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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 and replaces NB/T 47010-2010 Stainless and Heat-resisting Steel Forgings for Pressure Equipments; the following main technical changes have been made with respect to NB/T 47008-2010:
――11 designations of steel forging including S11348, S30453, S30458, S32169, S34778, S31653, S31658, S31252, S25073, S25554 and S23043 and designation of steel forging for ultrahigh pressure vessel including S51740 are added;
――The contents on design pressure are deleted from Scope;
——Relevant requirements of order contents are refined;
――Requirements on macroscopic inspection are added;
――Requirements on metallographic inspection are added in allusion to steel forging and duplex steel forgings for boiler pressure components;
——The quality grade for steel forging ultrasonic testing is added;
——The criteria permissible for welding repair are modified;
――3 designations of steel forgings for matched valve and special component including S32590, S42020 and S42030 are added;
——High temperature mechanical property table for common forging steel is added.
Annex A and Annex C of this standard are informative while Annex B is normative.
This standard was proposed by and is 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 4728-1994;
——JB /T 9626-1999;
——JB 4728-2000;
——NB/T 47010-2010.
Stainless and Heat-resisting 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 stainless and heat-resisting 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 231.1 Metallic Materials - Brinell Hardness Test - Part 1: Test Method
GB/T 6394 Metal-methods for Estimating the Average Grain Size
GB/T 10561 Steel-Determination of Content of Nonmetallic Inclusions-Micrographic Method Using Standards Diagrams
GB/T 11170 Stainless Steel - Determination of Multi-element Contents - Spark Discharge Atomic Emission Spectrometric Method (Routine Method)
GB/T 13298 Inspection Methods of Microstructure for Metals
GB/T 13305 Micrographic Method for Determining Area Content of the α-phases in Stainless Steels
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 47013.5 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
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