplier (including the distributor) shall provide the orderer with the original quality certificate of the welding material, and is allowed to provide a copy of the certificate, which shall be affixed with the official seal of the supplier (including the distributor) and the signature and seal of the transactor.
3.4 The manufacturer shall provide the welding material orderer with the product instructions, including the product characteristics, performance indicators, application scope, storage requirements, and precautions for use.
3.5 In case of the use of the domestic steel, aluminum or titanium welding materials other than those specified in this standard, the following provisions shall be met:
a) For the welding materials of which the corresponding category but no model (or designation) is available in this standard, their technical requirements shall not be inferior to the requirements for the welding materials of the same category as stated in this standard, and the welding performance and engineering test bases shall be available;
b) For the welding materials of which no corresponding category is available in this standard, refer to the technical requirements specified in this standard, and the welding performance and engineering test bases shall be available;
c) For the flux cored electrodes, the technical permission shall be prepared according to the technical requirements specified in NB/T 47018.2. The carbon steel and low-alloy steel flux cored electrodes shall be of basic slag system. The order contract shall include the specific contents and inspection methods for ensuring the composition and filling uniformity of flux core as well as the measures for ensuring diffusible hydrogen content in deposited metal after the vacuum package of flux cored electrode is opened.
3.6 Where foreign welding materials are adopted, the following requirements shall be met:
a) The foreign welding materials selected shall be those that are allowed to be used in accordance with the corresponding foreign specifications of pressure equipment and are provided with engineering practice basis of pressure equipment, with the application scope not exceeding those specified in the corresponding foreign specifications or the application scope of similar domestic welding materials;
b) The technical requirements for welding materials shall not be inferior to the requirements for welding materials of the same category in this standard. For the welding materials of which no corresponding category is available in this standard, refer to the technical requirements of this standard;
c) When the pressure equipment manufacturer selects a foreign welding material for the first time, it shall grasp the welding performance, use conditions and procurement rules of this material.
3.7 When the orderer has additional technical requirements for the welding materials, it shall include them in the order contract and also specify the inspection methods and acceptance criteria.
3.8 The orderer shall include the as-welded condition of the test piece for mechanical property test of deposited metal of the welding materials to be procured in the technical permission. The post-weld heat treatment conditions shall be in accordance with those specified in the corresponding welding material standards, and if they exceed the requirements of these standards, they will be separately agreed.
4 Batch identification
4.1 Solid welding wire, rod, core wire and strip electrode are all identified by furnace No. and shall be made of the material of single furnace No.
4.2 All the wet agitated materials of welding electrode coating and sintered flux and the furnace charge of fused flux shall be identified according to the controlled chemical composition. The wet agitated material (furnace charge) shall be thoroughly tested before and after the wet agitation (before and after the smelting) to prove that all wet agitated materials (or furnace charge) used in one batch of welding materials have equivalent composition. This test shall at least include chemical composition analysis, and the test results shall be in accordance with the range specified by the welding material manufacturer. Both the test procedures and test results shall be well recorded.
