GB/T 19624-2004 Safety assessment of in-use pressure vessels with defects
Some standard content:
ICS23.020.3013.110
National Standard of the People's Republic of China
GB/T19624—2004
Safety assessment for in-service pressure vessels containing defects
defects2004-12-29 Issued
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
2005-06-01 Implementation
GB/T19624—2004
1 Scope
2 Normative references
3 Terms, definitions and symbols
5 Fracture and plastic failure assessment
6 Fatigue failure assessment
Appendix A (Normative Appendix)
Appendix B (Normative Appendix)
Appendix C (Normative Appendix)
Appendix D (Normative Appendix)
Appendix E (Informative Appendix)
Appendix F (Informative Appendix) Appendix G (Normative Appendix)
Appendix H (Normative Appendix)
Interference effect coefficient between defects
Methods for determination and selection of material performance data Load ratio L, Calculation of parameters
Calculation of stress intensity factor K,
Effect of stress corrosion and high temperature creep environment on safety assessment Analysis and assessment method of plane defects.·
Safety assessment method of plane defects in straight sections of pressure pipelines Safety assessment method of volume defects in straight sections of pressure pipelines 29
GB/T19624-—2004
Appendix A, Appendix B, Appendix C, Appendix D, Appendix G, and Appendix H of this standard are normative appendices, and Appendix E and Appendix F are informative appendices.
This standard is proposed by China Special Equipment Testing and Research Center. This standard is under the jurisdiction of the National Technical Committee for Standardization of Boilers and Pressure Vessels. The responsible drafting units and main drafting personnel of this standard are: China Special Equipment Testing and Research Center: Chen Gang, Li Xueren, Zuo Shangzhi, Sun Liang, Tao Xuerong, Jia Guodong; Beijing University of Aeronautics and Astronautics: Zhong Qunpeng, Tian Yongjiang; East China University of Science and Technology: Li Peining, Wang Zhiwen; Tsinghua University: Yu Shouwen, Dong Yamin; Hefei General Machinery Research Institute: Chen Xuedong, Zhang Liquan, He Heren, Wang Bing; Sinopec Economic and Technological Research Institute: Shou Binan; Zhejiang University of Technology: Zhang Kangda; Dalian University of Technology: Qin Hong; China General Petrochemical Machinery Engineering Company: Xiao Yougu; Zhejiang University: Wang Kuanfu; Nanjing University of Technology: Shen Shiming.
GB/T19624—2004
This standard is a method for safety assessment of in-use defective pressure vessels and pressure pipelines proposed to meet the requirements of relevant national laws and regulations on safety assessment of in-use defective pressure vessels and pressure pipelines and engineering needs. This standard is based on the principles of "fitness for use" and "weakest link" and is used to determine whether in-use defective pressure vessels can continue to be used safely under the specified operating conditions. The pressure-bearing components of boilers and pipelines can also be safety assessed with reference to this standard. It is a safety assessment method suitable for actual engineering.
1 Scope
Safety assessment of in-use defective pressure vessels
GB/T19624—2004wwW.bzxz.Net
This standard specifies the terms, definitions and symbols, general discussion, fracture and plastic failure assessment, and fatigue failure assessment for safety assessment of in-use defective pressure vessels.
This standard applies to the safety assessment of in-use steel pressure vessels with excessive defects. Pressure-bearing components in boilers, pipelines and other metal containers can also be used as a reference when conducting safety assessments. This standard applies to the safety assessment of pressure-bearing components containing the following types of defects: Plane defects: including cracks, lack of fusion, lack of penetration, undercuts with a depth greater than or equal to 1mm, etc.; Volume defects: including pits, pores, slag inclusions, undercuts with a depth less than 1mm, etc. This standard does not apply to the following pressure vessels and structures: pressure vessels and structures that are subject to nuclear radiation in nuclear power plants; non-independent pressure-bearing components on machines (such as compressors, generators, pumps, pressure shells or cylinders of diesel engines, etc.); pressure-bearing components that are subject to direct fire;
- Capacitor pressure vessels (enclosed electrical appliances) for enclosed electrical equipment dedicated to the power industry: pressure vessels and structures with potential failure modes of coiling. 2 Normative reference documents
The provisions in the following documents become the provisions of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties that reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version is applicable to this standard. GB150—1998 Steel Pressure Vessels
GB/T-228—2002
GB/T229—1994
GB/T232—1999
GB/T699—1999
GB/T1172—1999
GB/T20381991
GB/T 2358-1994
GB/T2970—1991
GB/T3077--1999
GB/T3280—1992
GB3531—1996
GB 4161--1984
Metallic materials room temperature tensile test method (eqvISO6892:1998)Metallic Charpy notch impact test method (eqyISO148:1983)Metallic materials bending test method (eqvISO7438:1985)High-quality carbon structural steel
Conversion value of hardness and strength of ferrous metals
Metallic materials ductile fracture toughness Jic test methodMethod for crack tip opening displacement of metallic materialsUltrasonic test method for medium and thick steel plates
Alloy structural steel (negD INEN10083-1:1991) Cold-rolled stainless steel plate
Low-alloy steel thick plate for low-temperature pressure vessels Metallic material plane strain fracture toughness Kc test method GB/T42371992
Hot-rolled stainless steel plate (neqJISG4304:1984) 3 Fatigue crack growth rate test method for metallic materials (eqyASTME647:1995) GB6398—1986
GB6654—1996
Carbon steel and low-alloy steel thick plate for pressure vessels G B12337-—1998
Steel spherical storage tank
GB/T15970.6—1998Corrosion of metals and alloys-Stress corrosion testing-Part 6: Preparation and application of pre-crack specimensJB4708—2000
Welding procedure assessment for steel pressure vessels
GB/T19624—2004
Steel tower container
JB4710
JB4726-2000Carbon steel and low alloy steel forgings for pressure vesselsJB4727—200 0
JB4728—2000
Carbon steel and low alloy steel castings for low temperature pressure vesselsStainless steel forgings for pressure vessels
JB4730-1994Nondestructive testing of pressure vessels
JB4732-1995Analysis and design standard for steel pressure vessels3Terms, definitions and symbols
3.1Terms, definitions
Defects exceeding standard refers to defects exceeding the allowable size specified in the relevant pressure vessel manufacturing or acceptance standards and laws and regulations. 3.1.2
Fracture assessment
The safety assessment of defective pressure vessels and structures is to be conducted by using the fracture mechanics method to evaluate whether fracture failure can be excluded. 3.1.3
plasticcollapseassessment
Plastic failure assessment
Use the plastic limit analysis method to evaluate whether the pressure vessels and structures with defects can exclude plastic failure. 3.1.4
fatigue assessment
Evaluate whether the pressure vessels and structures with defects can exclude fatigue failure under the expected fatigue load within the required continued service period.
Defect characterizationdefectcharacterizationSimplifying the actual defect into a defect of a simple geometric shape according to the rules is called defect characterization or defect regularization. The defect size that has been characterized or regularized is called the characterized defect size. 3.1.6
Equivalent crack size effectivecracksize, Equivalentcracksize In the simplified assessment of plane defects, according to the principle of equal stress intensity factor, the characterized elliptical buried crack or semi-elliptical surface crack is replaced by a through crack with equal stress intensity factor. The half length of the through crack is called the equivalent crack size. 3.1.7
Plastic limit load plasticcollapseload The maximum load that the structure can withstand is calculated by the limit analysis method, based on the assumption of ideal plastic material and the average value of the actual material yield strength and tensile strength as the material's flow stress. 3.1.8
Plastic yield load plasticyieldload The maximum load that the structure can withstand is calculated by the limit analysis method, based on the assumption of ideal plastic material and the actual material yield strength.
Bulging effectbulgingeffect
The force of internal pressure on the shell surface forces the shell to bulge locally at the defective part, resulting in the actual stress intensity factor value at the crack tip being higher than the stress intensity factor value calculated without considering the local bulge. This phenomenon is called the bulging effect. The magnification of the increase in the stress intensity factor caused by the bulging effect is called the bulging effect coefficient Mg. 2
ROR materialRORmaterial
Material whose stress-strain relationship satisfies e/e,一a/a,十a(a/a,)\. 3.2 Symbols (excluding the special symbols in Appendix FG and H) The symbols used in this standard have the following meanings:
GB/T19624—2004
The coefficient in the relationship between the fatigue crack growth rate of the material and △K, N-\·mml1+3m/2)cycle-1; Charpy V-notch impact energy,;
The regularized characterization crack size of a planar defect (a through crack is half its length; a two-dimensional defect is half the length of the minor axis after ellipticalization, that is, the depth of a surface crack, half the height of a buried crack, or a corner crack Depth of cracks along the nozzle wall), mm;
a value of the larger of two adjacent coplanar cracks, mm; a value of the smaller of two adjacent coplanar cracks, mm; final size of crack after fatigue extension, mm; a value after the i-th fatigue (stress) cycle, i-1, 23, .... n, mm; average value of crack size a in the i-th calculation segment in the fatigue extension segment calculation method, j=1,2,3, ...u, mm,
a value of initial crack in fatigue analysis, mm;
equivalent crack size of defects in simplified assessment, mm; Maximum allowable equivalent crack size of defects in simplified assessment, mm; Calculated shell thickness for assessment, i.e., the shell thickness of the container near the defect after deducting the amount of inner and outer wall corrosion in one assessment cycle (B=BC), mm;
When calculating the secondary bending stress caused by misalignment in butt welded joints, the larger value of the container wall thickness on both sides of the misalignment, mm;
When calculating the secondary bending stress caused by misalignment in butt welded joints, the smaller value of the container wall thickness on both sides of the misalignment, mm;
Distance from the inner corner to the outer corner of the pipe, mm ; Calculated thickness of the pipe used for assessment, i.e. the pipe wall thickness near the defect after deducting the amount of inner and outer wall corrosion in one assessment cycle, mm;
Actual measured pipe wall thickness near the defect, mm;
Actual measured container shell wall thickness near the defect, mm; In the formula for calculating the secondary bending stress caused by misalignment in butt welded joints, the exponential term of the container wall thickness parameter, dimensionless:
Wall thickness reduction caused by inner and outer wall medium corrosion within
assessment cycles, mm; Characterizes the half length of an elliptical buried crack or a semi-elliptical surface crack along the shell surface, mm ; The c value of the larger of two adjacent coplanar cracks, mm; The c value of the smaller of two adjacent coplanar cracks, mm The final size of the crack after fatigue extension, mm The c value after the ith fatigue (stress) cycle, mm The average value of the crack size c in the calculation segment in the fatigue extension segment calculation method, j1,2,3, The c value of the initial crack in fatigue analysis, mm;
Average diameter of container, mm;
Inner diameter of container, mm;
Inner diameter of pipe, mm
GB/T19624—2004||tt| |Jr(Aa)
Average diameter of the nozzle, mm;
Outer diameter of the container, mm;
Outer diameter of the nozzle, mm;
Number of stress variation ranges of different sizes in fatigue assessment, dimensionless; When calculating the secondary bending stress caused by angular deformation in a butt welded joint, half of the projection length of the straight edge of the angular deformation in the wall thickness direction on the section perpendicular to the weld, mm; Working time at a specified temperature and specified stress, h; Stress corrosion crack growth rate, mm/s; Material elastic modulus, MPa; Characterizes the eccentricity of the buried elliptical crack center from the center of the wall thickness, mm; Misalignment, mm;
Boundary correction factor for the crack at the nozzle corner, dimensionless; General term for fh and fm, dimensionless;
General term for f6 and, dimensionless;
Crack configuration factor used in calculating the stress intensity factor at the crack tip in the α direction of the crack size caused by bending stress, dimensionless;
Crack configuration factor used in calculating the stress intensity factor at the crack tip in the α direction of the crack size caused by bending stress Zi, dimensionless;
The factor used in calculating K of corner cracks, dimensionless; The general term for fa and, dimensionless;
The crack configuration factor used in calculating the stress intensity factor at the crack tip in the α direction of the crack size caused by the film stress, dimensionless;
The crack configuration factor used in calculating the stress intensity factor at the crack tip in the c direction of the crack size caused by the film stress, dimensionless;
The elastic-plastic interference effect coefficient between two adjacent cracks, dimensionless; The parameter that comprehensively describes the size of the pit defect, dimensionless, G. The allowable limit value, dimensionless;
The measured maximum self-height of the defect along the plate thickness direction, mm; The size of the fillet weld leg, mm;
The respective codes of the d types of stress variation ranges, i-1,2,3,..,d, dimensionless; J integral value, N/mm;
The material integral fracture toughness corresponding to the brittle fracture point or breakthrough point when the material stable crack extension Aa<0.2mm, that is, the brittle fracture or breakthrough occurs, N/mm;
When the material stable crack extension Aa>0.2mm, the material J integral fracture toughness corresponding to Aa=0.2mm, N/mm;
The material integral fracture toughness measured by the metallographic section method, N/mm; The J resistance curve of the material, N/mm;
The number of segments for calculating the crack extension into u segments, j1,2,3,..…, u, dimensionless; fracture toughness of materials expressed in stress intensity factor, or fracture toughness of materials expressed in stress intensity factor converted from J-integral fracture toughness/CTOD fracture toughness, N/mm3/2I-type stress intensity factor, N/mm32;
plane strain fracture toughness of materials, N/mm3/2; Kiscc
GB/T19624—2004
limit stress intensity of stress corrosion cracking of materials in corresponding medium environment, N/mm32; fracture toughness of materials expressed in stress intensity factor after considering partial safety factor in conventional assessment of plane defects Toughness, N/mm3/2;
Fracture ratio for conventional evaluation of plane defects, refers to the ratio of the stress intensity factor under the applied load to the fracture toughness of the material expressed by the stress intensity factor, dimensionless: stress concentration factor, dimensionless:
Stress intensity factor caused by primary stress, N/mm/2, stress intensity factor caused by secondary stress, N/mm3/2; minimum spacing between two pits, mm;
Half the length of the plate, mm;
Load ratio, refers to the ratio of the applied load that causes primary stress to the plastic yield limit load, indicating that the load is close to the plastic yield limit load of the material. degree of load, dimensionless; the distance between two adjacent symmetrical weld toes on a weld joint with a weld toe crack or a fillet weld root crack, mmL, the allowable limit, dimensionless;
the maximum measured length of a plane defect along the free surface of the shell, tmm; when calculating the bending secondary stress caused by angular deformation in a butt weld joint, the total span of the two straight-side segments of the angular deformation on the section perpendicular to the weld, mm;
the linear elastic interference effect coefficient between two adjacent cracks, dimensionless; the swelling effect coefficient, dimensionless;
the exponent in the relationship between the fatigue crack growth rate and △K, dimensionless the total number of constant amplitude fatigue stress cycles number, cycle; exponential term in the stress-strain relationship of ROR material, dimensionless; number of cycles representing the stress variation range of (Ao) and (Aog), cycle; primary stress, MPa;
primary bending stress, MPa;
structural plastic limit load obtained by limit analysis based on the material rheological stress value, MPa; primary membrane stress, MPa;
structural plastic yield load obtained by limit analysis based on the material yield strength value, MPa; container working pressure required by safety assessment, MPa; distance between the hidden defect and the two surfaces of the shell plate, and pi
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