JB/T 1268-2002 Technical Specifications for Non-magnetic Guard Ring Forgings for 50MW~200MW Steam Turbine Generators
Some standard content:
ICS77.140.85
Machinery Industry Standard of the People's Republic of China
JB/T1268—2002
Replaces JB/T1268-1993
Specification for nonmagnetic retaining ring forgings for 50MW to 200MW turbine generators
2002-12-27 Issued
2003-04-01 Implementation
Issued by the State Economic and Trade Commission of the People's Republic of China Foreword,
Scope,
Normative references
3 Ordering requirements
4 Technical requirements,
Chemical composition
Mechanical properties,
Residual stress
Grain size.
Non-destructive testing.
Magnetic permeability.
Dimensions and surface roughnesswwW.bzxz.Net
Inspection rules and test methods Method
Chemical composition analysis...
Mechanical properties test,
Residual stress test,
Product particle size determination
Ultrasonic test.
Liquid penetration test
Magnetic permeability determination,
Acceptance and certificate
Marking and packaging
Table 1 Mass fraction of chemical composition
Table 2 Mechanical properties,
JB/T1268—2002
JB/T1268—2002
This standard replaces JB/T1268-1993 (50~2 00MW steam turbine generator non-magnetic guard ring forging technical conditions". Compared with JB/T12681993, the main changes of this standard are as follows: the overall arrangement and structure of the standard are modified according to GB/T1.1-2000 "Guidelines for standardization work Part 1: Structure and writing rules of standards":
The chemical composition of 1Mn18Cr18N steel in 4.2 is N ≥ 0.45%, which is changed to N ≥ 0.47% according to the provisions of Westinghouse PDS10725BM-BSRevPGBU0297/07/17: - For IV and V grades in Table 2 of mechanical properties in 4.3, refer to Westinghouse PDS10725BM-BSRevPGBU0297/07/17. According to the provisions of DS10725BM-BSRevPGBU0297/07/17, some performance indicators are modified:
The stress relief and heat preservation time in 4.1.4.2 is 8h~12h, which is changed to 10h12h according to the provisions of Westinghouse PDS10725BM-BSRevPGBU0297/07/17;
One error in the original text is modified.
This standard is proposed by China Machinery Industry Federation. This standard is under the jurisdiction of Deyang Large Silver Castings Research Institute. The drafting units of this standard are Harbin Large Electric Motor Research Institute and Dongfang Electric Motor Co., Ltd. The main drafters of this standard are Wang Huiting, Li Wenjun, Zhao Hongming, Guo Chenghai, and Xuan Pinfan. This standard was first issued in 1972, revised for the first time in 1985, and revised for the second time in 1993. II
1 Scope
50MW200MW Steam Turbine Generator Non-magnetic
Technical Conditions for Guard Ring Forgings
JB/T1268—2002
This standard specifies the technical requirements, test methods, certificates and marks for non-magnetic guard ring forgings of 50MW~200MW steam turbine generators.
This standard is used for the ordering, production and inspection of non-magnetic guard ring forgings of 50MW~200MW steam 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, the parties to the 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/T223.3~78 Chemical analysis methods for steel and alloys GB/T4338—1995 High temperature tensile test for metal materials (eqvISO738:1989) JB/T4010—1985 Ultrasonic flaw detection method for steel guard rings for steam turbine generators (eqvASTMA531:1974) YB/T5148-1993 Determination of average grain size of metals (eqvASTME112:1981) ASTMA342—1995 Determination of magnetic permeability of weakly magnetic materials ASTMA3701997
Test methods and definitions for mechanical properties of steel products ASTME165—1995 Liquid penetrant testing Test method 3 Ordering requirements
3.1 The purchaser shall specify the adopted standard, forging grade, steel grade, corresponding technical requirements and inspection items, and other additional instructions in the order contract or technical agreement
3.2 When placing an order, the purchaser must provide the supplier with a rough processing drawing (finishing dimensions if necessary), and the sample position shall be marked on the drawing, and marked as follows:
Forging grade × number of this standard
4 Technical requirements
4.1 Manufacturing
4.1.1 Refining
Steel for forgings shall be smelted in electric furnaces, electric furnaces plus electric slag remelting furnaces, or other methods to ensure quality with the consent of the purchaser. 4.1.2 Head and tail cutting
The upper and lower ends of the steel ingot for forgings shall be sufficiently cut off to ensure that the forgings have no shrinkage cavities and unacceptable segregation. 4.1.3 Forging
4.1.3.1 Forging shall be performed on a forging press with sufficient capacity to ensure that the entire cross section of the forging is fully forged. 4.1.3.2 Deformation strengthening shall be performed at room temperature or slightly above room temperature using appropriate strengthening methods, such as die hole expansion, hydraulic bulging or other methods agreed by the purchaser to ensure quality.
4.1.4 Heat treatment
JB/T1268——2002
4.1.4.1 Forgings shall be solution treated after hot forming and before deformation strengthening. 4.1.4.2 After deformation strengthening, forgings shall be heated to 320℃~350℃ at a rate not exceeding 40℃/h and kept at this temperature for 10h~12h, then slowly cooled to below 100℃ at a rate not exceeding 40℃/h and removed from the furnace to eliminate residual stress. 4.1.5 Machining
4.1.5.1 Forgings shall be rough machined before deformation strengthening. 4.1.5.2 Forgings shipped must be processed to the size and surface roughness indicated on the purchaser's drawings. 4.2 Chemical composition
The mass fraction of the chemical composition of steel for steel parts shall comply with the provisions of Table 1. Table 1 Mass fraction of chemical composition
0.40~0.60|17.00~ 19.00|0.30~0.80|0.060|≤0.02550Mn18Crs
0.40~0.60|17.00~19.000.300.800.060≤0.025S0Mn18Cr5
50M18C:4WN0.40~0.6017.00~19.000.30 ~0.80|≤0.060≤0.025
1Ma18Cr18N
17.50~20.00
4.3 Mechanical properties
3.50~6.00
3.50~5.00
MovNBAsBiSnPS6Ti
0.050|0.015 |17.50~20.000.470.030 The mechanical properties of forgings shall conform to those specified in Table 2. 4.4 Residual stress
The residual stress of forgings shall not exceed 20% of the lower limit of the service strength specified in Table 2. 4.5 Grain size
Analysis reference
The grain size of forgings shall be Grade 1 or finer as specified in YB/T5148-1993. If some are smaller than Grade 1, they shall be deemed qualified silver parts without affecting ultrasonic flaw detection.
4.6 Nondestructive testing
4.6.1 Forgings shall not have cracks, folds or other defects that affect use. Local defects on the surface may be removed, but the depth of removal shall not exceed 75% of the finishing allowance.
4.6.2 The supplier shall conduct liquid penetrant testing on the surface of forgings before they leave the factory, and the results shall not show any defects. Local defects may be removed in accordance with the provisions of 4.6.1 of this standard. The buyer shall conduct penetrant testing on the surface of the finished forgings, and the results show that no defects are allowed on the entire finished surface of the guard ring. However, individual defects may be locally polished with the consent of the buyer's design personnel. 4.6.3 Forgings shall be subjected to ultrasonic flaw detection. 4.6.3.1 During shear wave testing, no defect signal exceeding the reference line is allowed. 4.6.3.2 In any full circle of 100mm width, no more than four defect signals are allowed between the reference line and the 1/2 reference line, and the distance between any two adjacent defects shall not be less than 50mm. 4.6.3.3 Guard rings whose V-groove reflection signals cannot be distinguished from the noise level due to coarse grains or microstructure of the guard ring shall be rejected. 4.6.3.4 Longitudinal wave flaw detection does not allow defects larger than 3mm in equivalent diameter, and defects with an equivalent diameter of 2mm to 3mm are less than or equal to four in any full circle of 100mm width.
During longitudinal wave flaw detection, if the bottom wave disappears due to defects, the forging should be unqualified: Table 2 Mechanical properties
≥895
≥760
≥965
≥825
≥900
≥830
790~970
900~~1030
Test temperature ℃
Recommended steel
4.7 Magnetic permeability
50Mn18Cr5
50Mn18Cr5N
Table 2 (continued)
JB/T1268—2002
When 0g, 02, 64, #, it is 95~105
When Agv, it is 20~27
1Mnl8Cr18N
50Mn18Cr4WN
When the magnetic field intensity is 1.6x10*A/m, the magnetic permeability of the forging is not greater than 13.8×10-\H/m4.8Dimensions and surface roughness
The dimensions, tolerances and surface roughness of forgings shall comply with the requirements of the order drawings. 5 Inspection rules and test methods
5.1 Chemical composition analysis
5.1.1 The supplier shall conduct smelting analysis on each furnace of molten steel to determine the percentage of the elements specified in Table 1. The sample shall be taken out when the molten steel is poured. When electroslag remelting is used, the smelting composition of the parent material shall prevail. 5.1.2 The buyer shall conduct a review analysis on the finished product. The sample shall be taken from any point at 1/2 of the wall thickness of the extended section of the forging, or from the mechanical properties sample. 5.1.3 The chemical composition analysis method shall be carried out in accordance with GB/T223.3~78 and relevant analysis methods. 5.2 Mechanical properties inspection
5.2.1 The performance inspection shall be carried out in accordance with the provisions of ASTMA370-1997 and with reference to the provisions of GB/T4338-1995. 5.2.2 Performance specimens shall be prepared after deformation strengthening and stress relief treatment. 5.2.3 The supplier shall cut a mechanical performance test ring at 1/2 wall thickness of the extended section of the forging, and take two tensile specimens at the relative position of the test ring. If there is an impact requirement, take two impact specimens at the relative position of the inner ring. The purchaser shall cut a ring at the other end to take samples for retesting, and the quantity and position are the same as those of the supplier. Both parties shall take an additional magnetic permeability sample on the middle ring. 5.2.4 When the mechanical performance test results do not meet the requirements, it is allowed to take the two adjacent specimens for retesting. If the test fails due to cracks, retesting is not allowed. If there is still one unqualified specimen in the retest results, the forging shall not be used. 5.3 Residual stress test
5.3.1 The residual stress shall be determined by the ring cutting method or other methods agreed upon with the belt party. 5.3.2 Ring cutting method: The supplier and the buyer cut a 25mm×25mm ring at 1/2 wall thickness of the extended section at one end of the forging, measure the average deformation of the ring before and after cutting, and calculate the residual stress. The calculation formula is as follows: O=E/D
Where:
—residual stress, unit is MPa:
E—elastic modulus of the material, unit is MPa: 6--algebraic value of diameter increment, unit is mm: D--outer diameter of the ring before cutting, unit is mm. 5.3.3 For any forging, when the residual stress is unqualified, it is allowed to re-eliminate the residual stress. 5.4 Grain size determination
5.4.1 The grain size test shall be carried out in accordance with the provisions of YB/T5148-1993. 3
JB/T12682002
5.4.2 The grain size sample is taken from the mechanical properties test ring and measured on the radial-longitudinal section. 5.5 Ultrasonic inspection
The ultrasonic flaw detection of forgings shall be carried out in accordance with the provisions of JB/T4010-1985, 5.6 Liquid penetrant inspection
Liquid penetrant inspection shall be carried out in accordance with the provisions of ASTME165-1995, 5.7 Magnetic permeability measurement
The sample and test method shall be carried out in accordance with the provisions of ASTMA342-1995. 6 Acceptance and certificate
6.1 The forgings shall be accepted by the supplier's quality inspection department in accordance with this standard, and the buyer shall re-inspect in accordance with this standard. 6.2 The supplier shall provide the buyer's inspector with necessary convenient conditions so that the inspector can carry out his work. The buyer's inspector shall not cause unnecessary obstruction to the supplier's production. Unless otherwise specified, all inspections shall be carried out at the supplier (except for the recheck analysis test). 6.3 The supplier shall provide the purchaser with a certificate of conformity when the forgings leave the factory. The certificate of conformity shall report the following items: contract number, melting furnace number, standard number, order forging drawing number and grade number: a)
b) Melting analysis results;
Mechanical properties test results:
Product grain size grade
Residual stress measurement results:
Magnetic permeability measurement results;
Liquid penetration test and ultrasonic test results, including defect distribution diagram: Solution treatment and stress relief tempering temperature, holding time and strengthening method: h)
Supplementary required test results.
6.4 After the forgings are accepted by the supplier, if unacceptable defects are found during the purchaser's re-inspection and processing, the purchaser shall promptly notify the supplier and the two parties shall negotiate to resolve.
7 Marking and Packaging
7.1 The supplier shall mark the supplier's factory name or logo, order contract number, order drawing number, smelting furnace number, and silver card number on the nozzle end face of each forging.
7.2 The surface of the forging shall be completely coated with rust inhibitor to prevent corrosion during transportation. 7.3 The packaging and shipment shall avoid damage to the forgings when they are transported to the buyer. 44 If the mechanical property test results do not meet the requirements, it is allowed to take two adjacent samples for retest. If the test is unqualified due to cracks, retest is not allowed. If one sample is still unqualified after the retest, the forging shall not be used. 5.3 Residual stress test
5.3.1 The residual stress shall be determined by the ring cutting method or other methods agreed upon with the belt party. 5.3.2 The ring cutting method is that the supplier and the buyer each cut a 25mm×25mm ring at 1/2 wall thickness of the extended section at one end of the forging, and measure the average deformation of the ring before and after cutting to calculate the residual stress. The calculation formula is as follows: O=E/D
Where:
—residual stress, unit MPa:
E—elastic modulus of material, unit MPa: 6--algebraic value of diameter increment, unit mm: D--outer diameter of the ring before cutting, unit mm. 5.3.3 For any forging, when the residual stress is unqualified, it is allowed to re-relieve the residual stress. 5.4 Determination of product grain size
5.4.1 The test of grain size shall be carried out in accordance with the provisions of YB/T5148-1993. 3
JB/T12682002
5.4.2 The grain size sample is taken from the mechanical properties test ring and measured on the radial-longitudinal section. 5.5 Ultrasonic inspection
Forging ultrasonic flaw detection shall be carried out in accordance with the provisions of JB/T4010-1985, 5.6 Liquid penetrant inspection
Liquid penetrant inspection shall be carried out in accordance with the provisions of ASTME165-1995, 5.7 Magnetic permeability determination
The specimen and test method shall be carried out in accordance with the provisions of ASTMA342-1995. 6 Acceptance and Certificate of Conformity
6.1 The supplier's quality inspection department shall accept the forgings according to this standard, and the buyer shall re-inspect according to this standard. 6.2 The supplier shall provide the buyer's inspector with necessary convenience to facilitate the inspector's work. The buyer's inspector shall not cause unnecessary obstruction to the supplier's production. Unless otherwise specified, all inspections shall be carried out at the supplier (except for review and analysis tests). 6.3 The supplier shall provide the purchaser with a certificate of conformity when the forgings leave the factory. The certificate of conformity shall report the following items: contract number, melting furnace number, standard number, order forging drawing number and grade number: a)
b) Melting analysis results;
Mechanical properties test results:
Product grain size grade
Residual stress measurement results:
Magnetic permeability measurement results;
Liquid penetration test and ultrasonic test results, including defect distribution diagram: Solution treatment and stress relief tempering temperature, holding time and strengthening method: h)
Supplementary requirement test results.
6.4 After the forgings are accepted by the supplier, if unacceptable defects are found during the purchaser's re-inspection and processing, the purchaser shall promptly notify the supplier and the two parties shall negotiate to resolve.
7 Marking and Packaging
7.1 The supplier shall mark the supplier's factory name or logo, order contract number, order drawing number, smelting furnace number, and silver card number on the nozzle end face of each forging.
7.2 The surface of the forging shall be completely coated with rust inhibitor to prevent corrosion during transportation. 7.3 The packaging and shipment shall avoid damage to the forgings when they are transported to the buyer. 44 If the mechanical property test results do not meet the requirements, it is allowed to take two adjacent samples for retest. If the test is unqualified due to cracks, retest is not allowed. If one sample is still unqualified after the retest, the forging shall not be used. 5.3 Residual stress test
5.3.1 The residual stress shall be determined by the ring cutting method or other methods agreed upon with the belt party. 5.3.2 The ring cutting method is that the supplier and the buyer each cut a 25mm×25mm ring at 1/2 wall thickness of the extended section at one end of the forging, and measure the average deformation of the ring before and after cutting to calculate the residual stress. The calculation formula is as follows: O=E/D
Where:
—residual stress, unit MPa:
E—elastic modulus of material, unit MPa: 6--algebraic value of diameter increment, unit mm: D--outer diameter of the ring before cutting, unit mm. 5.3.3 For any forging, when the residual stress is unqualified, it is allowed to re-relieve the residual stress. 5.4 Determination of product grain size
5.4.1 The test of grain size shall be carried out in accordance with the provisions of YB/T5148-1993. 3
JB/T12682002
5.4.2 The grain size sample is taken from the mechanical properties test ring and measured on the radial-longitudinal section. 5.5 Ultrasonic inspection
Forging ultrasonic flaw detection shall be carried out in accordance with the provisions of JB/T4010-1985, 5.6 Liquid penetrant inspection
Liquid penetrant inspection shall be carried out in accordance with the provisions of ASTME165-1995, 5.7 Magnetic permeability determination
The specimen and test method shall be carried out in accordance with the provisions of ASTMA342-1995. 6 Acceptance and Certificate of Conformity
6.1 The supplier's quality inspection department shall accept the forgings according to this standard, and the buyer shall re-inspect according to this standard. 6.2 The supplier shall provide the buyer's inspector with necessary convenience to facilitate the inspector's work. The buyer's inspector shall not cause unnecessary obstruction to the supplier's production. Unless otherwise specified, all inspections shall be carried out at the supplier (except for review and analysis tests). 6.3 The supplier shall provide the purchaser with a certificate of conformity when the forgings leave the factory. The certificate of conformity shall report the following items: contract number, melting furnace number, standard number, order forging drawing number and grade number: a)
b) Melting analysis results;
Mechanical properties test results:
Product grain size grade
Residual stress measurement results:
Magnetic permeability measurement results;
Liquid penetration test and ultrasonic test results, including defect distribution diagram: Solution treatment and stress relief tempering temperature, holding time and strengthening method: h)
Supplementary requirement test results.
6.4 After the forgings are accepted by the supplier, if unacceptable defects are found during the purchaser's re-inspection and processing, the purchaser shall promptly notify the supplier and the two parties shall negotiate to resolve.
7 Marking and Packaging
7.1 The supplier shall mark the supplier's factory name or logo, order contract number, order drawing number, smelting furnace number, and silver card number on the nozzle end face of each forging.
7.2 The surface of the forging shall be completely coated with rust inhibitor to prevent corrosion during transportation. 7.3 The packaging and shipment shall avoid damage to the forgings when they are transported to the buyer. 4
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