JB/T 1266-2002 Technical requirements for 25MW~200MW steam turbine wheel and impeller forgings
Some standard content:
ICS77.140.85
Machinery Industry Standard of the People's Republic of China
JB/T1266-1993
Specification for disk and wheel forgings for 25MW to 200MW steam turbines
Published on 2002-12-27
Implemented on 2003-04-01
Published by the State Economic and Trade Commission of the People's Republic of China Foreword||tt| |2 Normative reference documents
Ordering requirements.
4 Technical requirements..
Manufacturing process.
Chemical composition
Mechanical properties
Hardness uniformity
Residual stress
Grain size..
Non-destructive testing
Testing rules and test methods
Chemical composition analysis
Mechanical properties test,
Hardness uniformity test
Residual stress test
Grain size test
Non-destructive testing
Reheat treatment
Acceptance and certificate of conformity
Marking and packaging.
Table! Mass fraction of chemical composition.
Table 2 Permissible deviation of mass fraction of chemical compositionTable 3 Mechanical properties,
JB/T1266—2002
This standard replaces JB/T1266--1993. "Technical Conditions for 25~200MW Steam Turbine Disc and Impeller Forgings". Compared with JB/T1266-1993, the main changes of this standard are as follows: JB/T1266-2002
In accordance with GB/T1.1--2000 "Guidelines for Standardization Work Part 1: Structure and Writing Rules of Standards" and related standards, the original standard has been edited and revised:
In Table 3 of 4.3 of the original standard, the upper and lower limits of the 00.2 index of the three strength levels of 690, 730 and 760 are specified, and the lower limit of the 0 index is specified: Some 6+, AkY, and FATTs indicators have been revised: - The FATTso of 25CrNiMoV and 34CrNi3Mo forgings in Table 3 of 4.3 of the original standard has been changed from a reference index to an acceptance index, and the FATTso test method of impeller forgings has been clarified:
- The pickling test and related contents have been cancelled:
- The sampling position boundary of 5.2.2 of the original standard has been slightly modified. This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of Deyang Large Casting and Forging Research Institute. The drafting units of this standard are China Second Heavy Machinery Group Corporation and Dongfang Steam Turbine Factory. The main drafters of this standard are Liu Gaoxian and Zhong Jie. This standard was first issued in 1972, revised for the first time in 1985, and revised for the second time in 1993. 1. Scope
JB/T1266-2002
Technical conditions for 25MW~200MW steam turbine wheel discs and impeller forgings This standard specifies the technical requirements, inspection rules, test methods, certificates and marks for vacuum-treated alloy steel parts for 25MW~200MW steam turbine rotor wheel discs and impellers. This standard is applicable to the ordering, manufacturing and inspection of vacuum-treated alloy steel forgings for 25MW~200MW steam turbine rotor wheel discs and impellers. 2. Normative references
The clauses in the following documents become the clauses 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. GB/T223.3~78 Chemical analysis methods for steel and alloys GB/T228 Metal tensile testing method
GB/T229 Metal Charpy notch impact testing method (GB/T229~-1994, eqvISO148:1983) GB/T231 Metal Brinell hardness testing method
JB/T1582-1996 Ultrasonic flaw detection method for turbine impeller forgings JB/T8468—1996 Magnetic particle inspection method for forged steel parts YB/T5148 Metal average grain size determination method ASTMA370
Test methods and definitions for mechanical properties of steel products 3 Ordering requirements
3.1 The purchaser shall specify the adopted standards, steel grades, forging strength grades, corresponding technical requirements, inspection items and inspection items other than the requirements of this standard in the ordering contract or technical agreement. The strength grade and steel number of forgings shall be marked on the drawings as follows: Steel number
Strength grade of forgings×Number of this standard
3.2 The purchaser shall provide the forging order drawing indicating the root diameter of the wheel flange groove and the sampling position for the mechanical properties test. 3.3 The inner hole finishing dimensions shall be provided if there are special requirements within the range of the inner hole diameter plus 60mm. 4 Technical requirements
4.1 Manufacturing process
4.1.1 Refining and pouring
4.1.1.1 Steel for forgings shall be smelted in an alkaline arc furnace. With the consent of the purchaser, other methods of smelting to ensure quality may also be used. 4.1.1.2 Before or during pouring, the molten steel shall be vacuum treated to remove harmful gases, especially hydrogen. 4.1.2 Forging
4.12.1 The upper and lower parts of the steel ingot shall be sufficiently removed to ensure that the finished forgings are free of shrinkage cavities, porosity, severe segregation and other harmful defects.
The forging method used must make the entire forging obtain a uniform structure as much as possible, and the forging press should have sufficient tonnage to forge the entire cut surface of the forging. 4.1.2.2
The axial height of the forged part should be at least twice the thickness of the forging before the forging is roughened. 4.1.3 Heat treatment
4.1.3.1 The heat treatment after forging is normalizing and tempering. 1
JB/T1266—2002
4.1.3.2 After rough machining, the forging is subjected to a heat treatment of rate quenching and tempering. The cooling rate of tempering should not be greater than 25℃/h4.1.4 Machining
Before the performance heat treatment, all surfaces of the forging should be rough machined. 4.1.4.1
4.1.4.2 The dimensional accuracy and surface roughness of the forging should comply with the requirements of the order drawing. 4.1.5 Welding
Welding is not allowed for forgings during manufacturing and packaging and transportation. 4.2 Chemical composition
4.2.1 The mass fraction of the chemical composition of the smelting analysis shall comply with the provisions of Table 1. 4.2.2
The mass fraction of the chemical composition of the finished forging shall comply with the provisions of Table 1, but the deviation specified in Table 2 is allowed. Table 1 Mass fraction of chemical composition
34CrMo1A
24CrMoV
35CrMoV
34CrNi3Mo
25CrNiMoV
30Cr2Nj4MoV
0.20~0.28
0.30~0.40
0.30 0.40
0.40~0.70
0.30~0.50
0.40~0.70
0.50-0.80
0.20~0.40
0.17~0.37
0.17~0.37
0.17-0.37
0.17~0.37
≤.0.020
Note: When vacuum carbon deoxidation is used, the silicon content should not exceed 0.10%. Table 2
Chemical composition
Allowable deviation
Mechanical properties
0.70~1.20
1.00 ~ t.30
0.70~1.10
1.00~ 1.50
1.50~2.00
2.75~3.25
1.00~1.50
3.25~3.75
Permissible deviation of mass fraction of chemical compositionSi
The mechanical properties of forgings at temperature should conform to the requirements of Table 3S
Table 3 Mechanical properties
8,(6,)
Agu (Agv)
FA7TsC
Recommended steel
≥440
≥640
24CrMoV
35CrMoV
≥540
34CrMo1A
35CrMoV
25CrNiMo V
≥640
25CrNiMoV
0.40~0.55
0.50~0.60
0.25~0.40
0.25~0.45
0.30 ~0.60
Ni composition upper limit
690~ 820
34CrNi3Mo
730~860
(6.≥17)
≥35(≥45)
(Axv≥61)||tt ||≤20(≤30)
34CrNi3Mo
(30Cr2Ni4MoV)
Note: 30Cr2Ni4MoV, 34CrNi3Mo, 25Cr FATTso of NiMoV forgings is the guaranteed value, and the rest are reference values, 2
0.10~0.20
0.07~0.15
0.07~0.15
760890
Av ≥61
30Cr2Ni4MoV
4.4 Hardness uniformity
JB/T1266-2002
Silver parts should be checked for hardness uniformity after heat treatment. The absolute value of hardness is provided. The uniformity requirement of hardness is as follows: measure one point every 90° in the radial direction of the rim and hub (eight points in total), and the hardness difference between any two points between the rim and hub should not exceed 40HBS. The hardness difference between each point on the rim and each point on the hub shall not exceed 30HBS. 4.5 Residual stress
When the diameter of the forging is greater than 600mm, the residual stress shall be checked after the final heat treatment. When the diameter of the forging is 600mm~1000mm, the residual stress shall not be greater than 40MPa; when the diameter of the forging is greater than 1000mm, the residual stress shall not be greater than 50MPa. 4.6 Grain size
The average grain size of forgings shall not be coarser than Grade 4.0. The specimens shall be taken from the mechanical properties test bars. 4.7 Nondestructive testing
4.7.1 General requirements||tt| |Forgings should not have cracks, white spots, shrinkage holes, folds, excessive segregation, and inclusions and looseness exceeding the allowable limit. 4.7.2 Magnetic Particle Inspection
The purchaser shall conduct magnetic particle inspection on the shaft hole and hub end face (all surfaces if necessary) of the forging after processing. The supplier shall ensure that the inspection results meet the following requirements:bZxz.net
a) The number of single defects with a length of 1.0mm to 2.0mm shall not exceed 12; b) The number of single defects with a length greater than 2.0mm to 3.5mm shall not exceed five; c) No defect with a length greater than 3.5mm shall be allowed; d) On the same busbar, when the distance between two defect indications is less than five times the length of the larger defect indication, the connecting line of the two defect indications shall be regarded as one defect indication. Local grinding and polishing can be carried out in areas where grinding is allowed, but the grinding depth must not exceed 1.5mm and must have a smooth transition with the surrounding surface.
4.7.3 Ultrasonic Inspection
After the forgings are heat treated, the supplier shall inspect the forgings and provide a report to the buyer: The buyer shall inspect the wheel rim and spokes after final processing. Ultrasonic testing should be carried out on all detectable surfaces. The acceptance criteria are as follows: a) Single scattered defects with an equivalent diameter of less than 2 mm are not counted, but the noise height should be less than 50% of the radius of the equivalent diameter of 2 mm; b) Definition of single scattered defects The distance between two adjacent defects is greater than 10 times the equivalent diameter of the larger defect. c) Within the 25mm deepening range of the wheel flange groove root, there shall not be a defect concentration area with an equivalent diameter greater than or equal to 1.6mm and an equivalent diameter greater than For defects of 2mm, other parts are allowed to have defect-dense areas with an equivalent diameter of 1.6mm to 2.0mm (excluding 2.0mm). The distance between each area shall not be less than 120mm, and the number of dense areas shall not exceed three. d) Other areas allow for the existence of single scattered defects with an equivalent diameter of 2mm to 4mm, but the number of defects should not exceed 10 in an area of 100cm2.
When the user requires, the equivalent diameter within the range of inner hole diameter plus 60mm Defects with a diameter greater than 2mm4mm are not allowed to be distributed on the same radius or beyond the dense defect area. 4.7.4 Handling of defects exceeding the regulations
Defects exceeding the above regulations shall be resolved through negotiation between the two parties. 5 Inspection Rules and test methods
5.1 Chemical composition analysis
5.1.1 Chemical composition analysis shall be carried out according to the methods specified in GB/T223.3~78 or other methods that can ensure the quality of analysis. If the smelting analysis sample does not meet the requirements, the finished product analysis can be used instead of the smelting analysis. When sampling from forgings, the chemical composition should meet the requirements of finished product analysis.
5.1.3 The finished product analysis sample can be taken from the forging mechanical properties test ring. Or taken from mechanical properties test specimens. 20% (but not less than two pieces) of forgings with the same drawing number and the same smelting furnace number are taken for inspection. 5.2 Mechanical properties inspection 5.2.1 Inspection period
Mechanical properties inspection is carried out after performance heat treatment. 5.2.2 Sampling location and quantity
When the inner hole diameter of the component is greater than or equal to 300mm, the inner wall of the inner hole should be cut. Samples: When the inner hole diameter is less than 300mm, the samples are cut from the wheel hub end or the outer circle of the wheel hub. Each set of samples includes one tensile sample, three room temperature impact samples and three FATT50 samples.
5.2.3 Tensile test
30Cr2Ni4MoV forgings use specimens with a diameter of 12.5mm and a gauge length of 50mm, as specified in ASTMA370; other steel forgings use specimens with a diameter of 10mm and a gauge length of 50mm, as specified in ASTMA370. 5.2.4 Room temperature impact test
30Cr2Ni4MoV forgings use Charpy V-notch specimens and are carried out in accordance with ASTMA370; other steel forgings use Charpy U-notch specimens and are carried out in accordance with GB /T229 provisions, 5.2.5FATTse test
According to ASTMA370, three Charpy V-notch impact tests are carried out at the temperature specified in Table 3, and the percentage of fibrous new openings and impact absorption energy are reported respectively: The average value of the fibrous fracture percentage of the three specimens should be greater than or equal to 50% (the fibrous fracture percentage of one of the specimens is allowed to be lower than 50%, but not lower than 40%). 5.3 Hardness uniformity test
Hardness uniformity test shall be carried out in accordance with the provisions of GB/T231. 5.4 Residual stress test
5.4.1 The ring cutting method or other methods agreed upon by the supplier and the buyer shall be used to determine the residual stress of the forging. Residual stress. 5.4.2 When the ring cutting method is adopted, the purchaser shall select one piece from a batch of forgings heat treated in the same furnace and conduct residual stress test on each forging. When cutting a 25mmx25mm mechanical property test ring, measure the average deformation of the ring before and after cutting. The residual stress is calculated by the quantitative method. The calculation formula is
0,=Ex S/D
Where:
o, one by one residual stress, the unit is MPa: ||tt| | E--elastic modulus of material, unit is MPa5--algebraic value of diameter increment, unit is mm: D--outer diameter of the ring before cutting, unit is mm5.4.3 If the residual stress exceeds the provisions of 4.5, the batch Forgings should be checked for residual stress or re-tempered piece by piece. The re-tempering temperature should be 20℃~50℃ lower than the final tempering temperature. Hardness and residual stress tests should be repeated after tempering. 5.5 Grain size test||tt| |Grain size inspection shall be carried out in accordance with the provisions of YB/T5148. 5.6 Nondestructive testing
5.6.1 Magnetic particle testing shall be carried out in accordance with the provisions of JB/T8468-1996. 5.6.2 Ultrasonic flaw detection shall be carried out in accordance with the provisions of JB/T1582-1996. 5.7 Retest
5.7.1 If the mechanical properties If the test result of a certain sample fails during the inspection, two samples can be taken from the adjacent parts of the forging to conduct retests. If the retest results of the two samples and the test results of the initial test and retest are the same, the If the average values meet the specified requirements, the test result can be judged as qualified.
5.7.2 If the mechanical properties test fails due to white spots and cracks, retesting is not allowed. 4
5.8 Reheat treatment|| tt||JB/T12662002
5.8.1 If the forging mechanical properties retest still fails, reheat treatment is allowed. After reheat treatment, the forging should be resampled for mechanical properties test.
5.8.2 The number of reheat treatments (excluding re-tempering) shall not exceed two times. 6 Acceptance and Certificate of Qualification
6.1 The supplier shall provide the necessary convenience to the purchaser's acceptance personnel so that The inspection work is carried out by the acceptance personnel of the purchaser. 6.2 The purchaser has the right to select certain acceptance test items for forgings. If it is found during the acceptance test or in subsequent processing or testing that the forgings do not meet the supplementary technical requirements stipulated in this standard and the order contract, the purchaser shall promptly notify the supplier and the two parties shall resolve the issue through consultation. 6.3 The supplier shall provide the purchaser with a certificate of conformity (one certificate for one item). The certificate of conformity shall include the following: a) Contract number:
b) Forging drawing number:
Standard number, forging strength grade and steel grade: c)
d) Melting furnace number, melting method and forging card number (or ingot section number): Chemical analysis results:
Actual temperature, holding time and cooling method of performance heat treatment: f)
Test results of mechanical properties:
Ultrasonic flaw detection report:
Results of other tests and additional tests required by the purchaser: i
Actual size and weight of the delivered forgings.
7 Marking and Packaging
7.1 The supplier shall mark the contract number, part number, smelting furnace number, forging card number (or ingot section number) and factory name on the outer peripheral surface of the wheel rim of each forging and circle it with white paint.
7.2 The supplier shall pack according to the transportation requirements.
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