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JB/T 1270-2014: Shaft forgings for hydraulic turbines and hydraulic generators. Technical specification
Status: Valid JB/T 1270: Evolution and historical versions
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| JB/T 1270-2014 | English | 259 |
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Shaft forgings for hydraulic turbines and hydraulic generators. Technical specification
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JB/T 1270-2014
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| JB/T 1270-2002 | English | 359 |
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Specification for shaft forgings for hydroturbines and hydrogenerators
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JB/T 1270-2002
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| JB/T 1270-1993 | English | 245 |
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Technical conditions for large shaft forgings of turbines and hydro-generators
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JB/T 1270-1993
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PDF similar to JB/T 1270-2014
Basic data | Standard ID | JB/T 1270-2014 (JB/T1270-2014) | | Description (Translated English) | Shaft forgings for hydraulic turbines and hydraulic generators. Technical specification | | Sector / Industry | Mechanical & Machinery Industry Standard (Recommended) | | Classification of Chinese Standard | J32 | | Classification of International Standard | 77.140.85 | | Word Count Estimation | 10,157 | | Date of Issue | 7/9/2014 | | Date of Implementation | 11/1/2014 | | Older Standard (superseded by this standard) | JB/T 1270-2002 | | Quoted Standard | GB/T 223.9; GB/T 228.1; GB/T 229; GB/T 11345-1989; GB/T 20066; JB/T 1581; JB/T 4730.4-2005; JB/T 8468; JB/T 8888; GB/T 4336; GB/T 223.11; GB/T 223.12; GB/T 223.13; GB/T 223.14; GB/T 223.16; GB/T 223.17; GB/T 223.18; GB/T 223.19; GB/T 223.20; GB/T 223.21; | | Regulation (derived from) | Ministry of Industry and Information Technology Notice No. 47 of 2014 | | Issuing agency(ies) | Ministry of Industry and Information Technology | | Summary | This Standard specifies the turbine, turbine generator shaft forgings (including welding shaft, hereinafter referred to as forgings) ordering requirements, manufacturing processes, technical requirements, inspection rules and test methods, inspection and | JB/T 1: ---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Technical conditions for large shaft forgings of turbines and hydro-generators
J 32
Technical conditions for large shaft forgings of turbines and hydro-generators
Released on.1993-09-21
1994-07-01 implementation
Ministry of Machinery Industry of the People's Republic of China
1 Subject content and scope of application
This standard specifies the technical requirements and inspection regulations for large shaft forgings of hydraulic turbines and hydro-generators (including welded shafts, hereinafter referred to as forgings).
Then, test methods, certificates of conformity and signs.
This standard applies to the ordering, manufacturing and inspection of large shaft forgings for hydro turbines and hydroelectric generators.
2 Reference standard
Sample sampling method for chemical analysis of GB 222 steel and chemical composition tolerance of finished products
GB 223 steel and alloy chemical analysis method
GB 228 metal tensile test method
GB 229 metal Charpy (U-notch) impact test method
GB 11345 steel weld manual ultrasonic flaw detection method and flaw detection result classification
Ultrasonic flaw detection method for JB 1581 steam turbine, turbine generator rotor and spindle
Magnetic powder inspection method for JB /ZQ 6101 forged steel parts
3 Ordering requirements
3.1 The purchaser shall specify the forging grade, steel grade, standard number and required supplementary test items in the order contract.
3.2 The purchaser shall provide a delivery pattern indicating the size of the forging of the location of the test specimen for mechanical properties.
4 Technical requirements
4.1 Manufacturing process
4.1.1 Smelting
The steel for forgings shall be smelted in an open hearth or an alkaline electric furnace. Other smelting processes are permitted with the consent of the purchaser.
4.1.2 Cutting the tail
The upper and lower ends of the ingot should have sufficient removal to ensure that the forgings have no shrinkage holes and no serious segregation.
4.1.3 Forging
The entire section of the forging should be fully forged on a forging press with sufficient capacity to make the forging close to the shape and size of the finished product.
The center line of the forging and the ingot should coincide well.
4.1.4 Heat treatment
After forging, the forgings meet the mechanical properties specified in Table 1 after heat treatment.
4.1.5 Welding
4.1.5.1 After the mechanical test of a single forging is passed, the large shaft welding is carried out, and the welding rod with the same mechanical properties as the forging is required.
The best welding specification for welding.
4.1.5.2 Welding method If electroslag welding is used, normalizing and tempering shall be carried out after welding. After tempering, mechanical properties and residuals shall be re-executed.
Force test. If narrow gap automatic welding or other welding methods are used, high temperature stress relief and tempering after welding will be performed, and the stress temperature will be lower than tempering.
When the temperature is 30~50°C, it is not necessary to re-test the mechanical properties. If the tempering temperature is higher than the above temperature, the mechanical properties test should be repeated.
4.2 Chemical composition
The chemical composition of the steel for forgings shall comply with the requirements of Table 2.
4.3 Mechanical properties
4.3.1 The axial mechanical properties of forgings are to comply with Table 1.
4.3.2 When the flange screw hole cannot be nested or does not have the nesting condition, the tangential specimen can be taken on the flange, and the tangential mechanical property is obtained.
Can be no less than the axial performance of the flange part of Table 1.
4.3.3 The flange end axial specimen can also be taken in its extension (the diameter is equal to the shaft diameter), and the mechanical properties are as shown in Table 1 for the performance of the shaft head.
4.3.4 The mechanical properties of the welds of welded large shafts are not lower than those of the shafts in Table 1.
4.4 residual stress
The residual stress value (absolute value) of the forgings shall not exceed 39 MPa.
Note. When there is no major change in the process, the residual stress test may not be performed.
4.5 Non-destructive testing
4.5.1 Forging surface
The surface of the forging should not have visible cracks, folds and other appearance defects that affect the use. Local defects can be cleared but cleared
The depth must not exceed 75% of the finishing allowance. For general defects exceeding the finishing allowance, repair welding is allowed, and serious defects should be obtained.
The purchaser agrees to repair the weld, and the following treatment and inspection should be done after repair welding.
4.5.1.1 After the repair welding, the supplier shall perform the stress relief treatment.
4.5.1.2 For ultrasonic inspection and pickling (or magnetic particle) inspection, there should be no cracks.
4.5.1.3 The hardness in the repair welding zone shall not exceed 50 HBS.
4.5.1.4 Provide inspection records.
4.5.2 Center hole
The inspection result of the forging center hole supplier with the naked eye or the sneak instrument shall meet the following requirements.
a. No cracks, loose or shrinkage holes are allowed on the surface of the center hole;
b. Allow a single, discrete defect with a length of no more than 8 mm (the defect spacing is not less than 5 times the length of the larger defect)
Called a single, discrete defect);
c. Defects accumulated over a large area on an arbitrary 100 cm2 area, the number of defects having a length of 1.5 to 3 mm is not allowed to exceed 20;
d. Do not allow point-like defects that are distributed in chains;
e. When the defect exceeds the standard, the two parties will negotiate.
4.5.3 Pickling or magnetic particle inspection
Forgings are checked by pickling or magnetic powder, and white spots and cracks are not allowed.
4.5.4 Ultrasonic flaw detection
4.5.4.1 For ultrasonic flaw detection of the outer surface of forgings, the results shall comply with the following provisions.
a. Do not allow defects such as white spots, cracks, shrinkage holes, etc.;
b. Defects with an equivalent diameter of less than 5 mm are not counted;
c. Dense defects of equivalent diameters of 5 mm and more are not allowed;
d. It is allowed to have a single, dispersed defect with an equivalent diameter of 6~10 mm, but the spacing between two adjacent defects is not less than 5 times the diameter of the larger defect.
4.5.4.2 Welding shaft welds shall be subjected to ultrasonic flaw detection. The results shall comply with the following requirements.
a. No cracks of any form or direction are allowed;
b. No fusion or incomplete penetration of any part is allowed;
c. Defects with an equivalent diameter of less than 5 mm are not counted;
d. It is allowed to have a single slag and pores of not more than 10 mm in diameter, but the spacing between two adjacent defects should be no less than 5 times the diameter of the larger defect;
e. Allow strip defects of not more than 10 mm in equivalent diameter, but the spacing between two adjacent defects is not less than 50 mm (stripe defect)
a defect whose ratio of length to width is equal to or greater than 3);
f. In a weld of 8 times the wall thickness, the total length of the continuous defect shall not exceed the weld wall thickness.
4.6 Dimensions, tolerances, roughness
4.6.1 Forgings shall be processed in accordance with the dimensions, tolerances and roughness requirements specified in the delivery drawings of the purchaser.
4.6.2 The center hole surface of the forging is fine at the supplier side to a surface roughness Ra of 3.2 μm.
5 Inspection rules and test methods
5.1 Chemical composition analysis
5.1.1 Analysis of molten steel
5.1.1.1 The supplier shall sample and analyze the molten steel in each furnace and report the analysis results. When the ingot is poured from multiple furnace steel, it should
Report weight analysis results should be in accordance with Table 2.
5.1.1.2 If the test and sampling fails or does not meet the analytical requirements, the supplier may take an alternative test at a suitable location near the surface of the ingot or forging.
Determine the composition of molten steel.
5.1.2 Analysis of finished products
The demand can be at the 1/2 wall thickness of the forging extension (hollow forging) or 1/3 radius from the surface (solid forging) or in mechanical properties
Can be sampled for analysis. The results of the analysis should be in accordance with Table 2 and allow for deviations from Table 3.
Table 3 Percentage of allowable deviation of finished product analysis exceeding the specified upper and lower limits
5.1.3 Analysis method
Analyze according to GB 223, or use other methods to ensure the same measurement accuracy.
5.2 Mechanical properties test
5.2.1 Sampling location and quantity
5.2.1.1 When the forgings are flanged at both ends or the ends are not blue, the supplier shall sample at the riser end of the forging, and the demand shall sample at the nozzle end; when the flange is at one end,
Both the supply and the demand are sampled at the flange end and the shaft end.
5.2.1.2 Axial specimens, when sampling at the flange end, drill 4 tensile specimens and 4 impact tests at the flange bolt holes or at the same location.
When the shaft end is sampled, the forging with the center hole is at 1/2 wall thickness, and the solid forging takes 2 tensile specimens at a radius of 1/3 from the surface and
2 impact samples.
The tangential specimen can be cut on the residual stress ring of the flange or at the corresponding part. Two tensile specimens and two impact specimens are taken at the symmetrical position of the ring.
For the weld mechanical properties of the welded large shaft by electroslag welding, the sample was cut on the large-axis forging welding test plate, and two tensile specimens and two impact specimens were made.
5.2.2 Test method and sample size
5.2.2.1 Tensile test method shall be carried out according to GB 228. The sample is a standard sample with a diameter of 10 mm and a gauge length of 50 mm.
5.2.2.2 Impact test method According to GB 229, the sample size is 10 mm × 10 mm × 55 mm.
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-cut method or the ring-shaped resistance strain method.
5.3.2 When using the ring cutting method, when the flange diameter is less than 1250 mm, if the flanges are flanged at both ends, the supplier is at the riser end and the demand side is at the nozzle end.
The outer ring surface of the flange end is cut; if the flange is at one end, it is cut at the outer surface of the flange end.
When the flange diameter is larger than 1250 mm, the outer or inner hole surface of the shaft end can be cut, or the inner surface of the flange can be used.
Cut the ring. The cross section of the ring is 25 mm × 25 mm.
5.3.3 Calculate the residual stress by measuring the average deformation of the ring before and after cutting. The calculation formula is.
5.3.4 When the residual stress is unqualified, the forging shall be supplemented and tempered, and the tempering temperature is 25~50 °C lower than the tempering temperature of the performance heat treatment.
Then do the residual stress test.
5.4 Non-destructive testing
5.4.1 Pickling or magnetic powder
The pick-up test is carried out by the demander at the portion corresponding to the riser of the steel ingot (shaft end or flange end face), and the magnetic powder test is carried out according to the JB /ZQ 6101 method.
5.4.2 Ultrasonic flaw detection
Ultrasonic flaw detection was carried out in accordance with JB 1581 and GB 11345 methods.
5.5 Retest and reheat treatment
5.5.1 Mechanical property test, if one test result does not meet the specified requirements, it is allowed to take two samples adjacent to the test, but
When cracks and white spots appear and the mechanical properties are unqualified, they may not be retested.
5.5.2 If any of the mechanical properties of the forging is unqualified, the forgings are allowed to be reheated. The forged parts after reheating shall be sampled and tested according to the new forgings.
6 Acceptance and Certificate of Conformity
6.1 Acceptance
Forgings shall be inspected by the technical inspection department of the supplier in accordance with the requirements of this standard and the order drawings, and all of them shall be delivered after meeting the requirements of this standard and the order drawings.
6.2 Certificate of Conformity
At the time of delivery, the supplier must provide a certificate of conformity to the acquirer. The certificate of conformity shall include the following.
a. order contract number;
b. Order drawing number;
c. melting furnace number;
d. Forging card number;
e. chemical composition analysis results;
f. Mechanical performance test results;
g. Non-destructive testing results (providing a defect map if necessary);
h. Center hole inspection report;
i. Main process parameters of final heat treatment (when required by the manufacturer, the welding process should report the welding procedure and the main process of post-weld heat treatment)
Parameters and qualification of welding personnel).
6.3 Return Policy
After the forging is inspected by the supplier, if the demander re-inspects and discovers the impermissible defects during the processing, the acquirer shall promptly notify the supplier.
The two sides negotiated a decision.
7 signs and packaging
The supplier shall put the contract number, the melting furnace number, the forging card number on the forging equivalent to the nozzle end of the steel ingot, and use a white paint ring.
After the center hole of the forging is inspected, the surface of the inner hole shall be coated with anti-rust oil.
Additional information.
This standard is proposed and managed by the Deyang Large Casting and Forging Research Institute of the Ministry of Machinery Industry.
This standard was drafted by Qiqihar Casting and Forging Welding Research Institute.
The main drafters of this standard are Wang Changlin, Tang Xinfa, He Enxiang, Zhang Cunfu and Zhou Yunsong.
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