NB/T 47008-2010 (NBT47008-2010)

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NB/T 47008-2010	English	115	Add to Cart	0--9 seconds. Auto-delivery	Carbon and alloy steel forgings for pressure equipment	NB/T 47008-2010	Obsolete	NB/T 47008-2010

ICS 77.140.85
J 32 NB
PROFESSIONAL STANDARD OF
THE PEOPLE'S REPUBLIC OF CHINA
NB/T 47008-2010 (JB/T 4726)
Replace JB 4726-2000
Carbon and Alloy Steel Forgings for
Pressure Equipments
Issued on August 27, 2010 Implemented on December 15, 2010
Issued by the National Energy Administration
Contents
Foreword ... II
1 Scope ... 1
2 Normative References ... 1
3 Terms and Definitions ... 2
4 Ordering Information ... 2
5 Technical Requirements ... 3
6 Test Methods ... 9
7 Inspection Rules ... 1 0
8 Marking and Quality Certificate ... 12
Appendix A (Normative) Additional Requirements ... 13
Foreword
There have been some significant changes in this standard over JB 4726-2000.
--Design pressure in application scope has been improved to less than lOOMPa from
not larger than 35MPa;
--Add five steel grades, namely 20MnNiMo, 15NiCuMoNb, 12Cr2MolV,
12Cr3MolV and 10Cr9MolVNb;
--Degrade phosphorus and sulfur contents of a majority of steel grades;
--Add tensile property index of nominal thickness less than or equal to lOOmm for
20Mn and 16Mn steel grades offorgings;
--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 lOOmm.
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
NBff 47008-2010 (JBff 4726)
Carbon and Alloy Steel F orgings for Pressure Equipments
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'C and design pressure below lOOMpa.
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
GRIT 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 (1SO
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 E 112. 1996)
GB/T 10561 Steel-Determination of Content of Nonmetallic Inclusions-Micrographic
Method Using Standards Diagrams (1SO 4967. 1998)
GB/T 20066 Steel and Iron-Sampling and Preparation of Samples for the Determination
of Chemical Composition (ISO 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 defmitions.
3.1
Hollow forging
It refers to axisymmetrical hollow forging, whose axial length Lis greater than its outer
diameter D, as shown in Fig. la). 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. lb). The smaller one ofL and t shall be the nominal
thickness.
3.3
Disk forging
It refers to axisymmetrical solid forging, whose axial length 1 is less than or equal to its
outer diameter D, as shown in Fig. le). L shall be the nominal thickness. 3.4
Bowl forging
It refers to axisymmetrical forging with concave section, whose length His less than or
equal to its outer diameter D, as shown in Fig. ld). 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.
le). The greater one oft1 and t2 shall be the nominal thickness .
3.6
Bar forging
It refers to solid forging with circle section, whose axial length Lis greater than its outer
diameter D, as shown in fig. lf). D shall be the nominal thickness.
Forging with rectangular section, whose length Lis greater than its side lengths a, b, as shown
in Fig. lg). 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.
5.3 Forging
5.3.1 Steel ingot, billet steel, rolled metal used for forging shall be accompanied with the
quality certificate of the smelter.
5.3.2 There must be sufficient truncation margin at the head and end of the steel ingot used
for forging so as to ensure no defects, such as pipe and severe segregation, on the forging.
5.3.3 Forging ratio of main section of the forging shall not be less than 3 (not less than 2 for
electroslag remelting steel) when steel ingot or billet steel is used for forging. And the forging
ratio of main section of the forging shall not be less than 1.6 when rolled metal is used for
forging.
5.3.4 The forging shall be formed through hot working by press, forging hammer or rolling
mills, the metal on the whole section shall be forged thoroughly and close to the shape and
size of the finished parts as far as possible.
5.4 Forging classes
Forgings are divided into four classes of I, II, Ill and IV. The inspection item of each
class shall follow the stipulations in Table 2. Class I forging is only applicable to 20, 35 and
16l\1n steel forgings of nominal thickness less than or equal to lOOmm.
Table 2
Forging class Inspection item Inspection quantity
I Hardness (HB) Inspected piece by piece
II Tension and impact (Rm, ReL, A, KV 2) Forgings smelted in the same heat
number and heat treated in the same
furnace shall compose a batch and one
Tension and impact (Rm, ReL. A, KV 2)
m piece shall be inspected at random for
one batch.
Ultrasonic inspection Inspected piece by piece
IV
Tension and impact (Rm, ReL, A, KV2) Inspected piece by piece
Ultrasonic inspection Inspected piece by piece
5.5 Heat treatment
Forgings shall be delivered at the heat treatment status specified in Table 3. If the
supplier needs changing the heat treatment status, approval shall be obtained from the Buyer.
The codes for heat treatment status are. N- normalizing, Q-quenching, T-tempering.
5.6 Mechanical property
5.6.1 Hardness value of Class I forgings shall be in accordance with those specified in Table
3. The hardness value in the table is the arithmetical mean of the test results of three
determination results and the single mean values shall not exceed lOHBW of the specified
range in the table.
5.6.2 Tension and impact property of Classes II, Ill and IV shall be in accordance with those
specified in Table 3.The impact power in this table is the arithmetic mean of three specimen
testing results; the impact power of one specimen lower than the specified value is acceptable,
however, not lower than 70% of the specified value.
5.6.3 It is noted in the contract that 20, 16l\1n and 20 l\1nMo steel forgings may have -20 'C
impact test instead ofO 'C impact test in Table 3 As required by the Buyer; the index of -20'C
impact power shall be according to those specified in Table 3.
6.1 Chemical analysis
Chemical analysis shall be carried out as per GB/T 223 or GB/T 4336. Arbitration test
shall be carried out as per GB/T 223.
6.2 Hardness test
Hardness test shall be carried out as per GB/T 231.1. Other method may also be used
when necessary.
6.3 Tensile test
Tensile test shall be carried out as per GB/T 228.
6.4 Impact test
Impact test shall be carried out as per GB/T 229.
6.5 Ultrasonic inspection
Ultrasonic inspection shall be carried out as per JB 4730.3.
7 Inspection Rules
7.1 Forgings shall be inspected by the suppl...