There have been some significant changes in this standard over JB 4726-2000:
——Design pressure in application scope has been improved to less than 100MPa from not larger than 35MPa;
——Add five steel grades, namely 20MnNiMo, 15NiCuMoNb, 12Cr2Mo1V, 12Cr3MolV and 10Cr9Mo1VNb;
——Degrade phosphorus and sulfur contents of a majority of steel grades;
——Add tensile property index of nominal thickness less than or equal to 100mm for 20Mn and 16Mn steel grades of forgings;
——Improve strength index of 15CrMo and 12CrIMoV steel forgings;
——Improve impact power index of all the steel forgings;
——Describe clearly that the Grade I forgings are only applicable to 20, 35 and 16Mn steel grades of nominal thickness less than or equal to 100mm.
The Appendix A in this standard is normative.
This standard is proposed by and under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262).
Drafting organizations of this standard: Hefei General Machinery Research Institute, China National General Machinery Engineering Corporation, China Special Equipment Inspection and Research Institute, China First Heavy Industries, Anhui Bureau of Quality and Technical Supervision, Shanghai Power Equipment Research Institute, Wuxi flange forging Co,. Ltd and Jiangyin Fangyuan Ringlike Forging& Flange Co., Ltd
Drafting staffs of this standard: Zhang Xiaohu, Qin Xiaozhong, Zhang Yong, Yang Guoyi, Zhang Wenhui, Zhang Rui, Teng Mingde, Ye Jianping, Chen Zhiwei and Zhao Yuanzhong.
National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262) is in the charge of the explanation of this standard.
This part replaces the following editions in turn:
——JB 4726-1994;
——JB 4726-2000.
PROFESSIONAL STANDARD
OF THE PEOPLE'S REPUBLIC OF CHINA
中华人民共和国行业标准
NB/T 47008-2010 (JB/T 4726)
Carbon and Alloy Steel Forgings for Pressure Equipments
承压设备用碳素钢和合金钢锻件
1 Scope
This standard specifies the technical requirements, test methods and inspection rules, etc. for carbon steel and alloy steel forgings for pressure equipments.
This standard is applicable to carbon steel and alloy steel forgings for pressure equipments with a design temperature not less than -20℃ and design pressure below 100Mpa.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, only the dated versions apply to this standard. For undated references, the latest edition of the normative document (include all the amendments) is applicable to this standard.
GB/T 222-2006 Permissible Tolerances for Chemical Composition of Steel Products
GR/T 223 Methods for Chemical Analysis of Iron, Steel and Alloy
GB/T 228 Metallic Materials-Tensile Testing at Ambient Temperature (ISO 6892:1998 (E))
GBIT/229-2007Metallic materials-Charpy pendulum impact test method (ISO 148-1:2006)
GB/T 23 1.1 Metallic Materials-Vickers Hardness Test-Part 1: Test Method (1S0 6506-1:2005)
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-Alloy Steel (Routine Method)
GB/T 4338 Metallic Materials-Tensile Testing at Elevated Temperature (ISO 783:1999)
GB/f 6394 Metal-methods for Estimating the Average Grain Size (ASTM E112:1996)
GB/T 10561 Steel-Determination of Content of Nonmetallic Inclusions-Micrographic Method Using Standards Diagrams (1S0 4967: 1998)
GB/T 20066 Steel and Iron-Sampling and Preparation of Samples for the Determination of Chemical Composition (IS0 14284:1996)
JB/T 4730.3 Non-destructive Testing of Pressure Equipment Part Three: Ultrasonic Testing
3 Terms and Definitions
This standard applies the following terms and definitions.
3.1
Hollow forging
It refers to axisymmetrical hollow forging, whose axial length L is greater than its outer diameter D, as shown in Fig. 1a). t shall be the nominal thickness.
3.2
Ring forging
It refers to axisymmetrical hollow forging, whose axial length L is less than or equal to its outer diameter D, as shown in Fig. 1b). The smaller one of L and t shall be the nominal thickness.
3.3
Disk forging
It refers to axisymmetrical solid forging, whose axial length l is less than or equal to its outer diameter D, as shown in Fig. 1c). L shall be the nominal thickness. 3.4
Bowl forging
It refers to axisymmetrical forging with concave section, whose length H is less than or equal to its outer diameter D, as shown in Fig. 1d). The greater one between t1 and t2 shall be the nominal thickness.
3.5
Neck flange forging
It refers to axisymmetrical neck flange with two axial outside diameters, as shown in Fig. 1e). The greater one of t1 and t2 shall be the nominal thickness.
3.6
Bar forging
It refers to solid forging with circle section, whose axial length L is greater than its outer diameter D, as shown in fig. 1f). D shall be the nominal thickness.
Forging with rectangular section, whose length L is greater than its side lengths a, b, as shown in Fig. 1g). The smaller one of a and b shall be the nominal thickness.
4 Ordering Information
4.1 The Buyer shall indicate the standard number, steel grade, forging class, supply status and quantity, etc. in the order contract.
4.2 The Buyer shall provide order drawing.
4.3 When the additional requirements in Appendix A (Normative) of this standard and other requirements, which exceed or are higher than this standard are used, they shall be indicated in the order contract by the Buyer.
5 Technical Requirements
5.1 Smelting process
Steel for forging shall be the killed steel smelted by electric furnace, oxygen converter. Smelting methods, such as electroslag remelting, external furnace refining may be used through mutual consultation.
5.2 Chemical composition
5.2.1 The chemical composition (heat analysis) of steel for forging shall comply with the stipulations in Table 1.
5.2.2 It is noted in the contract that P and s contents of 20, 35 and 16Mn steels may be p≤0.025% and S≤0.015% As required by the Buyer.
5.2.3 The Buyer may carry out product analysis, the permissible deviation between the analysis results and the specified values in Table 1 shall comply with the stipulations in Table 2 of GB/T 222. The permissible positive deviation is 0.003% for the steel grade of p≤0.020% in Table 1; the permissible positive deviation is 0.002% for steel type of S≤0.012%.
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Ordering Information
5 Technical Requirements
6 Test Methods
7 Inspection Rules
8 Marking and Quality Certificate
Appendix A (Normative) Additional Requirements
NB/T 47008-2010, NB 47008-2010, NBT 47008-2010, NB/T47008-2010, NB/T 47008, NB/T47008, NB47008-2010, NB 47008, NB47008, NBT47008-2010, NBT 47008, NBT47008
Introduction of NB/T 47008-2010
There have been some significant changes in this standard over JB 4726-2000:
——Design pressure in application scope has been improved to less than 100MPa from not larger than 35MPa;
——Add five steel grades, namely 20MnNiMo, 15NiCuMoNb, 12Cr2Mo1V, 12Cr3MolV and 10Cr9Mo1VNb;
——Degrade phosphorus and sulfur contents of a majority of steel grades;
——Add tensile property index of nominal thickness less than or equal to 100mm for 20Mn and 16Mn steel grades of forgings;
——Improve strength index of 15CrMo and 12CrIMoV steel forgings;
——Improve impact power index of all the steel forgings;
——Describe clearly that the Grade I forgings are only applicable to 20, 35 and 16Mn steel grades of nominal thickness less than or equal to 100mm.
The Appendix A in this standard is normative.
This standard is proposed by and under the jurisdiction of the National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262).
Drafting organizations of this standard: Hefei General Machinery Research Institute, China National General Machinery Engineering Corporation, China Special Equipment Inspection and Research Institute, China First Heavy Industries, Anhui Bureau of Quality and Technical Supervision, Shanghai Power Equipment Research Institute, Wuxi flange forging Co,. Ltd and Jiangyin Fangyuan Ringlike Forging& Flange Co., Ltd
Drafting staffs of this standard: Zhang Xiaohu, Qin Xiaozhong, Zhang Yong, Yang Guoyi, Zhang Wenhui, Zhang Rui, Teng Mingde, Ye Jianping, Chen Zhiwei and Zhao Yuanzhong.
National Technical Committee on Boilers and Pressure Vessels of Standardization Administration of China (SAC/TC 262) is in the charge of the explanation of this standard.
This part replaces the following editions in turn:
——JB 4726-1994;
——JB 4726-2000.
PROFESSIONAL STANDARD
OF THE PEOPLE'S REPUBLIC OF CHINA
中华人民共和国行业标准
NB/T 47008-2010 (JB/T 4726)
Carbon and Alloy Steel Forgings for Pressure Equipments
承压设备用碳素钢和合金钢锻件
1 Scope
This standard specifies the technical requirements, test methods and inspection rules, etc. for carbon steel and alloy steel forgings for pressure equipments.
This standard is applicable to carbon steel and alloy steel forgings for pressure equipments with a design temperature not less than -20℃ and design pressure below 100Mpa.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, only the dated versions apply to this standard. For undated references, the latest edition of the normative document (include all the amendments) is applicable to this standard.
GB/T 222-2006 Permissible Tolerances for Chemical Composition of Steel Products
GR/T 223 Methods for Chemical Analysis of Iron, Steel and Alloy
GB/T 228 Metallic Materials-Tensile Testing at Ambient Temperature (ISO 6892:1998 (E))
GBIT/229-2007Metallic materials-Charpy pendulum impact test method (ISO 148-1:2006)
GB/T 23 1.1 Metallic Materials-Vickers Hardness Test-Part 1: Test Method (1S0 6506-1:2005)
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-Alloy Steel (Routine Method)
GB/T 4338 Metallic Materials-Tensile Testing at Elevated Temperature (ISO 783:1999)
GB/f 6394 Metal-methods for Estimating the Average Grain Size (ASTM E112:1996)
GB/T 10561 Steel-Determination of Content of Nonmetallic Inclusions-Micrographic Method Using Standards Diagrams (1S0 4967: 1998)
GB/T 20066 Steel and Iron-Sampling and Preparation of Samples for the Determination of Chemical Composition (IS0 14284:1996)
JB/T 4730.3 Non-destructive Testing of Pressure Equipment Part Three: Ultrasonic Testing
3 Terms and Definitions
This standard applies the following terms and definitions.
3.1
Hollow forging
It refers to axisymmetrical hollow forging, whose axial length L is greater than its outer diameter D, as shown in Fig. 1a). t shall be the nominal thickness.
3.2
Ring forging
It refers to axisymmetrical hollow forging, whose axial length L is less than or equal to its outer diameter D, as shown in Fig. 1b). The smaller one of L and t shall be the nominal thickness.
3.3
Disk forging
It refers to axisymmetrical solid forging, whose axial length l is less than or equal to its outer diameter D, as shown in Fig. 1c). L shall be the nominal thickness. 3.4
Bowl forging
It refers to axisymmetrical forging with concave section, whose length H is less than or equal to its outer diameter D, as shown in Fig. 1d). The greater one between t1 and t2 shall be the nominal thickness.
3.5
Neck flange forging
It refers to axisymmetrical neck flange with two axial outside diameters, as shown in Fig. 1e). The greater one of t1 and t2 shall be the nominal thickness.
3.6
Bar forging
It refers to solid forging with circle section, whose axial length L is greater than its outer diameter D, as shown in fig. 1f). D shall be the nominal thickness.
Forging with rectangular section, whose length L is greater than its side lengths a, b, as shown in Fig. 1g). The smaller one of a and b shall be the nominal thickness.
4 Ordering Information
4.1 The Buyer shall indicate the standard number, steel grade, forging class, supply status and quantity, etc. in the order contract.
4.2 The Buyer shall provide order drawing.
4.3 When the additional requirements in Appendix A (Normative) of this standard and other requirements, which exceed or are higher than this standard are used, they shall be indicated in the order contract by the Buyer.
5 Technical Requirements
5.1 Smelting process
Steel for forging shall be the killed steel smelted by electric furnace, oxygen converter. Smelting methods, such as electroslag remelting, external furnace refining may be used through mutual consultation.
5.2 Chemical composition
5.2.1 The chemical composition (heat analysis) of steel for forging shall comply with the stipulations in Table 1.
5.2.2 It is noted in the contract that P and s contents of 20, 35 and 16Mn steels may be p≤0.025% and S≤0.015% As required by the Buyer.
5.2.3 The Buyer may carry out product analysis, the permissible deviation between the analysis results and the specified values in Table 1 shall comply with the stipulations in Table 2 of GB/T 222. The permissible positive deviation is 0.003% for the steel grade of p≤0.020% in Table 1; the permissible positive deviation is 0.002% for steel type of S≤0.012%.
Contents of NB/T 47008-2010
Foreword I
1 Scope
2 Normative References
3 Terms and Definitions
4 Ordering Information
5 Technical Requirements
6 Test Methods
7 Inspection Rules
8 Marking and Quality Certificate
Appendix A (Normative) Additional Requirements
