GB/T 150.2-2024 Pressure vessels - Part 2: Materials
1 Scope
This document specifies the allowable grades and standards of steel materials for pressure parts of steel pressure vessels, the additional technical requirements of steel materials, the application scope (temperature and pressure) of steel materials, the allowable stress of steel materials, and the basic requirements of welding materials.
This document is applicable to the pressure vessels with design temperature of -269°C ~ 800°C and the design pressure not greater than 35 MPa.
This document is not applicable to the scope of inapplicability specified in GB/T 150.1.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 150.1 Pressure vessels - Part 1: General requirements
GB/T 150.3 Pressure vessels - Part 3: Design
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 699 Quality carbon structure steels
GB/T 700 Carbon structural steels
GB/T 709 Dimension, shape, weight and tolerance for hot-rolled steel strip, plate and sheet
GB/T 713.7 Steel plate, sheet and strip for pressure equipments - Part 7: Stainless steel and heat resisting steel
GB/T 1220 Stainless steel bars
GB/T 1221 Heat-resistant steel bars
GB/T 3077 Alloy structure steels
GB/T 3965 Determination of diffusible hydrogen in deposited metal
GB/T 4226 Cold finished stainless steel bar
GB/T 4334 Corrosion of metals and alloys - Test methods for intergranular corrosion of austenitic and ferritic-austenitic (duplex) stainless steels
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 6479 Seamless steel tubes for high-pressure chemical fertilizer equipments
GB/T 6803 Test method for drop-weight test to determine nil-ductility transition temperature of ferritic steels
GB/T 7735-2016 Automated eddy current testing of seamless and welded (except submerged arc-welded) steel tubes for detection of imperfections
GB/T 9948 Seamless steel tubes for petroleum cracking
GB/T 13305 Micrographic method for determining area content of the α-phases in stainless steels
GB/T 20878 Stainless and heat-resisting steels - Designation and chemical composition
GB/T 21433 Detecting susceptibility to intergranular corrosion in stainless steel pressure vessels
GB/T 31935 Corrosion of metals and alloys - Corrosion test for intergranular corrosion susceptibility of low-Cr ferritic stainless steels
GB/T 32571 Corrosion of metals and alloys - Corrosion test for intergranular corrosion susceptibility of high-Cr ferritic stainless steels
GB/T 39255 Gases and gas mixtures for welding and cutting processes
JB/T 4756 Nickel and nickel alloy pressure vessels
NB/T 47002.1 Clad plate for pressure vessel - Part 1: Stainless steel-steel clad plate
NB/T 47002.2 Clad plate for pressure vessel - Part 2: Nickel-steel clad plate
NB/T 47002.3 Clad plate for pressure vessel - Part 3: Titanium-steel clad plate
NB/T 47002.4 Clad plate for pressure vessel - Part 4: Copper-steel clad plate
NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment
NB/T 47013.2-2015 Nondestructive testing of pressure equipments - Part 2: Radiographic testing
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
NB/T 47014 Welding procedure qualification for pressure equipment
NB/T 47018.1 Technical permission of welding materials for pressure equipment - Part 1: General rule
NB/T 47018.2 Technical permission of welding materials for pressure equipment - Section 2: Electrodes for steel
NB/T 47018.3 Technical permission of welding materials for pressure equipment - Section 3: Steel electrodes and rods for gas shielded arc welding
NB/T 47018.4 Technical permission of welding materials for pressure equipment - Section 4: Electrodes and fluxes for submerged arc welding
NB/T 47018.5 Technical permission of welding materials for pressure equipment - Section 5: Stainless steel strip electrodes and fluxes for overlay welding
NB/T 47019.1 Purchase technical specification for boiler & heat exchanger tubes - .Part 1: General requirements
NB/T 47019.4 Purchase technical specification for boiler & heat exchanger tubes. - Part 4: Low alloy steel for low-temperature service
TSG 21 Supervision regulation on safety technology for stationary pressure vessel
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 150.1 apply.
4 General requirements
4.1 This document specifies relevant provisions on steel materials and welding materials for steel plates, steel pipes, steel forgings, steel studs (including bolts) for pressure parts of pressure vessels.
4.2 The steel materials used for pressure parts of pressure vessels shall be steel materials with good weldability, and the steel materials used for non-pressure parts welded with pressure parts shall also be steel materials with good weldability.
4.3 It is allowed to apply austenitic stainless steel materials not listed in this document but listed in GB/T 20878 and GB/T 713.7, but their technical requirements (e.g., phosphorus and sulfur content, strength indicators) shall not be lower than the provisions of similar grades of chemical composition in the corresponding steel material standards listed in this document.
4.4 When the steel materials (except steel materials that meet the requirements of 4.3) not listed in this document are applied, their technical requirements shall comply with Annex A.
4.5 The steel materials for pressure parts of pressure vessels shall be accompanied by the steel material quality certificate of the steel material manufacturer. The contents of the quality certificate (including the heat treatment process parameters of the delivery status of the steel materials when necessary) shall be complete and clear, and the traceable information mark shall be printed, and affixed with the quality inspection seal of the material manufacturer. The traceable information includes the name of the steel material manufacturer, steel material standard No., brand, specification, furnace batch No., delivery status, heat treatment process parameters (when necessary), issuance date of quality certificate, etc. Traceable information marks include QR codes or barcodes.
4.6 The vessel manufacturer shall perform acceptance inspection on the steel materials according to the quality certificate. In case of no original steel material quality certificate from the steel material manufacturer, the official seal of the material operation organization and the signature (seal) of the person in charge of the handling shall be affixed on the photocopy of the original steel material quality certificate.
4.7 The selection of steel materials for pressure parts of pressure vessels shall be based on the service conditions (e.g., design temperature, design pressure, medium characteristics and operating characteristics, etc.) of the vessels, the chemical composition, microstructure, properties (mechanical properties, process properties, chemical properties and physical properties) of the steel materials, the manufacturing process of the vessels, as well as the economic rationality.
4.8 The steel materials for pressure parts of pressure vessels shall be smelted in oxygen converter or electric furnace, or by electroslag remelting method. As for the low-alloy steel plates and low-alloy steel forgings, austenitic-ferritic stainless steel plates with the lower limit of standard tensile strength greater than 540 MPa, as well as the low-temperature steel plates, low-temperature steel forgings and low-temperature-steel pipes with the service temperature below -20°C, they shall also be refined outside the furnace.
4.9 The upper service temperature limit of the steel materials for pressure parts of pressure vessels shall meet the following requirements.
a) The upper service temperature limit of steel material is the maximum temperature corresponding to the allowable stress of each grade of steel materials in Tables C.1 to C.8 (the allowable stress on the right side of the thick line in the allowable stress table is determined by the average value of the 105 h high-temperature durable strength limit of the steel materials). If the steel materials need be operated above the upper limit of service temperature for a short time due to the process requirements, it shall be specified in the design documents.
b) As for the non-alloy steel materials and carbon manganese steel materials, when the materials are applied at temperatures higher than 425°C for a long time, attention shall be paid to the graphitization tendency of the carbide phase in the steel.
c) When the service temperature of austenitic stainless steel materials is higher than 525°C, the carbon content in the steel shall not be less than 0.04%.
4.10 The lower service temperature limit of steel for pressure parts of pressure vessels shall meet the following requirements.
a) The lower operating temperature limit of steel materials shall be as specified in Clauses 5 to 8.
b) The lower service temperature limit of austenitic stainless steel materials is -269°C. When the operating temperature is higher than or equal to -196°C, the impact test may be exempted. If the operating temperature is lower than -196°C, the low-temperature impact test shall be conducted at the design temperature of the pressure vessel. The average value of impact absorption energy of the 3 standard specimens, is no less than 54 J and the average value of the lateral expansion, , is no less than 0.53 mm. Austenitic-ferritic stainless steel materials may be subjected to the impact test with the lowest impact test temperature of -40°C. The average value of impact absorption energy of the 3 standard specimens, , is no less than 54 J and the average value of the lateral expansion, , is no less than 0.53 mm. Other requirements for impact test shall be as specified in 4.11 b).
c) The special technical requirements for austenitic stainless steel materials (steel plates, steel pipes, steel forgings) for low-temperature liquid hydrogen and liquid helium pressure vessels comply with the following provisions.
1) The ferrite content of austenitic stainless steel materials is determined according to GB/T 13305, and shall not be greater than 3%.
2) The austenite stability coefficient calculated from the measured value of chemical composition in the quality certificate of austenitic stainless steel materials, Δ, is no less than 0, where Δ=Ni+0.5Mn+35C-0.0833(Cr+1.5Mo-20)2-12.
3) The low-temperature martensitic transformation temperature of the measured value of chemical composition in the quality certificate of austenitic stainless steel material, Ms, is no greater than -253°C or -269°C, where Ms(°C)={75(14.6-Cr)+110 (8.9-Ni)+60(1.33-Mn)+50 (0.47-Si)+3000 × [0.068-(C+N)] -32}/1.8.
4) Austenitic stainless steel materials for liquid hydrogen pressure vessels shall be subjected to the impact test at -253°C, and austenitic stainless steel materials for liquid helium pressure vessels shall be subjected to the impact test at -269°C. The impact performance indicators shall be as specified in 4.10b). Austenitic stainless steel materials for liquid hydrogen pressure vessels and liquid helium pressure vessels may also be subjected to the impact test at -196°C. The average value of impact absorption energy and the average value of the lateral expansion of 3 standard specimens, and shall be no less than 70 J and 0.76 mm respectively. Other requirements for the impact test shall be as specified in 4.11 b).
d) For steel materials applied under low-temperature and low stress working conditions, the lower limit of its service temperature shall comply with GB/T 150.3.
4.11 The impact test of non-alloy steel materials and alloy steel materials shall comply with the following provisions.
a) The impact performance indicators of non-alloy steel materials and alloy steel materials (steel plates, steel pipes, steel forgings) shall be as specified in Table 1. For steel materials whose lower limit of standard tensile strength decreases with the increase of thickness, the lower limit of standard tensile strength in Table 1 is the lower limit of standard tensile strength of the minimum thickness of steel materials.
Table 1 Impact performance indicators of non-alloy steel materials and alloy steel materials
Lower limit of standard tensile strength of steel materials, (Rm)
Pa Average value of impact absorption energy of 3 standard specimens, ( )
J Average value of lateral expansion of 3 standard specimens, ( )
mm
≤450 ≥20 -
>450~510 ≥24 -
>510~570 ≥31 -
>570~630 ≥34 -
>630~690 ≥38 ≥0.53
>690 ≥47 ≥0.53
b) The sampling position and direction of the Charpy V-notch impact specimens shall comply with the corresponding steel material standards, and priority shall be given to selecting standard specimens with a thickness of 10 mm. Three standard specimens are taken from each group for the impact test, and the impact absorption energy value and lateral expansion value of 1 standard specimen may be lower than the specified value in Table 1, but shall not be lower than 70% of the specified value in Table 1. When the impact test results fail to meet the above requirements, 3 standard specimens shall be taken from the same position and direction of the steel materials for retest. The average impact absorption energy value and lateral expansion value of the 6 standard specimens in the former group and the latter group shall not be lower than the specified values in Table 1. The value of 2 standard specimens may be lower than the specified value, but the value of only 1 specimen may be lower than 70% of the specified value.
c) When the steel materials cannot be adopted to prepare standard specimens (with a thickness less than 11 mm), small-sized specimens with a thickness of 7.5 mm or 5 mm shall be prepared sequentially. The average value of their impact absorption energy shall be 75% or 50% of the average value of the impact absorption energy of the standard specimens, respectively. The requirements for the impact absorption energy value of a single standard specimen shall be as specified in 4.11b). When standard specimens can be prepared from steel materials and the small-size specimens with a thickness of 7.5 mm or 5mm are prepared, their impact test temperature shall be reduced by 5°C and 10°C respectively (except for steel materials with impact test temperature below -100°C); the average value of their impact absorption energy is 75% or 50% of the average value of the impact absorption energy of the standard specimens, respectively; the requirements for impact absorption energy value of a single standard specimen shall be as specified in 4.11b).
d) In steel material standards, the average value of impact absorption energy and the average value of the lateral expansion of steel materials, if higher than those specified in Table 1, shall also comply with the corresponding steel material standards.
e) The lateral expansion value of Charpy impact specimen is determined according to the provisions of GB/T 229, and the qualified indicator of the lateral expansion value of the impact specimens has nothing to do with the size of the impact specimens.
f) The transition temperature Tt of low-alloy steel plates and forgings with impact test temperature ranging from -40°C to -100°C may be measured according to GB/T 229 (e.g., the transition temperature Tt47 determined by the designated absorption energy value, 47 J, the transition temperature Tt50%US determined by 50% of upper plateau of absorption energy, the transition temperature Tt0.53 determined by the value of designated lateral expansion, 0.53 mm, or the transition temperature Tt50%SFA determined by 50% of the designated shear cross section).
g) The impact test requirements of steel plates shall be as specified in Clause 5. For Q245R, Q345R and 13MnNiMoR steel plates, if the impact test at -20°C is required, it shall be indicated in the design documents. If it is necessary to improve the impact energy absorption indicator and the lateral expansion value of steel plates, it shall be specified in the design document.
h) The impact test requirements for steel pipes shall be as specified in Clause 6.
i) The impact test requirements of steel forgings shall be as specified in Clause 7. For 20, 16Mn, 20MnMo and 20MnMoNb steel forgings, in case of need for the impact test at -20°C, it shall be indicated in the design documents. In case of need for improving the impact energy absorption indicator and expansion value of steel forgings, it shall be specified in the design document.
j) The impact test requirements for non-alloy steel, low-alloy steel, and heat-resistant steel bars shall be as specified in Clause 8.
k) The impact test requirements for welding materials shall be as specified in Clause 9.
4.12 Steel materials may be subjected to stress corrosion test according to GB/T 15970.1~GB/T 15970.9 or GB/T 4157, or pitting corrosion test according to GB/T 17897. The specific test methods and qualification indicators shall be as specified in the design documents.
4.13 The phase ratio of austenitic-ferritic stainless steel plates, forgings and steel pipes shall be determined according to GB/T 13305. The metallographic structure shall be austenitic-ferrite, and the austenite content shall be 40% ~ 60% (ferrite shall be 60% ~ 40%).
4.14 In case of special technical requirements for steel materials (e.g., requiring special smelting methods, strict chemical composition, high impact absorption energy indicators or lateral expansion values, additional guaranteed high temperature yield strength and tensile strength, improving non-destructive test qualification grades, increasing mechanical properties inspection rates, etc.), they shall be specified in the design documents.
4.15 Among the steel materials used for the main pressure parts, steel materials not listed in this document, nor listed in the national standards for special steel plates for pressure vessels (pressure equipment), professional standards for special forgings and professional standards for special clad steel plates shall be subjected to technical review according to TSG 21 before the steel materials may be applied for manufacturing pressure vessels.
Note: The national standards for special steel plates for pressure vessels (pressure equipment) include GB/T 713.1, GB/T 713.2, GB/T 713.3, GB/T 713.4, GB/T 713.6 and GB/T 713.7. The professional standards for special forgings include NB/T 47008, NB/T 47009 and NB/T 47010, and the professional standards for special clad steel plates include NB/T 47002.1, NB/T 47002.2, NB/T 47002.3 and NB/T 47002.4.
4.16 As for the steel materials for the main pressure parts (excluding austenitic stainless steel materials), which are not included in this document but have been included in the national standards for special steel plates for pressure vessels (pressure equipment), the professional standards for special forgings, and the professional standards for special clad steel plates, the material development organization shall develop corporate standards and publicly disclose them to the public in accordance with relevant provisions, providing necessary material data (including chemical composition, tensile properties, fatigue test data, fracture toughness, and other corresponding performance parameters that meet the requirements of the material's scope of application). The materials shall be tested and verified by the type test institution for pressure vessel materials (steel plates, forgings) to prove that their various performance indicators meet the requirements of this document, and the materials may be applied for manufacturing the pressure vessels.
4.17 For alloy steel plates and forgings (excluding austenitic stainless steel materials) with a lower limit of standard tensile strength greater than 540 Ma or the design temperatures below -40°C in this document, the material manufacturer shall make them meet the requirements of both a) and b) during the first manufacture and prove that their performance indicators meet the requirements of this document and the materials may be applied manufacturing the pressure vessels.
a) Steel material manufacturers shall provide technical information such as material weldability test reports and post-weld heat treatment processes to steel material application organizations, and provide high-temperature short-term tensile properties, fatigue test data, fracture toughness, and a series of test data to determine the results of drop weight test (DWT) and ductile brittle transition temperature (Tt50%US) according to design needs. If the operating temperature is higher than the creep temperature of the materials, the steel material manufacturers shall provide the high-temperature performance test data (yield strength, durability strength, creep limit, etc.) of the steel materials.
b) Steel materials shall be tested and verified by a type test institution for the pressure vessel materials (steel plates, forgings).
4.18 As for the steel plates and forgings for the main pressure parts of pressure vessels, which have been included in this document but the plate thickness or nominal forging thickness of which exceeds the range specified in this document, their various properties shall not be lower than the minimum requirements within the thickness range specified in this document. The pressure vessel design organization shall put forward the technical conditions for material ordering that the above steel materials meet the design requirements, and the pressure vessel manufacturer shall conduct material re-inspection to prove that all properties of the materials meet the minimum requirements and technical conditions for material ordering within the thickness range specified in the material standard of the same grade, and the materials may be applied for manufacturing the pressure vessels.
4.19 When selecting steel materials as specified in 4.15, 4.16, and 4.18 of this document, the design organization shall provide specific instructions in the design document that the material selection meets the basic safety requirements of TSG 21, including the mechanical properties, physical properties, process properties, and compatibility with the medium of the materials, and meanwhile, the organization shall raise the technical conditions for material ordering, and clarify the relevant technical requirements for pressure vessel manufacture, application, inspection, etc.; and the organization shall also be responsible for the material selection.
4.20 When selecting steel materials as specified in 4.15, 4.16, and 4.18 for the main pressure parts of pressure vessels, the pressure vessel manufacturer shall conduct a confirmatory retest of its chemical composition (by furnace No.) and mechanical properties (by batch No.). After the retest results are confirmed to be qualified by the supervision and inspection agency, the materials may be put into application. The material retest report shall be included in the product quality supporting documents.
4.21 As for the provisions for the application of the steel materials for the main pressure parts, the steel materials that have been included in this document but not in the national standards for special steel plates for pressure vessels (pressure equipment), professional standards for special forgings, professional standards for special clad steel plates, and national standards or professional standards for steel pipes (except for steel materials as specified in 4.3), as well as the foreign grades of steel materials, their technical requirements shall be as specified in Annex A.
4.22 The pressure vessel manufacturers or the on-site welding organization shall obtain written approval from the original design organization for the substitution of the steel materials for pressure parts, and make detailed records on the as built drawings.
4.23 The to-be-met technical requirements for steel materials to be incorporated into this document are as specified in Annex B.
4.24 The allowable stress of each steel material shall be determined according to TSG 21 and GB/T 150.1, and the allowable stress of each steel material shall be determined as specified in Tables C.1 to Table C.8. The allowable stress at the middle temperature of each steel material in the allowable stress table may be obtained by interpolation method.
4.25 The application provisions of Q235 series steel plates shall be as specified in Annex D.
4.26 As for the steel materials, the high-temperature yield strength, and the average high-temperature endurance strength limit are shown in Tables E.1 to E.8, and Tables E.9 to E.12 respectively, while the elastic modulus and the average linear expansion coefficient are shown in Tables E.13 and E.14 respectively.
4.27 The approximate comparison of high-alloy steel grades is shown in Table F.1.
5 Steel plate
5.1 Non-alloy steel plates and alloy steel plates
5.1.1 As for the service status, thickness, upper service temperature limit and allowable stress of the steel plates in GB/T 713.1, GB/T 713.2, GB/T 713.3, GB/T 713.4 and GB/T 713.6, the relevant provisions in Table C.1 shall prevail.
5.1.2 All steel plates rolled from continuous casting billets or steel ingots in Table C1 shall have a compression ratio not less than 3.0, and steel plates rolled from directionally solidified steel billets shall have a compression ratio not less than 2.4. The steel plates rolled by electroslag remelting billet shall have a compression ratio not less than 2.0.
5.1.3 The steel plates delivered by the steel plate manufacturers shall be supplied in the service state as shown in Table C.1.
5.1.4 The following non-alloy and low-alloy steel plates shall be put into application under as-normalized condition.
a) Q245R, GB/SA516 Gr 485 and Q345R ones for cylinders of multilayer vessels;
b) Q245R, GB/SA516 Gr 485 and Q345R ones with thickness greater than 36 mm for housing;
c) Q245R, GB/SA516 Gr485 and Q345R ones with a thickness greater than 60 mm for other pressure parts (flanges, tube plates, flat covers, etc.)
d) Q345R ones with a thickness greater than 50 mm, the as-normalized and tempered condition of which may replace the as-normalized condition.
5.1.5 The following non-alloy steel plates and alloy steel plates shall be subjected to tensile and V-notch impact tests plate by plate (plate for heat treatment) (the impact test temperature shall be as specified in the corresponding steel plate standards):
a) quenched-tempered heat treatment steel plates;
b) cylinder steel plates of multilayer vessels;
c) steel plates with a housing thickness greater than 60 mm.
5.1.6 For steel plates for housings with a thickness greater than 36 mm under quenched-tempered condition and with a thickness greater than 80 mm under as-normalized condition or as-normalized and tempered condition, a set of impact tests on the specimens taken at 1/2 of the thickness may be added. The impact test temperature shall comply with the corresponding steel plate standards, and the impact performance indicators shall be as specified in Table 1. If the impact performance indicators of the specimens taken at 1/2 of positions in GB/T 713.1, GB/T 713.2, GB/T 713.3, GB/T 713.4, and GB/T 713.6 are higher than those specified in Table 1, they shall also comply with the corresponding steel material standards.
Foreword I
Introduction III
1 Scope
3 Terms and definitions
4 General requirements
5 Steel plate
6 Steel tube
7 Steel forgings
8 Steel bars for studs (including bolts) and nuts
9 Welding materials
Annex A (Normative) Supplementary requirements for steel
Annex B (Normative) Technical requirements shall be met for steels included in this document
Annex C (Normative) Allowable stress of steels
Annex D (Normative) Provisions on the use of Q235 series steel plates
Annex E (Informative) High-temperature yield strength, average of high-temperature endurance strength limit, elastic modulus and average coefficient of linear expansion of steels
Annex F (Informative) Approximate comparison of high alloy steel designations
Bibliography
GB/T 150.2-2024 Pressure vessels - Part 2: Materials
1 Scope
This document specifies the allowable grades and standards of steel materials for pressure parts of steel pressure vessels, the additional technical requirements of steel materials, the application scope (temperature and pressure) of steel materials, the allowable stress of steel materials, and the basic requirements of welding materials.
This document is applicable to the pressure vessels with design temperature of -269°C ~ 800°C and the design pressure not greater than 35 MPa.
This document is not applicable to the scope of inapplicability specified in GB/T 150.1.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 150.1 Pressure vessels - Part 1: General requirements
GB/T 150.3 Pressure vessels - Part 3: Design
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 699 Quality carbon structure steels
GB/T 700 Carbon structural steels
GB/T 709 Dimension, shape, weight and tolerance for hot-rolled steel strip, plate and sheet
GB/T 713.7 Steel plate, sheet and strip for pressure equipments - Part 7: Stainless steel and heat resisting steel
GB/T 1220 Stainless steel bars
GB/T 1221 Heat-resistant steel bars
GB/T 3077 Alloy structure steels
GB/T 3965 Determination of diffusible hydrogen in deposited metal
GB/T 4226 Cold finished stainless steel bar
GB/T 4334 Corrosion of metals and alloys - Test methods for intergranular corrosion of austenitic and ferritic-austenitic (duplex) stainless steels
GB/T 6394 Determination of estimating the average grain size of metal
GB/T 6479 Seamless steel tubes for high-pressure chemical fertilizer equipments
GB/T 6803 Test method for drop-weight test to determine nil-ductility transition temperature of ferritic steels
GB/T 7735-2016 Automated eddy current testing of seamless and welded (except submerged arc-welded) steel tubes for detection of imperfections
GB/T 9948 Seamless steel tubes for petroleum cracking
GB/T 13305 Micrographic method for determining area content of the α-phases in stainless steels
GB/T 20878 Stainless and heat-resisting steels - Designation and chemical composition
GB/T 21433 Detecting susceptibility to intergranular corrosion in stainless steel pressure vessels
GB/T 31935 Corrosion of metals and alloys - Corrosion test for intergranular corrosion susceptibility of low-Cr ferritic stainless steels
GB/T 32571 Corrosion of metals and alloys - Corrosion test for intergranular corrosion susceptibility of high-Cr ferritic stainless steels
GB/T 39255 Gases and gas mixtures for welding and cutting processes
JB/T 4756 Nickel and nickel alloy pressure vessels
NB/T 47002.1 Clad plate for pressure vessel - Part 1: Stainless steel-steel clad plate
NB/T 47002.2 Clad plate for pressure vessel - Part 2: Nickel-steel clad plate
NB/T 47002.3 Clad plate for pressure vessel - Part 3: Titanium-steel clad plate
NB/T 47002.4 Clad plate for pressure vessel - Part 4: Copper-steel clad plate
NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment
NB/T 47013.2-2015 Nondestructive testing of pressure equipments - Part 2: Radiographic testing
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
NB/T 47014 Welding procedure qualification for pressure equipment
NB/T 47018.1 Technical permission of welding materials for pressure equipment - Part 1: General rule
NB/T 47018.2 Technical permission of welding materials for pressure equipment - Section 2: Electrodes for steel
NB/T 47018.3 Technical permission of welding materials for pressure equipment - Section 3: Steel electrodes and rods for gas shielded arc welding
NB/T 47018.4 Technical permission of welding materials for pressure equipment - Section 4: Electrodes and fluxes for submerged arc welding
NB/T 47018.5 Technical permission of welding materials for pressure equipment - Section 5: Stainless steel strip electrodes and fluxes for overlay welding
NB/T 47019.1 Purchase technical specification for boiler & heat exchanger tubes - .Part 1: General requirements
NB/T 47019.4 Purchase technical specification for boiler & heat exchanger tubes. - Part 4: Low alloy steel for low-temperature service
TSG 21 Supervision regulation on safety technology for stationary pressure vessel
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 150.1 apply.
4 General requirements
4.1 This document specifies relevant provisions on steel materials and welding materials for steel plates, steel pipes, steel forgings, steel studs (including bolts) for pressure parts of pressure vessels.
4.2 The steel materials used for pressure parts of pressure vessels shall be steel materials with good weldability, and the steel materials used for non-pressure parts welded with pressure parts shall also be steel materials with good weldability.
4.3 It is allowed to apply austenitic stainless steel materials not listed in this document but listed in GB/T 20878 and GB/T 713.7, but their technical requirements (e.g., phosphorus and sulfur content, strength indicators) shall not be lower than the provisions of similar grades of chemical composition in the corresponding steel material standards listed in this document.
4.4 When the steel materials (except steel materials that meet the requirements of 4.3) not listed in this document are applied, their technical requirements shall comply with Annex A.
4.5 The steel materials for pressure parts of pressure vessels shall be accompanied by the steel material quality certificate of the steel material manufacturer. The contents of the quality certificate (including the heat treatment process parameters of the delivery status of the steel materials when necessary) shall be complete and clear, and the traceable information mark shall be printed, and affixed with the quality inspection seal of the material manufacturer. The traceable information includes the name of the steel material manufacturer, steel material standard No., brand, specification, furnace batch No., delivery status, heat treatment process parameters (when necessary), issuance date of quality certificate, etc. Traceable information marks include QR codes or barcodes.
4.6 The vessel manufacturer shall perform acceptance inspection on the steel materials according to the quality certificate. In case of no original steel material quality certificate from the steel material manufacturer, the official seal of the material operation organization and the signature (seal) of the person in charge of the handling shall be affixed on the photocopy of the original steel material quality certificate.
4.7 The selection of steel materials for pressure parts of pressure vessels shall be based on the service conditions (e.g., design temperature, design pressure, medium characteristics and operating characteristics, etc.) of the vessels, the chemical composition, microstructure, properties (mechanical properties, process properties, chemical properties and physical properties) of the steel materials, the manufacturing process of the vessels, as well as the economic rationality.
4.8 The steel materials for pressure parts of pressure vessels shall be smelted in oxygen converter or electric furnace, or by electroslag remelting method. As for the low-alloy steel plates and low-alloy steel forgings, austenitic-ferritic stainless steel plates with the lower limit of standard tensile strength greater than 540 MPa, as well as the low-temperature steel plates, low-temperature steel forgings and low-temperature-steel pipes with the service temperature below -20°C, they shall also be refined outside the furnace.
4.9 The upper service temperature limit of the steel materials for pressure parts of pressure vessels shall meet the following requirements.
a) The upper service temperature limit of steel material is the maximum temperature corresponding to the allowable stress of each grade of steel materials in Tables C.1 to C.8 (the allowable stress on the right side of the thick line in the allowable stress table is determined by the average value of the 105 h high-temperature durable strength limit of the steel materials). If the steel materials need be operated above the upper limit of service temperature for a short time due to the process requirements, it shall be specified in the design documents.
b) As for the non-alloy steel materials and carbon manganese steel materials, when the materials are applied at temperatures higher than 425°C for a long time, attention shall be paid to the graphitization tendency of the carbide phase in the steel.
c) When the service temperature of austenitic stainless steel materials is higher than 525°C, the carbon content in the steel shall not be less than 0.04%.
4.10 The lower service temperature limit of steel for pressure parts of pressure vessels shall meet the following requirements.
a) The lower operating temperature limit of steel materials shall be as specified in Clauses 5 to 8.
b) The lower service temperature limit of austenitic stainless steel materials is -269°C. When the operating temperature is higher than or equal to -196°C, the impact test may be exempted. If the operating temperature is lower than -196°C, the low-temperature impact test shall be conducted at the design temperature of the pressure vessel. The average value of impact absorption energy of the 3 standard specimens, is no less than 54 J and the average value of the lateral expansion, , is no less than 0.53 mm. Austenitic-ferritic stainless steel materials may be subjected to the impact test with the lowest impact test temperature of -40°C. The average value of impact absorption energy of the 3 standard specimens, , is no less than 54 J and the average value of the lateral expansion, , is no less than 0.53 mm. Other requirements for impact test shall be as specified in 4.11 b).
c) The special technical requirements for austenitic stainless steel materials (steel plates, steel pipes, steel forgings) for low-temperature liquid hydrogen and liquid helium pressure vessels comply with the following provisions.
1) The ferrite content of austenitic stainless steel materials is determined according to GB/T 13305, and shall not be greater than 3%.
2) The austenite stability coefficient calculated from the measured value of chemical composition in the quality certificate of austenitic stainless steel materials, Δ, is no less than 0, where Δ=Ni+0.5Mn+35C-0.0833(Cr+1.5Mo-20)2-12.
3) The low-temperature martensitic transformation temperature of the measured value of chemical composition in the quality certificate of austenitic stainless steel material, Ms, is no greater than -253°C or -269°C, where Ms(°C)={75(14.6-Cr)+110 (8.9-Ni)+60(1.33-Mn)+50 (0.47-Si)+3000 × [0.068-(C+N)] -32}/1.8.
4) Austenitic stainless steel materials for liquid hydrogen pressure vessels shall be subjected to the impact test at -253°C, and austenitic stainless steel materials for liquid helium pressure vessels shall be subjected to the impact test at -269°C. The impact performance indicators shall be as specified in 4.10b). Austenitic stainless steel materials for liquid hydrogen pressure vessels and liquid helium pressure vessels may also be subjected to the impact test at -196°C. The average value of impact absorption energy and the average value of the lateral expansion of 3 standard specimens, and shall be no less than 70 J and 0.76 mm respectively. Other requirements for the impact test shall be as specified in 4.11 b).
d) For steel materials applied under low-temperature and low stress working conditions, the lower limit of its service temperature shall comply with GB/T 150.3.
4.11 The impact test of non-alloy steel materials and alloy steel materials shall comply with the following provisions.
a) The impact performance indicators of non-alloy steel materials and alloy steel materials (steel plates, steel pipes, steel forgings) shall be as specified in Table 1. For steel materials whose lower limit of standard tensile strength decreases with the increase of thickness, the lower limit of standard tensile strength in Table 1 is the lower limit of standard tensile strength of the minimum thickness of steel materials.
Table 1 Impact performance indicators of non-alloy steel materials and alloy steel materials
Lower limit of standard tensile strength of steel materials, (Rm)
Pa Average value of impact absorption energy of 3 standard specimens, ( )
J Average value of lateral expansion of 3 standard specimens, ( )
mm
≤450 ≥20 -
>450~510 ≥24 -
>510~570 ≥31 -
>570~630 ≥34 -
>630~690 ≥38 ≥0.53
>690 ≥47 ≥0.53
b) The sampling position and direction of the Charpy V-notch impact specimens shall comply with the corresponding steel material standards, and priority shall be given to selecting standard specimens with a thickness of 10 mm. Three standard specimens are taken from each group for the impact test, and the impact absorption energy value and lateral expansion value of 1 standard specimen may be lower than the specified value in Table 1, but shall not be lower than 70% of the specified value in Table 1. When the impact test results fail to meet the above requirements, 3 standard specimens shall be taken from the same position and direction of the steel materials for retest. The average impact absorption energy value and lateral expansion value of the 6 standard specimens in the former group and the latter group shall not be lower than the specified values in Table 1. The value of 2 standard specimens may be lower than the specified value, but the value of only 1 specimen may be lower than 70% of the specified value.
c) When the steel materials cannot be adopted to prepare standard specimens (with a thickness less than 11 mm), small-sized specimens with a thickness of 7.5 mm or 5 mm shall be prepared sequentially. The average value of their impact absorption energy shall be 75% or 50% of the average value of the impact absorption energy of the standard specimens, respectively. The requirements for the impact absorption energy value of a single standard specimen shall be as specified in 4.11b). When standard specimens can be prepared from steel materials and the small-size specimens with a thickness of 7.5 mm or 5mm are prepared, their impact test temperature shall be reduced by 5°C and 10°C respectively (except for steel materials with impact test temperature below -100°C); the average value of their impact absorption energy is 75% or 50% of the average value of the impact absorption energy of the standard specimens, respectively; the requirements for impact absorption energy value of a single standard specimen shall be as specified in 4.11b).
d) In steel material standards, the average value of impact absorption energy and the average value of the lateral expansion of steel materials, if higher than those specified in Table 1, shall also comply with the corresponding steel material standards.
e) The lateral expansion value of Charpy impact specimen is determined according to the provisions of GB/T 229, and the qualified indicator of the lateral expansion value of the impact specimens has nothing to do with the size of the impact specimens.
f) The transition temperature Tt of low-alloy steel plates and forgings with impact test temperature ranging from -40°C to -100°C may be measured according to GB/T 229 (e.g., the transition temperature Tt47 determined by the designated absorption energy value, 47 J, the transition temperature Tt50%US determined by 50% of upper plateau of absorption energy, the transition temperature Tt0.53 determined by the value of designated lateral expansion, 0.53 mm, or the transition temperature Tt50%SFA determined by 50% of the designated shear cross section).
g) The impact test requirements of steel plates shall be as specified in Clause 5. For Q245R, Q345R and 13MnNiMoR steel plates, if the impact test at -20°C is required, it shall be indicated in the design documents. If it is necessary to improve the impact energy absorption indicator and the lateral expansion value of steel plates, it shall be specified in the design document.
h) The impact test requirements for steel pipes shall be as specified in Clause 6.
i) The impact test requirements of steel forgings shall be as specified in Clause 7. For 20, 16Mn, 20MnMo and 20MnMoNb steel forgings, in case of need for the impact test at -20°C, it shall be indicated in the design documents. In case of need for improving the impact energy absorption indicator and expansion value of steel forgings, it shall be specified in the design document.
j) The impact test requirements for non-alloy steel, low-alloy steel, and heat-resistant steel bars shall be as specified in Clause 8.
k) The impact test requirements for welding materials shall be as specified in Clause 9.
4.12 Steel materials may be subjected to stress corrosion test according to GB/T 15970.1~GB/T 15970.9 or GB/T 4157, or pitting corrosion test according to GB/T 17897. The specific test methods and qualification indicators shall be as specified in the design documents.
4.13 The phase ratio of austenitic-ferritic stainless steel plates, forgings and steel pipes shall be determined according to GB/T 13305. The metallographic structure shall be austenitic-ferrite, and the austenite content shall be 40% ~ 60% (ferrite shall be 60% ~ 40%).
4.14 In case of special technical requirements for steel materials (e.g., requiring special smelting methods, strict chemical composition, high impact absorption energy indicators or lateral expansion values, additional guaranteed high temperature yield strength and tensile strength, improving non-destructive test qualification grades, increasing mechanical properties inspection rates, etc.), they shall be specified in the design documents.
4.15 Among the steel materials used for the main pressure parts, steel materials not listed in this document, nor listed in the national standards for special steel plates for pressure vessels (pressure equipment), professional standards for special forgings and professional standards for special clad steel plates shall be subjected to technical review according to TSG 21 before the steel materials may be applied for manufacturing pressure vessels.
Note: The national standards for special steel plates for pressure vessels (pressure equipment) include GB/T 713.1, GB/T 713.2, GB/T 713.3, GB/T 713.4, GB/T 713.6 and GB/T 713.7. The professional standards for special forgings include NB/T 47008, NB/T 47009 and NB/T 47010, and the professional standards for special clad steel plates include NB/T 47002.1, NB/T 47002.2, NB/T 47002.3 and NB/T 47002.4.
4.16 As for the steel materials for the main pressure parts (excluding austenitic stainless steel materials), which are not included in this document but have been included in the national standards for special steel plates for pressure vessels (pressure equipment), the professional standards for special forgings, and the professional standards for special clad steel plates, the material development organization shall develop corporate standards and publicly disclose them to the public in accordance with relevant provisions, providing necessary material data (including chemical composition, tensile properties, fatigue test data, fracture toughness, and other corresponding performance parameters that meet the requirements of the material's scope of application). The materials shall be tested and verified by the type test institution for pressure vessel materials (steel plates, forgings) to prove that their various performance indicators meet the requirements of this document, and the materials may be applied for manufacturing the pressure vessels.
4.17 For alloy steel plates and forgings (excluding austenitic stainless steel materials) with a lower limit of standard tensile strength greater than 540 Ma or the design temperatures below -40°C in this document, the material manufacturer shall make them meet the requirements of both a) and b) during the first manufacture and prove that their performance indicators meet the requirements of this document and the materials may be applied manufacturing the pressure vessels.
a) Steel material manufacturers shall provide technical information such as material weldability test reports and post-weld heat treatment processes to steel material application organizations, and provide high-temperature short-term tensile properties, fatigue test data, fracture toughness, and a series of test data to determine the results of drop weight test (DWT) and ductile brittle transition temperature (Tt50%US) according to design needs. If the operating temperature is higher than the creep temperature of the materials, the steel material manufacturers shall provide the high-temperature performance test data (yield strength, durability strength, creep limit, etc.) of the steel materials.
b) Steel materials shall be tested and verified by a type test institution for the pressure vessel materials (steel plates, forgings).
4.18 As for the steel plates and forgings for the main pressure parts of pressure vessels, which have been included in this document but the plate thickness or nominal forging thickness of which exceeds the range specified in this document, their various properties shall not be lower than the minimum requirements within the thickness range specified in this document. The pressure vessel design organization shall put forward the technical conditions for material ordering that the above steel materials meet the design requirements, and the pressure vessel manufacturer shall conduct material re-inspection to prove that all properties of the materials meet the minimum requirements and technical conditions for material ordering within the thickness range specified in the material standard of the same grade, and the materials may be applied for manufacturing the pressure vessels.
4.19 When selecting steel materials as specified in 4.15, 4.16, and 4.18 of this document, the design organization shall provide specific instructions in the design document that the material selection meets the basic safety requirements of TSG 21, including the mechanical properties, physical properties, process properties, and compatibility with the medium of the materials, and meanwhile, the organization shall raise the technical conditions for material ordering, and clarify the relevant technical requirements for pressure vessel manufacture, application, inspection, etc.; and the organization shall also be responsible for the material selection.
4.20 When selecting steel materials as specified in 4.15, 4.16, and 4.18 for the main pressure parts of pressure vessels, the pressure vessel manufacturer shall conduct a confirmatory retest of its chemical composition (by furnace No.) and mechanical properties (by batch No.). After the retest results are confirmed to be qualified by the supervision and inspection agency, the materials may be put into application. The material retest report shall be included in the product quality supporting documents.
4.21 As for the provisions for the application of the steel materials for the main pressure parts, the steel materials that have been included in this document but not in the national standards for special steel plates for pressure vessels (pressure equipment), professional standards for special forgings, professional standards for special clad steel plates, and national standards or professional standards for steel pipes (except for steel materials as specified in 4.3), as well as the foreign grades of steel materials, their technical requirements shall be as specified in Annex A.
4.22 The pressure vessel manufacturers or the on-site welding organization shall obtain written approval from the original design organization for the substitution of the steel materials for pressure parts, and make detailed records on the as built drawings.
4.23 The to-be-met technical requirements for steel materials to be incorporated into this document are as specified in Annex B.
4.24 The allowable stress of each steel material shall be determined according to TSG 21 and GB/T 150.1, and the allowable stress of each steel material shall be determined as specified in Tables C.1 to Table C.8. The allowable stress at the middle temperature of each steel material in the allowable stress table may be obtained by interpolation method.
4.25 The application provisions of Q235 series steel plates shall be as specified in Annex D.
4.26 As for the steel materials, the high-temperature yield strength, and the average high-temperature endurance strength limit are shown in Tables E.1 to E.8, and Tables E.9 to E.12 respectively, while the elastic modulus and the average linear expansion coefficient are shown in Tables E.13 and E.14 respectively.
4.27 The approximate comparison of high-alloy steel grades is shown in Table F.1.
5 Steel plate
5.1 Non-alloy steel plates and alloy steel plates
5.1.1 As for the service status, thickness, upper service temperature limit and allowable stress of the steel plates in GB/T 713.1, GB/T 713.2, GB/T 713.3, GB/T 713.4 and GB/T 713.6, the relevant provisions in Table C.1 shall prevail.
5.1.2 All steel plates rolled from continuous casting billets or steel ingots in Table C1 shall have a compression ratio not less than 3.0, and steel plates rolled from directionally solidified steel billets shall have a compression ratio not less than 2.4. The steel plates rolled by electroslag remelting billet shall have a compression ratio not less than 2.0.
5.1.3 The steel plates delivered by the steel plate manufacturers shall be supplied in the service state as shown in Table C.1.
5.1.4 The following non-alloy and low-alloy steel plates shall be put into application under as-normalized condition.
a) Q245R, GB/SA516 Gr 485 and Q345R ones for cylinders of multilayer vessels;
b) Q245R, GB/SA516 Gr 485 and Q345R ones with thickness greater than 36 mm for housing;
c) Q245R, GB/SA516 Gr485 and Q345R ones with a thickness greater than 60 mm for other pressure parts (flanges, tube plates, flat covers, etc.)
d) Q345R ones with a thickness greater than 50 mm, the as-normalized and tempered condition of which may replace the as-normalized condition.
5.1.5 The following non-alloy steel plates and alloy steel plates shall be subjected to tensile and V-notch impact tests plate by plate (plate for heat treatment) (the impact test temperature shall be as specified in the corresponding steel plate standards):
a) quenched-tempered heat treatment steel plates;
b) cylinder steel plates of multilayer vessels;
c) steel plates with a housing thickness greater than 60 mm.
5.1.6 For steel plates for housings with a thickness greater than 36 mm under quenched-tempered condition and with a thickness greater than 80 mm under as-normalized condition or as-normalized and tempered condition, a set of impact tests on the specimens taken at 1/2 of the thickness may be added. The impact test temperature shall comply with the corresponding steel plate standards, and the impact performance indicators shall be as specified in Table 1. If the impact performance indicators of the specimens taken at 1/2 of positions in GB/T 713.1, GB/T 713.2, GB/T 713.3, GB/T 713.4, and GB/T 713.6 are higher than those specified in Table 1, they shall also comply with the corresponding steel material standards.
Contents of GB/T 150.2-2024
Foreword I
Introduction III
1 Scope
3 Terms and definitions
4 General requirements
5 Steel plate
6 Steel tube
7 Steel forgings
8 Steel bars for studs (including bolts) and nuts
9 Welding materials
Annex A (Normative) Supplementary requirements for steel
Annex B (Normative) Technical requirements shall be met for steels included in this document
Annex C (Normative) Allowable stress of steels
Annex D (Normative) Provisions on the use of Q235 series steel plates
Annex E (Informative) High-temperature yield strength, average of high-temperature endurance strength limit, elastic modulus and average coefficient of linear expansion of steels
Annex F (Informative) Approximate comparison of high alloy steel designations
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