This standard specifies the technical requirements, inspection rules, test methods, certificates and marks for the mirror plate forgings of hydro-turbine generators. JB/T 7023-2002 Technical requirements for the mirror plate forgings of hydro-turbine generators JB/T7023-2002 Standard download decompression password: www.bzxz.net

ICS77.140.85
Machinery Industry Standard of the People's Republic of China
JB/T7023-2002
Replaces JB/T7023-1993
Technical conditions for runner plate forgings for hydrogenerators
Specification for runner plate forgings for hydrogeneratorsPublished on 2002-12-27
Implemented on 2003-04-01
Published by the State Economic and Trade Commission of the People's Republic of ChinaForeword
Normative references
Order contents..
Technical requirements.
Manufacturing process
Chemical composition
Non-destructive testing.
Inspection rules and tests Method
Chemical composition analysis,
Ultrasonic flaw detection,
6 Acceptance and certificate
Marking and packaging
Mass fraction of chemical composition
JB/T7023-2002
JB/T7023-2002
This standard replaces JB/T7023-1993 "Technical conditions for mirror plate forgings of hydro-turbine generators". Compared with JB/T7023-1993, the main changes of this standard are as follows: - The open-hearth smelting in 4.1.1 of the original standard has been cancelled; - The S content (mass fraction) in the original standard has been changed from ≤0.025% to ≤0.020%; - The overall arrangement and structure of the standard have been modified in accordance with GB/T1.1-2000 Guidelines for standardization work Part 1: Standard structure and writing rules.
This standard is proposed by China Machinery Industry Federation. This standard is under the jurisdiction of Deyang Large Castings and Forgings Research Institute. The drafting units of this standard are China First Heavy Machinery Group Corporation, Harbin Large Electric Motor Research Institute, and Dongfang Electric Corporation. The main drafters of this standard are Zhang Guoli, Guo Chenghai, Yi Pinfan, and Gu Hongxing. This standard was first issued in 1993.
1 Scope
Technical conditions for mirror plate forgings of hydro-turbine generators
JB/T7023—2002
This standard specifies the technical requirements, inspection rules, test methods, certificates and marks for mirror plate forgings of hydro-turbine generators. This standard applies to the ordering, manufacturing and inspection of mirror plate forgings of hydro-turbine generators. 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 to 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 shall apply to this standard. GB/T222 Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products GB/T223.3～78 Chemical analysis method for steel and alloy GB/T231 Brinell hardness test method for metals
JB4730 Nondestructive testing of pressure vessels
3 Ordering content
3.1 The purchaser shall specify the steel for forgings and the test items other than those required by this standard in the order contract. 3.2 The purchaser shall provide rough machining drawings indicating the dimensions and technical requirements of the forgings (finishing dimensions shall be provided if necessary). 4 Technical requirements
4.1 Manufacturing process
4.1.1 Smelting
Steel for forgings shall be smelted in an alkaline electric furnace. Other smelting methods that meet the requirements of this standard may also be used. 4.1.2 Forging
4.1.2.1 The water and pipe mouths of the steel ingot shall have sufficient removal to ensure that the forgings are free of harmful defects such as shrinkage cavities and severe segregation. 4.1.2.2 During forging, a sufficient forging ratio shall be ensured so that the entire cross section is fully forged. 4.1.3 Heat treatmentWww.bzxZ.net
After forging, the supplier shall perform quenching and tempering or normalizing and tempering treatment to ensure that the forgings have uniform structure and performance, especially to ensure that the bearing surface of the mirror plate has good hardness uniformity. 4.1.4 Processing
After heat treatment of the forgings, the supplier shall perform processing according to the order drawing with appropriate margin. 4.1.5 Stress Relief
After rough machining, the forgings shall be tempered at a temperature at least 30℃ lower than the performance tempering temperature and not less than 550℃ to eliminate stress. 4.1.6 Pre-shipment Processing
After stress relief, the bearing surface of the mirror plate shall be processed to a roughness R. of 1.6um to facilitate the inspection of surface defects by both the supplier and the buyer. 4.2 Chemical Composition
4.2.1 The chemical composition of the steel used for forgings shall comply with the provisions of Table 1. 4.2.2 Other materials may also be used with the consent of the buyer. 1
JB/T7023-2002
0.47~0.55
0.52~0.60
0.37~0.44
Table 1 Mass fraction of chemical composition
0.17~0.37
0.17~0.37
0.17~0.37
0.50~0.80
0.50~0.80
When vacuum carbon deoxidation is adopted, the silicon content shall not be greater than 0.10%, and the manganese content shall be less than or equal to 0.50%. 4.3 Hardness
0.80~1.10
After all heat treatments are completed (including stress relief treatment), the hardness of the mirror plate should reach 190HBS~240HBS, and the hardness difference between any two points on the mirror plate surface should not exceed 20HBS.
4.4 Nondestructive inspection
4.4.1 Forging surface
There should be no visible cracks, folds and other appearance defects that affect the use of the forging surface. Local defects can be removed, but the depth of removal shall not exceed 75% of the finishing allowance
After the mirror plate is finely processed, ground and ground in the power station, there should be no bright spots (hard spots) on the entire bearing surface that affect the use. If there are any, they should be handled through negotiation.
4.4.2 Inclusions
There shall be no single non-metallic inclusion larger than 0.8mm×0.8mm (or corresponding area) on the entire mirror plate bearing surface, or no more than three non-metallic inclusions of the above size within the range of 5mmX5mm (or corresponding area). 4.4.3 Ultrasonic flaw detection
Ultrasonic flaw detection shall be carried out on both planes of the forgings, and there shall be no defects such as white spots, cracks, shrinkage cavities, etc. 5 Inspection rules and test methods
5.1 Chemical composition analysis
5.1.1 The supplier shall take samples of each furnace of molten steel for analysis according to GB/T222 during pouring, and report the analysis results. When multiple furnaces are fired together, the weighted analysis results shall be reported.
5.1.2 If the test and sampling fail, or do not meet the analysis requirements, the supplier may take alternative samples from appropriate locations near the surface of the ingot or forging to determine the chemical composition of the molten steel.
5.1.3 The analysis method shall be carried out in accordance with GB/T223.3~78, or other methods that can ensure the measurement accuracy shall be used. 5.2 Hardness
Check the hardness with a hammer hardness tester or other hardness tester in accordance with GB/T231. When the diameter of the mirror plate is less than or equal to 1500mm, measure the hardness at the average radius of the inner and outer circles of the two planes every 90°: when the diameter is greater than 1500mm, measure the hardness at the average radius of the inner and outer circles of the two planes every 90*. 5.3 Ultrasonic flaw detection
The flaw detection method shall refer to the flaw detection method of pancake parts in JB4730. 6 Acceptance and certificate of conformity
6.1 The forgings shall be inspected by the supplier's technical inspection department in accordance with the requirements of this standard and the order drawing, and the purchaser may conduct re-inspection in accordance with this standard. 6.2 The supplier shall provide the purchaser with a certificate of conformity, which shall include the following: a) Order contract number:
Forging drawing number:
c) Standard number:
Smelting furnace number:
Forging card number:
Chemical composition:
Hardness:
Ultrasonic flaw detection report:
Inclusion inspection report.
Marking and packaging
JB/T7023-2002
The supplier shall stamp the contract number, smelting furnace number, forging card number and other water-permanent steel stamps on the outer cylindrical surface of each mirror plate forging, and circle them with white paint. The supplier shall take necessary protective measures, and the bearing surface of the mirror plate shall be coated with anti-rust oil to prevent the forgings from being damaged and rusted during shipment. The supplier shall package according to the transportation requirements. 7.3
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