Detail of GB/T 4732.2-2024

Introduction of GB/T 4732.2-2024

GB/T 4732.2-2024 Pressure vessels design by analysis - Part 2: Materials 1 Scope This document specifies the allowable designations and standards of steel for pressure components of steel pressure vessels designed using design-by-analysis approach, the additional technical requirements for steel, the scope of use of steel (temperature and pressure), the allowable stress of steel, and the basic requirements for welding materials. This document is applicable to pressure vessels at design temperature of -269℃~800℃ and design pressure less than 100MPa. This document is not applicable to the scope of inapplicability specified in GB/T 4732.1. 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 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 713.2 Steel plate, sheet and strip for pressure equipments - Part 2: Non-alloy and alloy steel with specified temperature properties GB/T 713.3 Steel plate, sheet and strip for pressure equipments - Part 3: Low alloy steel with specified low temperature properties GB/T 713.4 Steel plate, sheet and strip for pressure equipments - Part 4: Nickel-alloy steels with specified low temperature properties GB/T 713.5 Steel plate, sheet and strip for pressure equipments - Part 5: High manganese steel with specified low temperature properties GB/T 713.6 Steel plate, sheet and strip for pressure equipments - Part 6: Quenched and tempered high strength steel 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 4732.1 Pressure vessels design by analysis - Part 1: General requirements 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 34542.2 Storage and transportation systems for gaseous hydrogen - Part 2: Test methods for evaluating metallic material compatibility in hydrogen atmosphere 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 47008 Carbon and alloy steel forgings for pressure equipment NB/T 47009 Alloy steel forgings for low temperature pressure equipment NB/T 47010 Stainless and heat-resisting steel forgings for pressure equipment 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 equipments 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 Specification 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 4732.1 apply. 4 General requirements 4.1 The steel and welding materials for steel plates, tubes, forgings and studs (including bolts) for pressure components of pressure vessels shall comply with TSG 21. 4.2 The steel used for the pressure components of pressure vessels shall be of good weldability. 4.3 The austenitic stainless steel not listed in this document but listed in GB/T 20878 and GB/T 713.7 can be adopted, but their phosphorus, sulfur content and strength indicators shall not be inferior to those specified in the corresponding steel standards listed in this document for designations of steel with similar chemical composition. 4.4 Except for the steel that meets the requirements of 4.3, the technical requirements for other steels not listed in this document shall comply with the provisions of Annex A. 4.5 The steel for pressure components of pressure vessels shall be accompanied by the steel quality certificate of the steel manufacturer. The quality certificate shall have complete and clear contents, printed with traceable information identification, and stamped with the quality inspection seal of the material manufacturer. Traceable information includes the name of the steel manufacturer, steel standard No., designation, specification, furnace batch No., delivery status, heat treatment process parameters (when necessary), issuance date of quality certificate, etc. Traceable information identification shall be two-dimensional codes or barcodes. 4.6 The vessel manufacturer shall perform acceptance inspection on the steel according to the quality certificate. If there is no original steel quality certificate of the steel manufacturer, the official seal of the material operation organization and the signature (seal) of the person in charge of the handling shall be affixed to the copy of the original steel quality certificate. 4.7 The selection of steel for pressure components of pressure vessels shall be based on the service conditions (e.g., design temperature, design pressure, medium characteristics and operating characteristics, etc.), the chemical composition, microstructure, properties (mechanical properties, process properties, chemical properties and physical properties) of the steel, as well as the manufacturing process and economic rationality of the vessel. 4.8 The steel for pressure components of pressure vessels shall be smelted in oxygen converter or electric furnace, or by electroslag remelting process. Low-alloy steel plates and forgings, austenitic-ferritic stainless steel plates with the lower limit of standard tensile strength greater than 540MPa, and low-temperature steel plates, forgings and tubes with the service temperature below -20℃ shall also be refined outside the furnace and vacuum treated. 4.9 The upper limit of service temperature of steel for pressure components of pressure vessels shall comply with the following requirements. a) The upper limit of service temperature of steel is the maximum temperature corresponding to the allowable stress of each designation of steel in Tables B.1 to B.8 in Annex B and the allowable stress on the right side of the thick line in Tables B.1 to B.8 is determined by the average value of the 105h high-temperature durable strength limit of the steel. If the steel needs be operated above the upper limit of service temperature for a short time due to technological requirements, it shall be specified in the design documents. b) As for the non-alloy steel and carbon manganese steel, when they are used at a temperature higher than 425℃ for a long time, attention shall be paid to the graphitization tendency of the carbide in the steel. c) When the service temperature of austenitic stainless steel is higher than 525℃, the carbon content in the steel shall not be less than 0.04%. 4.10 The lower limit of service temperature of steel for pressure components of pressure vessels shall comply with the following requirements. a) The lower limit of service temperature of steel shall meet the requirements of Clauses 5 to 8. b) The lower limit of service temperature of austenitic stainless steel is -269℃. When the service temperature is higher than or equal to -196℃, the impact test may be exempted. If the service temperature is lower than -196℃, the low-temperature impact test at the design temperature of pressure vessels shall be carried out. The average impact absorption energy () of three standard specimens is not less than 54J and the average lateral expansion () is not less than 0.53mm. Austenitic-ferritic stainless steel may be subjected to the impact test with the lowest impact test temperature of -40℃. The average impact absorption energy () of three standard specimens is not less than 47J and the average lateral expansion () is not less than 0.53mm. Other requirements for impact test shall be as specified in 4.11b) and 4.11c). c) The austenitic stainless steel for liquid hydrogen pressure vessels shall undergo impact test at -253℃, and the austenitic stainless steel for liquid helium pressure vessels shall undergo impact test at -269℃. The impact properties shall be as specified in 4.10b). 4.11 The impact test of non-alloy and alloy steel shall meet the following requirements. a) The impact properties of non-alloy and alloy steel (steel plates, tubes and forgings) shall meet the requirements of Table 1. Note 1: When the lower limit of standard tensile strength of steel 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 steel at the minimum thickness.

Contents of GB/T 4732.2-2024

Contents 1 Scope 2 Normative references 3 Terms and definitions 4 General requirements 5 Steel plates 6 Steel tubes 7 Steel forgings 8 Steel bars for studs (including bolts) and nuts 9 Welding materials Annex A (Normative) Supplementary provisions for steel Annex B (Normative) Allowable stress of steel Annex C (Informative) High-temperature yield strength, average of high-temperature endurance strength limit, elastic modulus and average linear expansion coefficient of steel Annex D (Informative) Approximate comparison table of high alloy steel designations Bibliography