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Standard ID | GB/T 20801.2-2020 (GB/T20801.2-2020) | Description (Translated English) | Pressure piping code -- Industrial piping -- Part 2: Materials | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | J74 | Classification of International Standard | 23.040 | Word Count Estimation | 90,973 | Date of Issue | 2020-11-19 | Date of Implementation | 2021-06-01 | Older Standard (superseded by this standard) | GB/T 20801.2-2006 | Drafting Organization | National Chemical Equipment Design Technology Center Station | Administrative Organization | Pressure Piping Branch of National Boiler and Pressure Vessel Standardization Technical Committee | Regulation (derived from) | National Standard Announcement No. 26 of 2020 | Proposing organization | National Standardization Technical Committee for Boiler and Pressure Vessel (SAC/TC 262) | Issuing agency(ies) | State Administration for Market Regulation, National Standardization Administration | Standard ID | GB/T 20801.2-2006 (GB/T20801.2-2006) | Description (Translated English) | Pressure piping code. Industrial piping. Part 2: Materials [Quasi-Official / Academic version - scanned PDF, translated by Standard Committee / Research Institute in China] | Sector / Industry | National Standard (Recommended) | Classification of Chinese Standard | J74 | Classification of International Standard | 23.040 | Word Count Estimation | 69,643 | Date of Issue | 2006-12-30 | Date of Implementation | 2007-06-01 | Quoted Standard | GB 150; GB/T 229-1994; GB/T 700-2006; GB 713-1997; GB/T 1220-1992; GB/T 1348-1988; GB/T 2054-2005; GB/T 2882-2005; GB/T 3077-1999; GB 3087-1999; GB/T 3091-2001; GB/T 3098.1-2000; GB/T 3098.6-2000; GB 3531-1996; GB/T 3621-1994; GB/T 3624 - 1995; GB/T 3880.2-2006; GB/T 4237-1992; GB/T 4437.1-2000; GB 5310-1995; GB 6479-2000; GB/T 6614-1994; GB 6654-1990; GB/T 6893 - 2000; GB/T 8163-1999; GB/T 9439-1988; GB/T 9440-1988; GB/T 9711.1-1997; GB 9948-2006; GB/T 12229-2005; GB/T 12230-2005; GB/T 12459-2005; GB/T 12771-2000; GB/T 12778-1991; GB/T 13401-2005; GB/T 14976-2002; GB/T 16253-1996; GB/T 16598-1996; GB/T 18984-2003; GB/T 20801.1-2006; GB/T 20801.3-2006; HG/T 3651-1999; HG/T 20537.3-1992; HG/T 20537.4-1992; JB 4726-2000; JB 4727-2000; JB 4738-2000; JB 4741-2000, | Drafting Organization | National Chemical Equipment Design Technology Center | Administrative Organization | National Standardization Technical Committee Boiler and Pressure Vessel | Regulation (derived from) | China National Standard Approval Announcement 2006 No.13 (Total No.100) | Proposing organization | National Standard Committee on Boiler and Pressure Vessel Pressure Pipeline Subcommittee (SAC/TC 262/SC 3) | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of PRC, China National Standardization Administration Committee | Summary | This standard specifies the basic requirements for pressure pipeline construction materials. These basic requirements include material selection, use restrictions, prescribed inspection requirements and marking area. |
GB/T 20801.2-2020
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 23.040
J 74
Replacing GB/T 20801.2-2006
Pressure piping code - Industrial piping - Part 2:
Materials
ISSUED ON: NOVEMBER 19, 2020
IMPLEMENTED ON: JUNE 01, 2021
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 9
4 General rules ... 11
5 Basic principles of material selection ... 13
6 Restrictions on the use of materials ... 13
7 Restrictions on the use of materials under high temperature conditions ... 21
8 Restrictions on the use of materials under low temperature conditions ... 24
9 Material marking and quality certification ... 34
Appendix A (Normative) Material designation and allowable stress ... 36
Appendix B (Informative) Physical properties of materials ... 72
Appendix C (Informative) Risk-based material design and selection ... 78
Appendix D (Informative) Comparison of material standards and designations
between China and foreign countries ... 113
References ... 124
Pressure piping code - Industrial piping - Part 2:
Materials
1 Scope
This Part of GB/T 20801 specifies the basic requirements for materials for
pressure piping components, including the selection of materials, restrictions
on use based on material properties, marking and quality certification.
This Part applies to the selection and use of materials, for pressure piping
components, which are defined in the scope of GB/T 20801.1.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) is applicable to this standard.
GB/T 229 Metallic materials - Charpy pendulum impact test method
GB/T 1220 Stainless steel bars
GB/T 1348 Spheroidal graphite iron castings
GB/T 2882 Nickel and nickel alloys tube
GB/T 3077 Alloy structure steels
GB/T 3087 Seamless steel tubes for low and medium pressure boiler
GB/T 3091 Welded steel pipes for low pressure liquid delivery
GB/T 3098.1 Mechanical properties of fasteners - Bolts, screws and studs
GB/T 3098.6 Mechanical properties of fasteners - Stainless steel bolts,
screws and studs
GB/T 3624 Titanium and titanium alloy seamless tubes
GB/T 4334 Corrosion of metals and alloys - Test methods for intergranular
corrosion of stainless steels
The owner or designer shall select appropriate materials for piping components,
according to the specific use conditions (including manufacturing, fabrication
and installation, media, operating conditions, working environment, testing, etc.)
AND the material use requirements and restrictions specified in this Part,
considering the risk of material damage. This Part does not include material
requirements for welding, non-metal, etc.
4.2 Material and technical requirements
4.2.1 Table A.1 and Table A.2 of Appendix A specify the designations, allowable
stress and application range of the piping component materials. The materials,
which are used for the piping components, shall comply with the requirements
of the material standards, as listed in Table A.1 and Table A.2.
See Appendix B for the physical performance parameters of the material. Refer
to Appendix C, for the selection of commonly used pipeline materials, damage
risks, corresponding material design requirements, engineering measures.
4.2.2 In addition to the materials listed in Table A.1 and Table A.2, the following
materials can be used for piping components; however, they shall meet the
requirements and use restrictions for corresponding materials in this Part:
a) Other designations of materials, which are listed in the applicable material
standards for industrial piping, as listed in Table A.1 and Table A.2;
b) The material meets the published material standards, including chemical
composition, physical properties, mechanical properties, manufacturing
methods and processes, heat treatment and quality control, etc. It is not
lower than the requirements of the corresponding material standards,
which are listed in Table A.1 and Table A.2;
c) Standard applicable materials for piping components, which are listed in
Table 13 of GB/T 20801.3-2020;
d) The foreign standard materials, which are listed in Appendix D,
corresponding to the materials listed in Table A.1 and Table A.2.
4.2.3 Materials with unknown designations shall not be used for piping
components.
4.2.4 The recovered materials shall not be used in piping components.
4.2.5 The selection of other materials shall be subject to technical appraisal and
review & approval, by institutions with corresponding qualifications.
5 Basic principles of material selection
5.1 The materials, which are used for pressure components (except bolts), shall
have sufficient strength, plasticity, toughness. They shall have sufficient
resistance to brittle fracture, at the lowest use temperature. When brittle
materials, which have an elongation rate of less than 14%, are used, it shall
take necessary safety protection measures.
5.2 The selected materials shall have sufficient stability, including chemical
properties, physical properties, corrosion and wear resistance, fatigue
resistance, organizational stability.
5.3 When selecting materials, it shall consider the applicability of the materials
under possible open flames, fires and extinguishing conditions, as well as
changes in material properties and secondary hazards, which are brought
about by this.
5.4 The selected materials shall be suitable for the corresponding
manufacturing, production, installation, including welding, cold and hot
processing, heat treatment requirements.
5.5 When several different materials are used in combination, it shall consider
the possible adverse effects.
5.6 Materials shall be available and economical.
6 Restrictions on the use of materials
6.1 Nodular cast iron, gray cast iron, malleable cast iron
6.1.1 Nodular cast iron
6.1.1.1 When nodular cast iron is used for piping components, its elongation
shall not be less than 15%; the use temperature shall not be higher than 350 °C,
but it shall be higher than -20 °C. The use restrictions of nodular cast iron piping
components, which are listed in Table 13 of GB/T 20801.3-2020, shall comply
with the corresponding requirements of GB/T 13295.
6.1.1.2 Except for GC3 grade pipes, nodular cast iron shall meet the impact
performance requirements of GB/T 1348; the pressure rating shall not exceed
5.0 MPa.
6.1.1.3 Nodular cast iron shall not be used in severe cyclic conditions.
6.1.1.4 In addition to meeting the requirements of 6.1.1.1, 6.1.1.2, 6.1.1.3, the
applicable pressure-temperature ratings of nodular cast iron pipes, fittings,
accessories, pipe flanges, valves shall also comply with the requirements of the
corresponding standards, in Table 13 of GB/T 20801.3-2020.
6.1.1.5 Welding is not allowed, during manufacturing, production, installation.
6.1.2 Gray cast iron and malleable cast iron
6.1.2.1 When the gray cast iron and malleable cast iron, which are listed in
Table A.1, are used for piping components, they shall meet the following
requirements:
a) The use temperature of gray cast iron piping components shall not be
lower than -10 °C and not higher than 230 °C; the pressure rating shall
not be higher than 2.0 MPa;
b) The use temperature of malleable cast iron piping components shall not
be lower than -20 °C and not higher than 300 °C; the pressure rating shall
not be higher than 2.0 MPa;
c) Gray cast iron and malleable cast iron piping components shall not be
used for GC1 grade pipes or severe cyclic conditions;
d) When gray cast iron and malleable cast iron piping components are used
for GC2 grade pipelines, their use temperature shall not be higher than
150 °C; the maximum allowable working pressure shall not be greater than
1.0 MPa;
e) Safety protection measures shall be taken, to prevent overheating, rapid
cold and rapid heat, vibration, mis-operation;
f) No welding is allowed, during manufacturing, production, installation.
6.1.2.2 In addition to meeting the requirements of 6.1.2.1, the applicable
pressure-temperature ratings of gray cast iron and malleable cast iron pipes,
fittings, pipe flanges, valves shall also meet the requirements of the
corresponding standards, in Table 13 of GB/T 20801.3-2020.
6.2 Carbon structural steel
The restrictions on the use of carbon structural steel shall meet the following
requirements:
a) It shall not be used for GC1 grade piping components;
b) When using grade A killed steels, such as Q215A and Q235A, the design
pressure shall not be greater than 1.6 MPa; the design temperature shall
not be higher than 350 °C and not lower than the temperature as shown
6.6.1 Low-carbon (carbon content ≤ 0.08%) non-stabilized stainless steel (such
as 06Cr19Ni10, 06Cr17Ni12Mo2), in a non-solid solution state (including hot
working or welding after solid melting), should not be used in an environment,
where intergranular corrosion may occur. Please refer to Appendix C, for
material requirements.
6.6.2 Ultra-low carbon stainless steel has a tendency of intergranular corrosion,
when used for a long time above 425 °C. For material requirements, see
Appendix C.
6.6.3 For low-carbon/ultra-low-carbon austenitic stainless steels and other dual-
designation steels, its mechanical properties at room temperature shall meet
the higher value of the mechanical properties of the two designations; the
chemical composition shall meet the requirements of ultra-low-carbon grade. If
the use temperature is not higher than 538 °C, the allowable stress is selected
according to the low-carbon grade; if the use temperature is higher than 538 °C,
the allowable stress is selected according to the ultra-low carbon grade.
6.6.4 According to the requirements of the design documents, austenitic
stainless steel can be subjected to intergranular corrosion test, according to
GB/T 4334, OR stress corrosion test or pitting corrosion test, according to
relevant standards. The test method, specimen state, sampling ratio,
qualification index shall be defined in the design document.
6.7 Plate-welded pipe
6.7.1 Plate-welded pipes shall be formed by longitudinal coils of steel plates,
which have one or two longitudinal straight welds. Limited by the width of the
steel plate, plate-welded pipes of larger diameter can be formed by lateral
rolling the steel plates. Except for GB/T 3091 and SY/T 5037, the negative
deviation of the thickness of the plate-welded pipe shall not be greater than 0.3
mm; the size deviation of the plate-welded pipe shall be in accordance with the
relevant standards, such as GB/T 9711.
6.7.2 Steel pipes shall be manufactured by electrofusion welding process.
Except for GB/T 3091 and SY/T 5037, plate-welded pipes shall be of full
penetration structure. Carbon steel, pipeline steel, low-temperature carbon
steel, nickel steel, alloy steel shall be double-sided submerged arc welding or
gas shielded welding; stainless steel shall be double-sided gas shielded
welding, which is added with wire or not.
6.7.3 The chemical composition of the weld shall be close to or equivalent to
that of the base metal; its performance shall not be lower than that of the base
metal. The PSL2 plate-welded pipe in GB/T 9711 shall be subjected to an
impact test, which is not higher than the minimum design temperature AND not
lower than -30 °C. For steel pipes requiring impact tests, it shall include the
base metal, welds, heat-affected zone.
6.7.4 Except for the PSL2 plate-welded pipes in GB/T 9711, low-temperature
carbon steel plate-welded pipes, which require an impact test lower than or
equal to 0 °C, shall be normalized steel plates. Carbon steel and low-
temperature carbon steel plate-welded pipes, which have a thickness greater
than or equal to 20 mm, shall be subjected to post-weld stress relief heat
treatment. All chromium-molybdenum alloy steel plate-welded pipes shall be
subjected to post-weld stress relief heat treatment. Unless otherwise specified
by the owner or design, austenitic stainless steel and Duplex stainless steel
plate-welded pipes shall be solution-treated after welding.
6.7.5 Except for GC3 grade pipelines and the plate-welded pipes of GB/T 3091,
SY/T 5037, local or 100% radiographic or ultrasonic testing shall be carried out,
on the welds of plate-welded pipes; it shall comply with the corresponding
requirements in 6.3.2 of GB/T 20801.5-2020.
6.7.6 Welded pipes, which are used under severe cyclic conditions, shall adopt
a welding process with filler metal, AND be subject to local or 100%
radiographic or ultrasonic testing; it shall comply with the corresponding
requirements in 6.3.2 of GB/T 20801.5-2020.
6.8 Aluminum and aluminum alloy
6.8.1 The mechanical properties of aluminum and aluminum alloys are related
to thickness and delivery status. The properties and allowable stresses, which
are listed in Table A.1, are only applicable to the specified range of the
corresponding standards.
6.8.2 If the material standard does not specify the tensile and yield strength,
this Part requires supplementation in the purchase contract.
6.8.3 The welding structure of the material, in the work-hardened state, shall
adopt the allowable stress of the corresponding designation in the annealing
state; the welding structure of the material, in the precipitation hardened state,
shall adopt the allowable stress of the corresponding designation in the welding
state.
6.8.4 The performance and allowable stress of aluminum and aluminum alloy
pipe fittings are related to the blank, process and heat treatment state; it can
refer to the performance and allowable stress of seamless pipes, welded pipes,
plates, rods, forgings of the same designation. The performance and allowable
stress, which are listed in Table A.1, are typical examples.
6.9 Nickel and nickel alloys
6.9.1 The mechanical properties of nickel and nickel alloys are related to the
processing and heat treatment conditions. The properties and allowable
stresses, which are listed in Table A.1, are only applicable to the specified range
of the corresponding standards.
6.9.2 The performance and allowable stress of nickel and nickel alloy pipe
fittings are related to the blank, process, heat treatment state. It may refer to
the performance and allowable stress of seamless pipes, welded pipes, plates,
rods, forgings of the same designations. The performance and allowable stress,
which are listed in Table A.1, are typical examples.
6.9.3 The tensile strength of joints, which are welded by ENiCrMo-3 or
ERNiCrMo-3 of 625 nickel-based alloy, shall not be less than 758 MPa.
6.9.4 Thermal history of 625 nickel-based alloy, at 538 °C ~ 760 °C, may cause
the reduction of room temperature toughness and stress relaxation cracks, in
the welding area, see Appendix C.
6.10 Pipe support material
6.10.1 The standards, materials, allowable stresses, which are listed in Table
A.1 and Table A.2, also apply to pipe supports.
6.10.2 The other requirements of the pipe support material shall be in
accordance with the provisions of Chapter 8 of GB/T 20801.3-2020.
6.11 Low melting point metals
6.11.1 Low melting point metals, such as lead and zinc, as well as their alloys,
shall not be used in pipelines for conveying combustible media.
6.11.2 Low melting point metals, such as lead and zinc, shall be prevented from
liquid-metal corroding the austenitic stainless steel and nickel-based alloys,
during heat treatment, welding or high-temperature use. Refer to Appendix C.
7 Restrictions on the use of materials under high
temperature conditions
7.1 Upper limit of material's use temperature
7.1.1 Table A.1 and Table A.2 specify the upper limit of the material's use
temperature, under normal circumstances.
7.1.2 When determining the upper limit of the use temperature of the material,
it shall consider the influence of the medium and the environment.
7.2 Principles for the selection of high-temperature materials
7.2.1 General requirements
7.2.1.1 For materials, which are used for a long time under high temperature
conditions, it shall consider the influence of organization or performance
changes, on the reliability of the material.
7.2.1.2 For materials, which are used for a long time under high temperature
conditions, it shall consider the excessive deformation, excessive displacement,
deterioration of material structure and performance, stress relaxation of bolts,
due to creep. See Table 5 of the GB/T 20801.3-2020, for the creep threshold
temperature of typical metal materials. Other metal materials can be found in
Appendix C.
7.2.1.3 For materials, which are used under high temperature conditions, it shall
consider the material damage, which is caused by high temperature and
chemical corrosion.
7.2.1.4 For materials strengthened by heat treatment, if they are used at
temperatures close to or higher than the tempering temperature for a long
period of time, it shall consider the reduction in material strength.
7.2.2 The use of carbon steel and chromium-molybdenum alloy steel
under high temperature conditions
7.2.2.1 The high-temperature strength reduction factor W of welded joints,
under high-temperature creep conditions, is in accordance with the provisions
of 4.2.7 in GB/T 20801.3-2020.
7.2.2.2 Refer to Appendix C, for the high-temperature graphitization tendency
of carbon steel, carbon-manganese steel, low-temperature nickel steel, as well
as the softening (pearlite spheroidization) tendency of chromium-molybdenum
alloy steel.
7.2.2.3 Refer to Appendix C for the temper brittleness sensitivity of chromium-
molybdenum alloy steel.
7.2.3 The use of stainless steel under high temperature conditions
7.2.3.1 Under the high-temperature creep conditions (see 3.2 of GB/T 20801.3-
2020), the high-temperature strength reduction factor W of stainless steel
welded joints shall be in accordance with the provisions of 4.2.7 in GB/T
20801.3-2020.
7.2.3.2 Refer to Appendix C, for the brittleness sensitivity of ferritic stainless
steel, martensitic stainless steel, duplex stainless steel, at 475 °C.
7.2.3.3 Refer to Appendix C, for the σ-phase embrittlement sensitivity of
of carbon steel, low temperature steel, chromium-molybdenum alloy steel,
ferritic stainless steel, duplex stainless steel, shall meet the requirements of
Table 6 and Table A.1.
8.1.3.2 The welding procedure qualification of materials shall meet the
requirements of Table 8, Table 11, Table 12.
8.1.3.3 When carbon steel (including carbon-manganese steel) meets low-
temperature low-stress or low-temperature stress-reducing conditions, the
minimum use temperature for exemption from impact test may be lower than
that specified in 8.1.3.1, AND it shall meet the following requirements:
a) For the carbon steel (including carbon-manganese steel), that meets the
low-temperature stress-reducing conditions, the reduction of the minimum
use temperature, at which the material can be exempted from the impact
test, is 11 °C; meanwhile the minimum use temperature shall not be lower
than -30 °C, BUT shall meet the following requirements:
1) The pipeline shall undergo a hydraulic test, which is not less than 1.5
times the design pressure;
2) Except for the nominal wall thickness less than or equal to 13 mm, the
piping system shall be protected against external loads (such as
maintenance load, impact load, thermal shock load, etc.);
3) Low-temperature stress-reducing conditions are applicable to GC2
grade pipelines, as well as the GC3 grade pipelines in areas, where the
ambient temperature is not higher than -20 °C but not lower than -30 °C;
meanwhile, the applicable carbon steel materials do not contain carbon
structural steel and bolt materials; the existence of ferrite and austenite
dissimilar metal welded joints is not allowed in the piping system.
Note: The lowest ambient temperature is the lowest value of the monthly average
lowest temperature over the years.
b) For GC2 grade pipeline, which conforms to low-temperature low-stress
conditions, the minimum use temperature shall not be lower than -104 °C;
the applicable carbon steel materials do not contain carbon structural steel
and bolt materials; the existence of ferrite and austenite dissimilar metal
welded joints is not allowed in the piping system.
with thread diameter less than or equal to M52, which has the minimum
tensile strength of the material as specified in the standard, of less than
655 MPa, the impact test shall meet the requirements of Table 11;
b) For the notch of the bolt material with a thread diameter larger than M52
and the impact specimen of austenitic stainless steel, the lateral
expansion shall meet the requirements of Table 12.
9 Material marking and quality certification
9.1 Material marking
9.1.1 The marking of materials shall comply with the requirements of the
corresponding standards and contracts.
9.1.2 The content of the marking shall include at least the manufacturer's mark
and the name of the material (code). The marking of the following piping
components shall also include the furnace batch number or code of the material:
a) Piping components for GC1 grade pipelines;
b) The piping components subjected to the impact test according to the
requirements of this Part;
c) Chromium-molybdenum alloy steel (except bolt materials) piping
components;
d) Austenitic stainless steel (H-type) piping components used under high
temperature conditions;
e) Nickel and nickel alloy, titanium and titanium alloy piping components.
9.1.3 Materials shall be marked piece by piece. The markings shall be clear and
firm. Materials, which have a nominal diameter less than or equal to DN40, can
be marked with labels or other alternative methods.
9.2 Quality certification
The quality certification of the material shall meet the following requirements:
a) The materials shall have corresponding quality certification documents;
b) The quality certification documents shall include the standards and the
inspection and test results, which are specified in the contract; they shall
be traceable;
c) Quality certification documents (certificates), that do not include inspection
......
ICS 23.040
J74
National Standard of the People's Republic of China
Pressure Piping Code-Industrial Piping
Part 2. Materials
ISSUED ON. DECEMBER 30, 2006
IMPLEMENTED ON. JUNE 1, 2007
Issued by General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China
Standardization Administration of the People's Republic of China
Contents
Scope . 1
2 Normative References . 1
3 Terminologies and Definition .. 3
4 General Rules .. 4
4.1 Selection of Materials .. 4
4.2 Material Brand and Allowable Stress .. 4
5 Basic Rules for Material Selection . 4
6 Limits of Material Application . 5
6.1 Ductile Iron, Grey Cast Iron and Malleable Cast Iron .. 5
6.2 Structural Steels . 6
6.3 Pipes and Fittings .. 6
6.4 Carbon Steel and Cr-Mo Alloy Steel... 6
6.5 Austenitic Stainless Steel... 7
6.6 Aluminum and Aluminum Alloy . 7
6. 7 Low-Melting Metal... 7
7 Materials Application Limits at High Temperature .. 8
7.1 Upper Temperature Limit to Material Application .. 8
7 .2 Principles for Selection of High Temperature Materials .. 8
8 Limitation to Material Used at Low Temperature . 9
8.1 Lowest Application Temperature and Impact Test Exemption .. 9
8.2 Impact Test .. 13
9 Material Identification and Quality Certificate . 16
9 .1 Material Identification .. 16
9.2 Quality Certificate . 16
Appendix A (Normative Appendix) Material Brand and Allowable Stress .. 18
Appendix B (Informative Appendix) Physical Properties of Materials . 55
Pressure Piping Code-Industrial Pipelines
Part 2. Materials
1 Scope
This part specifies basic requirements for pressure pipeline construction materials, which
include rules for material selection, application limits, inspection requirements and identification.
2 Normative References
Clauses contained in the following documents are referred by this part of GB/T 20801
and become clauses of this part. Any reference document with date indicated and their
subsequent modification sheets (excluding error corrections) or revised editions do not apply
to this part, however, all parties who enter into an agreement based on this part are
encouraged to probe into possibility of use of the latest editions of such documents. For any
reference document without date indicated, their latest editions are applicable to this part.
GB 150 Steel Pressure Vessels
GB/T 229-1994 Method for Metal Charpy Notch Impact Test (eqv ISO 148.1983)
GB/T 700-2006 Structural Carbon Steel
GB 713-1997 Boiler-Used Steel Plates (neq ISO 5832-4.1996)
GB/T 1220-1992 Stainless Steel Bars
GB/T 1348-1988 Ductile Iron Castings
GB/T 2054-2005 Nickel and Nickel Alloy Plates
GB/T 2882-2005 Nickel and Nickel Alloy Pipes
GB/T 3077-1999 Structural Alloy Steel
GB/T 3087-1999 Seamless Steel Pipes for Low and Middle Pressures (neq ISO
9329-1. 1989)
GB/T 3091-2001 Welded Steel Pipes for Low Pressure Fluid Transmission (neq ISO
559-1. 1991)
GB/T 3098.1-2000 Mechanical Properties of Fasteners. Bolts, Screws and Studs (idt
ISO 898-1. 1999)
GB/T 3098.6-2000 Mechanical Properties of Fasteners. Stainless Steel Bolts, Screws
and Studs (idt ISO 3506-1.1997)
GB353 l-1996 Low Alloy Steel Plates for Low-Temperature Pressure Vessels
GB/T 3621 -1994 Titanium and Titanium Alloy Plates
GB/T 3624-1995 Titanium and Titanium Alloy Pipes
GB/T 3880.2-2006 Aluminum and Aluminum Alloy Plates for General Industries.
Part 2. Mechanical Properties
GB/T 4237-1992 Hot Rolled Stainless Steel Plates
GB/T 4437.1-2000 Hot Extruded Aluminum and Aluminum Alloy Pipes. Part 1.
Seamless Round Pipes
GB 5310-1995 Seamless Steel Pipes for High-Pressure Boilers
GB 64 79-2000 Seamless Steel Pipes for High-Pressure Chemical Fertilizer Equipment
GB/T 6614-1994 Titanium and Titanium Alloy Castings
GB 6654-1996 Steel Plates for Pressure Vessels
GB/T 6893-2000 Drawn (Rolled) Seamless Aluminum and Aluminum Alloy Pipes
(neq ISO 559.1991)
GB/T 8163-1999 Seamless Steel Pipe for Fluid Transmission (neq ISO 559.1991)
GB/T 9439-1998 Gray Iron Castings
GB/T 9440-1988 Malleable iron castings (neq ISO 5922.1981)
GB/T 9711.1-1997 Technical Specification for Delivery of Steel Pipes for Transmission
oflndustrial Petroleum and Natural Gas. Part 1. Grade A Steel Pipe (eqv ISO 3183-1.1996)
GB 9948-2006 Seamless Steel Pipes for Petroleum Cracking
GB/T 12229-2005 General-Purpose Valves. Technical Specification for Carbon Steel
Castings
GB/T 12230-2005 General-Purpose Valves. Technical Specification for Stainless Steel
Castings
GB/T 12459-2005 Butt-Welded Seamless Steel Pipe Fittings
GB/T 12771-2000 Welded Stainless Steel Pipes for Fluid Transmission
GB/T 12778-1991 Method for Metal Charpy Impact Notch Determination
GB/T 13401-2005 Steel Plate Butt-Welded Pipe Fittings
GB/T 14976-2002 Seamless Stainless Steel Pipes for Fluid Transmission
GB/T 16253-1996 Pressure-Resistant Steel Castings (eqv ISO 4991.1994)
GB/T 16598-1996 Titanium and Titanium Alloy Cakes and Rings
GB/T 18984-2003 Seamless Steel Pipes for Low-Temperature Pipelines
GB/T 20801.1-2006 Pressure Piping Code-Industrial Pipelines. Part 1. General
GB/T 20801. 3 -2006 Pressure Piping Code-Industrial Pipelines. Part 3. Design and
transmit flammable substances.
7 Materials Application Limits at High Temperature
7.1 Upper Temperature Limit to Material Application
a) Upper temperature limits to material application under general conditions are
specified in Table A.1 and Table A.2 of Appendix A;
b) Upper temperature limits to material application shall be determined considering
corrosive media impact.
7.2 Principles for Selection of High Temperature Materials
7.2.1 General Requirements
a) For materials for long-term use at high temperature, effect on material application
reliability due to structure or property changes shall be taken into consideration.
b) For materials for long-term use at temperature higher than creep temperature, excess
deformation, excess displacement, material structure and performance degradation
and bolt stress relaxation due to creepage shall be taken into consideration;
c) For materials used at high temperature, material failure due to chemical corrosion
shall be taken into consideration.
d) For materials reinforced through hear treatment, if used at temperature close to or
higher than drawing temperature for long-term use, material strength factor shall be
taken into consideration.
7.2.2 Application of Carbon Steel and Cr-Mo alloy at High Temperature
a) By considering that carbide may possibly be changed into graphite, carbon steel,
manganese carbon steel and low-temperature nickel steel shall not be used for long
time at temperature higher than 425°C, Mo-C steel shall not be used for long time at
temperature higher than 470°C;
b) In view of potential temper brittleness, if Cr-Mo alloy steel is to be used at 444 °C
,.,550 °C for long time, proper measures shall be taken based on application
experience and Specific working conditions.
7.2.3 Usage of Stainless Steel at High Temperature
a) In view of material brittleness, ferritic stainless steel and martensite stainless steel
shall not be used at temperature higher than 3 7 0 °C;
b) Because of potential cr-phase brittleness caused when Cr-Ni austenitic stainless steel
is used at 540 °C ,.,900 °C for long time, ferrite content in martensite stainless steel
and excess cold deformation shall be controlled during use;
c) Because of 475°C brittleness and cr-phase brittleness, duplex stainless steel shall not
be used at temperature higher than 3 00 °C ;
d) Because of intercrystalline attack of austenitic stainless steel caused at high
temperature (higher than melting points of low-melting metals) by Al, Sb, Bi, Cd,
8.2.2 Impact Test of Welded Joint
a) Impact test of welded joint shall be performed in welding process assessment;
b) Preparation of Test piece, location and number of samples to be taken for impact
test shall conform to specification provided in Table 7;
c) Weld joint impact test of materials listed in Table 4 shall include weld metal and
heat affected area, but weld joint impact test of austenitic stainless steel includes
weld metal only.
8.2.3 Procedure for Impact Test
a) Procedure for impact test shall be in accordance with specifications stated in GB/T
229-1994 and GB/T 12778-1991;
b) Standard impact specimen shall be a Charpy notch impact specimen of 1 Ommx
10mmx55mm;
c) If standard specimen can not be prepared due to limited cross section dimensions, a
small specimen with thickness 7.5 mm or 5.0 mm or 2.5 mm or small specimen as
wide as possible may be used. Notch width of a small-sized specimen shall
generally be not be 80% less than material thickness;
d) Specimen notch shall be cut along thick direction. Three specimen constitute a
group.
8.2.4 Impact Test Temperature
a) Impact test temperature of standard specimen shall be no higher than the lowest
design temperature;
b) Reduction value of impact test temperature of small-sized specimen shall meet
specifications given in Table 8 and 9;
c) Reduction value of impact test temperature of small-sized specimen is only
applicable to impact work taken as qualification criteria, whereas impact test
temperature with lateral expansion value of impact fracture as qualification criteria
shall meet specification described in Table 11.
8.2.5 Qualification Criteria
a) For carbon steel, alloy steel and low-temperature steel with min. tensile strength less
than 655MPa specified in material standard as well as bolt materials with thread
diameter less than or equal to M52, their impact tests shall meet specifications
stipulated in Table 1 O;
b) Lateral expansion value of impact specimen fracture of bolt materials with thread
diameter more than M52 and austenitic stainless steel shal...
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