JB/T 1270-2002 Technical requirements for main shaft forgings of turbines and hydro-generators
Some standard content:
ICS 77.140.85
Machinery Industry Standard of the People's Republic of China
JB/T 1270--2002
Replaces B/T127D1993
Specification for shaft forgings for hydroturbines and bydrogenerators2002-12-27 Issued
2003-04-01 Implementation
Issued by the State Economic and Trade Commission of the People's Republic of China Foreword
Normative reference documents
3 Order content
4 Technical requirements
Manufacturing process:
Chemical composition
Mechanical properties.
Non-standard inspection
Size, tolerance, surface roughness
5 Inspection rules and test methods,
5.1 Chemical composition analysis
5.2 Mechanical properties inspection
5.3 Residual stress test,
Non-standard inspection
5.5 Retest and new heat treatment
6 Acceptance and certificate
6.1 Acceptance
6.2 Certificate
6.3 Return policy
? Marking and packaging,
Table 1 Chemical base quality score
Table 2 Mechanical properties
Table 3 Finished product analysis exceeds the upper and lower allowable deviations
JB/T1270-2002
This standard replaces T1270-1993≤ Technical conditions for large forging of turbines and hydro-generators. Compared with JB/T1270-1993, the main changes of this standard are as follows: the open-hearth smelting in 4.1.1 of the original standard is adopted; JB/T1270-2002
revised 4.1.4 heat treatment in the original standard to 4.3.1, and clearly stipulated that the large shaft with mirror tax is not included in this requirement; the content of limiting the number of heat treatment changes in S.5.2 of the original standard is added; ..: the P and S content in the mass fraction of the chemical composition is increased from more than 0.030% to more than 0.025%;
the mechanical properties in the original standard are adjusted to 4.3.1! The overall indentation and structure of the standard are revised according to GB/T1.1-200 standardization work guide Part 1: Standardization structure and writing rules 3.
This standard was proposed by the China Machinery Industry Federation. This standard is approved by Deyang Large Equipment Research Institute. The drafting unit of this standard is China First Heavy Machinery Group Corporation. The main drafters of this standard are Zhang Guoli and Yuan Hongxing. This standard was first issued in 1972, revised for the first time in 1985, and revised for the second time in 1993.
1 Technical conditions for large shaft forgings of turbines and hydro-generators JB/I12702002
This standard specifies the technical requirements, inspection rules, or inspection methods, and certification marks for large shaft forgings (including welded shafts, hereinafter referred to as parts) of turbines and hydro-generators. This standard applies to the ordering, manufacturing and inspection of parts of turbines and hydro-generators. 2 Normative reference documents
The clauses in the following documents become the clauses of the standard through reference in this standard. For dated referenced documents, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties to the modification agreement under this standard are encouraged to study whether new versions of these documents can be used. For undated referenced documents, the latest edition shall apply. GB/T 223.3-78 Metal chemical analysis methods GB/T 228 Metal tensile test method GB/T 229 Metal notch impact test method (GB/T 229-1994, eg V1S0148:1983) GBT 11345 Grading of steel welds by ultrasonic testing JB/T 1581 Ultrasonic flaw detection method for rotors and main shafts of steam turbines and turbo-generators JB/T 8468 Magnetic particle inspection method for forged steel parts 3 Ordering instructions 3.1 The purchaser shall specify the part grade, number, standard number and required supplementary test items in the order contract or technical agreement. Forging grade and steel number are marked as follows on the sample: No.
Forging grade × This standard number
3.2 Full force should provide delivery drawings indicating the size of forgings with selected locations for mechanical property tests. 4 Technical requirements
4.1 Manufacturing process
4.1.1 Cold refining
Forging steel is smelted in a reductive electric furnace. With the consent of the purchaser, other smelting processes that ensure quality are allowed. 4.1.2 Head and tail cutting
The upper and lower ends of the forgings should be cut off sufficiently to ensure that the forgings have no shrinkage holes and no serious deflection. 4.1.3 Forging
On a forging press with sufficient capacity, the entire forging is fully forged, and the forgings are as close to the shape and size of the finished product as possible. The center line of the short piece and the pin should be aligned well. 4.1.4 Heat treatment
After forging, the supplier needs to carry out normalizing and tempering treatment to ensure that the parts have uniform structure and performance. 4.1.5 Welding
4.1.5.1 After the mechanical property test of a single forging is qualified, heat welding shall be carried out. Welding rods with the same mechanical properties as the forgings shall be used, and the best welding specifications shall be selected. Welding
JB/T12702002
4.1.52 If the welding force method adopts the electric During welding, normalizing and tempering are required after annealing. Mechanical properties and residual stress tests must be carried out again after tempering. If narrow gap automatic welding or other welding methods are used, high-temperature stress relief annealing is carried out after annealing. When the stress relief temperature is 30°C to 50°C lower than the tempering temperature, mechanical properties test does not need to be carried out again. If the tempering temperature is higher than the upper temperature, mechanical properties test needs to be carried out again. 4.2 Chemical composition The mass fraction of the chemical composition of the steel for parts shall comply with the provisions of Table 1. Table 1 Chemical composition by mass fraction
2USiMn
0.32·-0.400.J7-0.37
42·~0.50
.1 row~0.22
IBMnMoNb : .16i- 0.22
2aMnMts
0.17--0.23
4.3 Strength semi-performance
0.17--0.37
0.60--0.B0
0.20-0.40
0.17--0.37
0.50 -0.80
0.50--0.80
1.00--1.30
1.20--1.50
0.90~-1.30
≤:0.025
0.45~0.600.021)~0.045
0.15~0.25
4. White.1 After the forgings are treated by combustion at the supplier: the axial mechanical properties of the forgings shall comply with the provisions of Table 2 (the large shaft forgings with mirror plates shall be specified separately in the order contract).
Table 2 Mechanical properties
(%)
Flange
(%)
45A,20SiM, ZUMmM
IIMnMuNh
The integrity and impact energy of 25% of the total effective specimens are slightly lower than the values specified in the table, but cannot be lower than T: Fiber [: If the shaft can be sampled on the flange, the elasticity is 12%, the cross-sectional reduction is 20%; the impact average A is 20F Note 2: Sugar head refers to the flange that cannot be screwed.
4.3.2 When the flange screw cannot be screwed If the nail hole is not suitable for material preparation or the conditions for piercing are not met, the flange can be scratched or sampled. At this time, the tangential mechanical load should not be lower than the axial load of the flange part in Table 2. 4.3.3 The axial test specimen of the flange end can also be taken from its extended part (its diameter is equal to the first diameter of the shaft body). At this time, the mechanical properties are in accordance with the shaft head performance requirements in Table 2. 4.3.4 The welding mechanical properties of the welded large shaft shall not be lower than the polishing head performance in Table 2. 4.3.5 The residual stress (absolute value) of the general parts shall not exceed 39MPa. When there is no major change in the process, the residual stress test may not be performed. 4.4 Nondestructive testing
4.4.1 Surface of plated parts
Forging surfaces should not have visible marks, bone expansion and other appearance defects that affect use. Local depressions can be removed, but the depth of elimination shall not exceed 75% of the finishing allowance. For general defects exceeding the finishing allowance, repair welding is allowed. In case of serious defects, repair welding can be carried out with the consent of the purchaser. After repair welding, the following treatment and inspection should be carried out: After repairing, the supplier should carry out the following treatment:
Do ultrasonic damage and aldehyde washing (or powder avoidance) inspection. There should be no cracks. The hardness difference between the repair welding area and the base material shall not exceed 501.5: Provide inspection records
4.4.2 Center hole
The center hole of the forging shall be inspected by the supplier with a meat mask or a film, and the inspection results shall meet the following requirements: The center hole is not allowed to have large, loose, or shrinkage residues. b) Single and scattered defects: Single and scattered defects with a length not exceeding 8mm are allowed (when the distance between defects is not less than 10 times the length of the largest defect, it is called a single and scattered defect). 2
JB/T1270--2002
Defects of large area: On any 10m area: the number of defects with a length of 1.5mm--3mm shall not exceed 20. Point defects with empty chain distribution are not allowed. d:
When the defects exceed the standard, the two parties shall negotiate to make it happen
4.4.3 Magnetic powder or pickling control inspection
Forgings shall be inspected by magnetic powder or pickling, and no self-spot, crack or other defects are allowed. 4.4.4 Ultrasonic flaw detection
The outer surface of forgings shall be inspected by ultrasonic flaw detection, and the results shall meet the following requirements: No defects such as white spots, cysts, shrinkage, etc. are allowed. Defects with an equivalent diameter of less than 5mm are not allowed.
Dense defects with an equivalent diameter of 5mm and more than 5mm are not allowed. e
Single and discrete defects with an equivalent point diameter of mm--tOmm are allowed, but the distance between two adjacent defects shall not be less than five times the diameter of the larger defect.
Welded shaft coal chains should be subjected to ultrasonic probing tests, and the results should comply with the following provisions: 4.4.4.2
Cracks in any form and direction are not allowed. a)
Incomplete fusion and incomplete penetration are not allowed in any part. b:
When the single defect diameter is less than 5mm, it is not counted:
It is allowed to have a single defect and pore with a diameter not larger than 1mm, but the distance between two adjacent defects shall not be less than the diameter of the larger defect d
It is allowed to have a strip-shaped sink with a diameter not larger than 10mm, but the distance between two adjacent defects shall not be less than 50mm (a strip defect is a defect with a length-to-width ratio equal to or greater than 3). Within the weld of eight-stop thickness, the total length of continuous defects shall not exceed the weld wall thickness. 4.5 Dimensions, tolerances, surface roughness
4.5.1 The processing of forgings shall comply with the delivery drawings of the purchaser and the corresponding requirements of dimensions, tolerances and surface roughness. 4.5.2 The surface of the center hole of the forging shall be fine-bored by the supplier to a surface roughness R value of 3.2ul. 5 Inspection rules and test methods
5.1 Chemical composition analysis
5.1.1 Molten steel analysis
5.1.1.1 The supplier shall take samples of each heat of molten steel for analysis during the casting process and report the analysis results. When the steel is cast from multiple heats, the weighted analysis results shall comply with the requirements of Table 1. 5.1.1.2 If the test and sampling fail, or do not meet the analysis requirements, the supplier may take alternative samples at the appropriate position near the forging or the forging to determine the composition of the molten steel:
5.1.2 Finished product analysis
The supplier shall take samples for analysis at 1/2 of the thickness of the extended part of the general part (hollow forgings) or 1/3 of the radius of the surface (solid forgings) or on the mechanical test piece. The analysis results shall comply with the requirements of Table 2, and the deviations in Table 3 are allowed. Table 3 Permissible deviation of finished product analysis exceeding the upper and lower limits Element
Specified
Maximum range
0.26--0.55
Maximum diameter of finished silver piece
:>400--500
8G0~·1150
JE/T12702002
Specified amount
Range
0.41--1.15
5.1.3 Analysis method
Capsule 3 (Continued)
The most accurate and most reliable diameter of the product
400--500
5U0~800
-80J~1150
Analyze according to GDT223.3--7R, or use other methods that can ensure the same measurement accuracy. 5.2 Mechanical properties test
5.2.1 Sampling position and quantity
5.2.1.1 When the parts have flanges at both ends or both ends are without flanges, the supplier shall take samples at the inlet end of the parts and the buyer shall take samples at the sprue end; when the parts have flanges at one end, both the supplier and the buyer shall take samples at the flange end and the shaft head end. 5.2.1.2 For axial test, for sampling at the flange end, four tensile specimens and four impact specimens shall be taken at the flange screw inspection hole or at the position equivalent to this position; when sampling at the shaft head end, for parts with center shot, two tensile specimens and two impact specimens shall be taken at 1/2 of the total thickness, and for solid parts, two tensile specimens and two impact specimens shall be taken at 1/3 of the surface.
For tangential test, the residual stress ring of the flange or the corresponding position shall be cut, and two tensile specimens and two impact specimens shall be taken at the symmetrical position of the ring.
Welding mechanical properties of the main shaft welded by electroslag welding. Cut the specimens on the welding test plate of the main shaft forging, take two tensile test specimens and two impact test specimens: wwW.bzxz.Net
5.2.2 Test method and specimen size
5.2.2.1 The tensile test method is carried out according to GB/226. The specimen is a standard specimen with a diameter of 10mm and a gauge length of 50 μm. 5.2.2.2 The impact test method is carried out according to GB/229. The specimen is a Charpy E-type notched specimen with a size of 10mm×10mm×55mm and a notch depth of 2mm.
5.3 Residual stress test
5.3.1 After the final heat treatment of the forging, the residual stress is checked and the residual stress is measured by the ring cutting method or the ring core resistance strain method. 5.32 When the ring cutting method is used, when the flange diameter is less than 17 mm, if the two ends are flanged, the supplier should be in the appropriate! 1. The buyer shall cut the ring on the outer surface of the flange end of the water gate: if one end has a flange, the ring shall be cut on the outer surface of the flange end. When the flange diameter is greater than 1250mm, the ring shall be cut on the outer surface of the shaft head and the inner hole surface. The size of the remaining measuring ring is 2m2m. 5.3.3 The method of measuring the average deformation of the ring before and after cutting is used to calculate the stress. The calculation formula is: 4-ESD
Where:
o residual stress, unit is MPa;
a-elasticity of the material, unit is MPH. D is the algebraic value of the diameter increase, in units of mm: D is the outer diameter of the ring before cutting, in units of mm
5.3.4 When the residual stress exceeds the standard, the forging should be supplemented with tempering. The tempering temperature is 25% to 50% lower than the tempering temperature of the performance heat treatment. A residual stress test should be done after tempering:
5.4 No-cut inspection
5.4.1 Pickling or magnetic particle inspection
Only two parties can carry out pickling or magnetic particle inspection at the position equivalent to the expanded steel mouth (shaft head or flange). Self-pointing and cracks are not allowed. Magnetic particle inspection is carried out according to the method specified in B/TB46R. 5.4.2 Ultrasonic inspection Ultrasonic flaw detection is carried out according to the methods specified in GB/T1581 and GB/T11345. 5.5 Retest and heat treatment. TB/T1270.-2002 5.5.1 "Mechanical property inspection If the test results of the right sample are not up to date, it is allowed to take two adjacent samples of the sample for retest, but if the mechanical properties are unqualified due to cracks or white spots, retest is not allowed. 5.5.2 If any mechanical property of the forging is unqualified, it is allowed to reheat the forged piece, and the reheated piece should be tested as a new piece. The number of reheat treatments shall not exceed two times (excluding tempering). 6 Acceptance and certificate of conformity 6.1 Magnetic acceptance The forgings shall be inspected by the supplier's quality inspection department according to the requirements of this standard and order drawings. Delivery can only be made after all the requirements of this standard and order drawings are met:
6.2 Certificate of Qualification
When delivering, the supplier must provide the customer with a certificate of qualification, which shall include the following contents: a) Order number:
b) Order drawing number:
Forging number:
d) Plated card number:
e! Chemical composition analysis results:
f3 Mechanical properties test results:
) Non-destructive inspection results (defect distribution map shall be provided if necessary): Center hole inspection report:
Main process parameters of final heat treatment (if required, the welder shall report the welding procedures and the main process parameters of post-weld heat treatment as well as the qualification of the welder)
6.3 Return Policy
After the supplier inspects the forged parts, if the buyer finds any unacceptable defects during the processing, the two parties shall notify the supplier immediately and resolve the issue through negotiation.
7 Marking and Packaging
7.1 The supplier shall mark the contract number, smelting furnace number, and forging card number on the end of the forging that corresponds to the steel chain eyelet, and circle it with white paint. 7.2 After the core hole of the forged parts is inspected and qualified, the inner hole surface shall be coated with anti-lubrication oil. 7.3 The supplier shall package the parts according to the requirements of the shipping route.
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