Detail of NB/T 47008-2017

Introduction of NB/T 47008-2017

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 standard is developed according to the rules given in GB/T 1.1-2009 Directives for Standardization - Part 1: Structure and Drafting of Standards. This standard incorporates relevant content of JB/T 9626-1999 Specification for Bolier Forging, replaces NB/T 47008-2010 Carbon and Alloy Steel Forgings for Pressure Equipments and has the following main technical changes with respect to NB/T 47008-2010: ——5 steel forging designations including 12CrMo, 30CrMo, 10Cr9MoW2VNbBN, 09CrCuSb, 08Cr2AlMo and 2 steel forging designations for ultrahigh pressure vessel including 35CrNi3MoV, 36CrNi3MoV are added; ——The contents on design pressure and temperature are cancelled from Scope; ——Relevant requirements of order contents are refined; ——Requirements on macroscopic inspection are added; ——Requirements on metallographic inspection are added; ——The quality grade for steel forging ultrasonic testing is increased; ——Requirements on hydrogen induced cracking (HIC) test are added; ——The criteria permissible for soldering are modified; ——6 designations of forgings for matched valve and special component including 25, 25Cr2MoV, 25Cr2Mo1V, 20Cr1Mo1VNbTiB, 20Cr1Mo1VTiB and 38CrMoAl are added; ——High-temperature mechanical property table for common forging steel is added. Annex A and Annex C are informative while Annex B is normative. This standard was proposed by and under the jurisdiction of the China Standardization Committee on Boilers and Pressure Vessels (SAC/TC 262). The previous editions of the standard replaced by this standard are as follows: ——JB 4726-1994; ——JB/T 9626-1999; ——JB 4726-2000; ——NB/T 47008-2010. Carbon and Alloy Steel Forgings for Pressure Equipment 1 Scope This standard specifies terms and definitions, order contents, technical requirements, test methods, inspection rules as well as marking and quality certificate of carbon steel and alloy steel forgings for pressure equipment. 2 Normative References The following documents for the application of this document are essential. For dated reference, only the edition cited applies. For undated reference, its latest edition (including any amendments) applies. GB/T 222 Permissible Tolerances for Chemical Composition of Steel Products GB/T 223 Methods for Chemical Analysis of Iron, Steel and Alloy (Applicable Parts) GB/T 226 Test Method for Macrostructure and Defect of Steel by Etching GB/T 228.1 Metallic Materials - Tensile Testing - Part 1: Method of Test at Room Temperature GB/T 228.2 Metallic Materials - Tensile testing - Part 2: Method of Test at Elevated Temperature GB/T 229 Metallic Materials - Charpy Pendulum Impact Test Method GB/T 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method GB/T 4336 Carbon and Low-alloy Steel - Determination of Multi-element Contents - Spark Discharge Atomic Emission Spectrometric Method (Routine Method) GB/T 6394 Metal-methods for Estimating the Average Grain Size GB/T 8650 Evaluation of Pipeline and Pressure Vessel Steels for Resistance to Hydrogen-Induced Cracking GB/T 10561 Steel-Determination of Content of Nonmetallic Inclusions-Micrographic Method Using Standards Diagrams GB/T 13298 Inspection Methods of Microstructure for Metals GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition GB/T 20123 Steel and Iron - Determination of Total Carbon and Sulfur Content Infrared Absorption Method after Combustion in an Induction Furnace (Routine Method) GB/T 20124 Steel and Iron - Determination of Nitrogen Content - Thermal Conductimetric Method after Fusion in a Current of Inert Gas (Routine Method) NB/T 47013.3 Nondestructive Testing of Pressure Equipments - Part 3: Ultrasonic Testing NB/T 47013.4 Nondestructive testing of pressure Equipments - Part 4: Magnetic Particle Testing NB/T 47013.5 Nondestructive Testing of Pressure Equipments - Part 5: Penetrant Testing 3 Terms and Definitions 3.1 hollow forging the axisymmetric hollow forging with axial length L greater than outside diameter D, as shown in Figure 1a); t refers to nominal thickness 3.2 ring forging the axisymmetric hollow forging with axial length L less than or equal to outside diameter D, as shown in Figure 1b); L or t, whichever is smaller, refers to nominal thickness 3.3 disk forging the axisymmetric solid forging with axial length L less than or equal to outside diameter D, as shown in Figure 1c); L refers to nominal thickness 3.4 bowl forging the axisymmetric forging with axial length H less than or equal to outside diameter D and with concave section, as shown in Figure 1d); t1 or t2, whichever is larger, refers to nominal thickness 3.5 neck flange forging the axisymmetric hollow forging with two outside diameters in axial direction, as shown in Figure 1e); t1 or t2, whichever is larger, refers to nominal thickness 3.6 bar forging the solid forging with axial length L greater than outside diameter D and with circular section, as shown in Figure 1f); D refers to nominal thickness the forging with length L greater than two side lengths a and b and with rectangular section, as shown in Figure 1g); a or b, whichever is smaller, refers to nominal thickness a) Hollow forging b) Ring forging c) Disk forging d) Bowl forging e) Neck flange forging f) Bar forging (circular section) g) Bar forging (rectangular section) Figure 1 Forging Shape 4 Order Contents The order contract by reference to this standard shall include the following contents: a) Product name; b) Order drawing; c) Standard No.; d) Material designation; e) Forging grade; f) Quantity (or quality); g) Delivery state (including heat treatment and surface requirements); h) Non-destructive testing requirements; i) Additional technical requirements. 5 Technical Requirements 5.1 Smelting method Steel for forgings shall be killed steel subject to electric furnace or oxygen converter smelting and external refining, for which electroslag remelting and other smelting method shall be adopted through negotiation between the supplier and the purchaser. 5.2 Chemical composition 5.2.1 Melting analysis 5.2.1.1 Designation and chemical composition of steel for forgings (melting analysis) shall meet the requirements of Table 1. 5.2.1.2 Designation and chemical composition of steel for matched valve and special component forgings may refer to Annex A. 5.2.1.3 As required by the purchaser and indicated in the contract, P and S contents of 35# steel in Table 1 may be: P≤0.025% and S≤0.015%. 5.2.2 Product analysis 5.2.2.1 The purchaser may perform product analysis and permissible deviation between corresponding analysis result and specified value in Table 1 shall meet the requirements of GB/T 222. 5.2.2.2 For designations with P≤0.020% in Table 1, permissible positive deviation for phosphorus content in product analysis is 0.003%; for designations with S≤0.010% in Table 1, permissible positive deviation for sulfur content in product analysis is 0.002%.

Contents of NB/T 47008-2017

Foreword i 1 Scope 2 Normative References 3 Terms and Definitions 4 Order Contents 5 Technical Requirements 6 Test Methods 7 Inspection Rules 8 Marking and Quality Certificate Annex A (Informative) Forgings for Matched Valves and Special Components of Boiler Annex B (Normative) Additional Requirements Annex C (Informative) High-temperature Mechanical Properties