This standard specifies the technical requirements, inspection rules, test methods, certificates and ordering of carbon steel and alloy steel forgings of magnetic rings for steam turbine generators. JB/T 1269-2002 Technical requirements for magnetic ring forgings for steam turbine generators JB/T1269-2002 Standard download decompression password: www.bzxz.net

1CS77.140.85
Machinery Industry Standard of the People's Republic of China
JB/T1269---2002
Replaces JB/T1269-1993
Technical conditions for magnetic ring forgings for turbine generatorsPublished on 2002-12-27
Implemented on 2003-04-01
Published by the State Economic and Trade Commission of the People's Republic of ChinaForeword ,
2 Normative reference documents
3 Ordering requirements
4 Technical requirementsbzxZ.net
4.1 Manufacturing process.
4.2 Chemical composition,
4.3 Mechanical properties,
4.4 Non-destructive testing.
5 Inspection rules and test methods
5.1 Chemical composition analysis,
5.2 Mechanical properties inspection.
5.3 Non-destructive testing:
5.4 Retest and re-heat treatment
6 Acceptance and certificate of conformity
7 Marking and packaging
Table! Mass fraction of chemical composition of steel
Table 2 Upper and lower deviations allowed for finished product analysisTable 3 Mechanical properties
JB/T1269-2002
This standard replaces JB/T12691993 "Technical Conditions for Magnetic Ring Forgings of Steam Turbine Generators". Compared with JB/T1269-1993, the main changes of this standard are as follows: JB/T1269--2002
The overall arrangement and structure of the standard are modified according to GB/1.1-2000 "Guidelines for Standardization Work Part 1: Structure and Writing Rules of Standards":
--Refer to ASTMA288-1991, the following requirements are added for forging manufacturing and inspection: a) For grade 3 retaining rings with a wall thickness greater than 63.5mm, use a steel grade with a Ni content of more than 0.85% by mass; b) The V-notch direction of the Akv impact test specimen is radial. - According to user requirements, a steel grade 30Mn2 is added. For tensile test specimens, a small-size specimen can be used. This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of Deyang Large Castings and Forgings Research Institute. The drafting unit of this standard: Shanghai Heavy Machinery Plant. The main drafter of this standard: Zhang Yongle.
This standard was first issued in 1972, revised for the first time in 1985, and revised for the second time in 1993. I
1 Scope
Technical conditions for magnetic ring forgings for steam turbine generators JB/T1269—2002
This standard specifies the technical requirements, inspection rules, test methods, certificates of conformity and ordering of carbon steel and alloy steel forgings of magnetic rings for steam turbine generators.
This standard applies to forgings such as center rings, fan rings, small retaining rings, and water tank pressure rings of power station steam turbine generators. This standard does not apply to non-magnetic rings.
2 Normative references
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties who 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 documents, 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 methods for steel and alloys JB/T1581 Ultrasonic flaw detection method for turbine and turbogenerator rotor and main shaft forgings JB/T8468 Magnetic particle inspection method for forged steel parts
ASTMA370 Test methods and definitions for mechanical properties of steel products 3 Ordering requirements
3.1 The purchaser shall specify the forging grade, steel used for forgings, standard number and technical requirements adopted, inspection items and other additional requirements in the order contract or drawings.
3.2 The purchaser shall provide ordering drawings of magnetic ring forgings indicating the location of the mechanical properties test specimens. 3.3 The forging grade and steel number shall be marked on the drawing as follows: Steel number
Plated grade × Standard number
4 Technical requirements
4.1 Manufacturing process
4.1.1 Smelting and casting
4.1.1.1 Steel for forgings shall be smelted in an alkaline electric furnace or open hearth furnace. With the consent of the purchaser, other smelting methods may also be used. 4.1.1.2 For grade 3 forgings with a wall thickness of more than 63.5 mm, and grade 4 to 8 forgings, the molten steel used shall be subjected to air treatment, or other refining methods shall be used to remove harmful gases.
4.1.2 Forging
4.1.2.1 Each ingot shall have sufficient removal to ensure the quality of the forgings. 4.1.2.2 Forgings shall be formed on a plating press, forging hammer, or rolling mill with sufficient capacity to ensure that the metal of the entire cross section is fully plated. 4.1.3 Heat treatment
4.1.3.1 Forgings shall be immediately annealed or normalized. 4.1.3.2 Performance heat treatment is annealing plus tempering (normalizing plus tempering may be used for 16Mn), and the final tempering temperature of the forging shall not be less than 560°C. 4.2 Chemical composition
4.2.1 The mass fraction of the chemical composition of steel for silver parts shall comply with the provisions of Table 1, JB/T1269—2002
35SiMn
35CrMo
35CrMoV
25CrNiIMoV
34CrNilMo
34CrNi3Mo
25Cr2Ni4MoV
30Cr2Ni4MoV
When vacuum carbon strand deoxidation is adopted,
the mass fraction of the chemical composition of steel
the silicon content shall not be greater than 0.10%,
For grade 3 retaining rings with a wall thickness greater than 63.5mm, a steel grade containing Ni>0.85% shall be selected. 4.2.2
The allowable deviation of the finished product analysis exceeding the upper and lower limits of the specified value shall comply with the provisions of Table 2. Upper and lower deviations allowed for finished product analysis
Specified
Maximum range
>650~1300
Product cutting area
>1300~2600
0>2600~5200>5200~10300
>10300
Specified
Maximum range
1.01~2.00
≤650
2 (continued)
Product cross-cut area cm2
>650~1300
JB/T1269—2002
>1300~2600>2600~5200>5200~103000.040
Note: The cross-sectional area refers to the maximum cross-sectional area of ​​the forging after rough machining (excluding the center hole), and should be perpendicular to the original ingot or steel axis. 4.3
Mechanical properties
The tangential mechanical properties of the forging should not be lower than those specified in Table 3. Table 3
Forging grade
4.4 Nondestructive inspection
Mechanical properties
4.4.1 Forgings shall not have cracks, scratches, folds, shrinkage holes and other unacceptable defects Recommended steel
16Mn. 45, 30Mn2
>10300
50Mn，1Crl3，35SiMn，35CrMo
35CrMoV. 25CrNiMoV
34CrNi1Mo.34CrNi3Mo
34CrNi3Mo
25CrNiMoV
25Cr2Ni4MoV
30Cr2Ni4MoV
4.4.2 After fine processing by the purchaser, all surfaces shall be subjected to magnetic particle inspection. The length of magnetic traces is not allowed to exceed 4mm. 4.4.3 Forgings should be ultrasonically inspected after performance heat treatment. Initial sensitivity equivalent diameter 2mm: a single defect is not allowed to be larger than the equivalent true diameter 4mm, and a single defect with an equivalent diameter of 2mm to 4mm is allowed to be less than or equal to seven, but the distance between any two adjacent defects should be greater than five times the diameter of the larger defect, and the bottom wave attenuation value caused by the defect is not greater than 6dB. 5 Inspection rules and test methods
5.1 Chemical composition analysis
5.1.1 Melting analysis
The supplier shall take samples of each furnace of molten steel for analysis, and the sampling method for chemical analysis shall comply with GB/T222. 5.1.2 Finished product analysis
The buyer can take one forging from each melting furnace number for finished product analysis. The analysis sample can be taken from 1/2 of the wall thickness of the full-size extension of the forging, or from the mechanical properties sample.
5.1.3 Analysis method
According to the provisions of GB/T223.3~78.
JB/T1269—2002
5.2 Mechanical property test
5.2.1 The supplier shall take a mechanical property test ring at 1/2 of the wall thickness of the extension section at one end of the forging, and take two standard circular tensile specimens with a diameter of 12.5mm and a gauge length of 50mm and two Akv impact specimens at the relative positions of the test rings. If limited by the test block, according to the agreement between the supplier and the buyer, the small-sized tensile specimen in ASTMA370 can also be used. The notch direction of the Akv impact specimen is radial. 5.2.2 The tensile test and impact test shall be carried out in accordance with the provisions of ASTMA370. 5.3 Non-destructive testing
5.3.1 Magnetic particle testing shall be carried out in accordance with the provisions of JB/T8468. 5.3.2 Ultrasonic testing shall be carried out in accordance with the provisions of JB/T1581. 5.4 Retest and reheat treatment
5.4.1 If the test result of any sample does not meet the specified requirements, and the defect is not caused by brittle fracture or cracks of steel, two samples adjacent to the original sample can be taken for double retest. The test results of these two samples should meet the specified requirements. 5.4.2 If the result of any mechanical property sample of the forging still does not meet the specified requirements after the retest, the supplier can reheat treat the forging. The reheat treated forgings shall be sampled and inspected according to 5.2. Without the consent of the purchaser, retreatment shall not exceed two times, but the number of re-tempering of forgings is unlimited.
6 Acceptance and certificate of conformity
6.1 The forgings shall be accepted by the supplier's quality inspection department in accordance with this standard, and the purchaser may retest in accordance with this standard. 6.2 The supplier shall provide the necessary convenience to the purchaser's inspector so that the inspector can witness the acceptance of forgings. The purchaser has the right to select certain items for retest.
6.3 After the supplier has accepted the forgings, if the buyer re-inspects and finds unacceptable defects during the processing, the buyer shall promptly notify the supplier and the two parties shall negotiate to resolve the problem.
6.4 Upon delivery, the supplier must provide the buyer with a certificate of conformity, which shall include the following: a) Order contract number:
b) Order drawing number:
Melting furnace number:
Plated part card number:
e) Standard number:
Forging grade number:
Chemical composition analysis results;
Mechanical properties test results;
i) Non-destructive test results:
Heat treatment status of forgings at delivery.
7 Marking and packaging
7.1 The supplier shall mark each forging with the supplier's factory name or logo, contract number, furnace number, part number, etc., and circle them with white paint. 7.2 The surface of forgings should be coated with a peelable rust inhibitor to prevent corrosion during transportation.
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