JB/T 9630.1-1999 This standard is a revision of ZB K54 004-87 "Magnetic Particle Inspection and Quality Grading Method for Steam Turbine Steel Castings". This standard specifies the method of magnetic particle inspection of steel castings and the method of grading defects. This standard is applicable to the inspection of surface and near-surface defects and the assessment of quality grades of major steel castings for steam turbines. When adopting this standard, a magnetic particle inspection map of steel castings must be provided, and the map should indicate the parts requiring inspection and the corresponding quality grades. This standard was first issued on March 21, 1988. JB/T 9630.1-1999 Magnetic Particle Inspection and Quality Grading Method for Steam Turbine Steel Castings JB/T9630.1-1999 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T 9630.1-1999
Magnetic particle testing and quality classification methods of steel castings for steam turbines
Magnetic particle testing and quality classification methods of steel castings for steam turbines1999-08-06 Issued
State Bureau of Machinery Industry
2000-01-01 Implementation
JB/T9630.1—1999
This standard is a revision of ZBK54.004—87Magnetic particle testing and quality classification methods of steel castings for steam turbines. The technical content of this standard is basically the same as the original standard, with only a few modifications. This standard replaces ZBK54004—87 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Standardization of Steam Turbines. This standard was drafted by Harbin Steam Turbine Co., Ltd., Shanghai Steam Turbine Co., Ltd., and Shanghai Power Equipment Complete Design Institute. The main drafters of this standard are Cong Caiyuan and Wang Sanbai. This standard was first issued in March 1988. 1 Scope Machinery Industry Standard of the People's Republic of China Magnetic Particle Testing and Quality Classification Methods of Steel Castings for Stean Turbines This standard specifies the magnetic particle testing and quality classification methods of steel castings for stean turbines. JB/T9630-1—1999 Replaces ZB K54 00J—87 This standard applies to the inspection of surface and near-surface defects and the assessment of quality grades of main steel castings for steam turbines. When adopting this standard, the magnetic particle inspection of steel castings must be grasped. The drawing should indicate the parts requiring inspection and the corresponding quality level. 2 Referenced standards
The provisions contained in the following international standards constitute the text of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised. The parties using this standard should explore the possibility of using the latest versions of the following international standards. GB/T9445-1988 General Rules for Technical Qualification Appraisal of Nondestructive Testing Personnel JB/T8290--1995 Magnetic Particle Inspection Machine
3 Safety
To prevent hazards such as electric shock and ultraviolet rays, inspection personnel must be equipped with protective equipment and conduct inspections in a place suitable for magnetic particle inspection according to relevant operating procedures.
4 Personnel Qualification
Inspection personnel should obtain technical qualification certificates in accordance with the provisions of GB/T9445 and engage in work corresponding to their level. 5 Inspection equipment and materials
5.1 Magnetic particle inspection machine
Magnetic particle inspection machine shall be able to provide continuously adjustable half-wave or full-wave DC current of sufficient intensity and have demagnetization function. Other performances shall comply with the provisions of JB/T8290.
5.2 Magnetic powder
5.2.1 Magnetic powder can be non-fluorescent magnetic powder or fluorescent magnetic powder. 5.2.2 The color of the magnetic part shall have a clear contrast with the color of the inspection surface. 5.2.3
The particle size and magnetic weighing of the magnetic part are shown in Table 1. Table 1 Particle size and magnetic weighing of magnetic components
Blue powder type
Particle size μm
Invitational weighing B
5.3 Magnetic suspension
Non-luminous silicon powder
Magnetic powder for dry powder method
Approved by the State Machinery Industry Bureau in 1999-08-06 Magnetic powder for developing powder method
72~-48
Fluorescent spot powder
Nourishment component for dry powder method
Base powder for developing component method
Implementation in 2000-01--01
JB/T 9630.1-1999
Magnetic suspension is made of magnetic powder, activator, wetting agent, preservative and carrier liquid in appropriate proportions. The concentration of non-fluorescent magnetic fundamental wave is generally 7~15g/L, and the concentration of fluorescent magnetic suspension is generally 0.5~2/L, which can be appropriately selected according to the state of the surface to be inspected. 6 Preparation of the surface of the strong inspection piece
6.1 Cast steel parts should be subjected to final heat treatment before magnetic particle inspection. 6.2 The inspection surface must be machined or ground, shot peened (the diameter of the steel furnace shall not be greater than 1.5mm). The maximum allowable value of the roughness Ra of the machined surface is 6.3um; the maximum allowable value of the roughness Ra of the casting surface after grinding and polishing is 12.5m. Stone.3 The inspection surface shall not have impurities such as coating, paint, sticky sand, loose nitrided skin, etc. that affect the inspection effect. 7 Inspection method
7.1 Magnetization
7.1.1 Magnetization method
It is recommended to use the contact continuous method. When the sensitivity meets the requirements, other methods can also be used. 7.1.2 Magnetization specification
7.1.2.1 When the contact continuous method is used, the contact spacing should generally not exceed 250mm, and the shortest spacing should not be less than 75mm. The magnetization specification is that the magnetization current is not less than 40A for every 10mm of contact spacing. The magnetization current must be full-wave or half-wave DC: 1.2.2 When other methods are used for magnetization, the magnetization specification can be determined by testing. 7.1.3 Magnetization direction
Magnetization should be carried out at least once in two mutually perpendicular directions in order to detect defects in different directions. When magnetizing by the contact method, it is recommended to use the two-clock method shown in Figure 1, and the overlap should be more than 25mm. Double shadow
Square CC (self-line)
iti rnm
a>Diagonal method
6) Double rectangle method
Figure 1 Contact method Magnetization method
7.2 Display method
7.2.1 Dry powder method or wet powder method can be used to display defect magnetic traces. x
7.2.2 The application of magnetic powder or magnetic suspension should be carried out while the inspected position is subjected to the external magnetic field. After the magnetic powder or magnetic suspension is evenly distributed on the inspected surface, the external magnetic field is cut off.
了.3 Crack sensitivity
7.3.1 In order to comprehensively evaluate whether the magnetization method, magnetization specification, magnetic powder, flaw detection equipment performance and operation are appropriate, a sensitivity test should be carried out before the formal start and end of magnetic powder flaw detection. 7.3.2 Sensitivity verification can use the octagonal sensitivity test piece shown in Figure 2. During the calibration, the test piece is placed at the place where the magnetic field is weakest. One side of the carbon steel sheet should be close to the exposed surface.
JB/T* 9630. 1-1999
Contains a block of carbon steel sheets welded together
The non-ferrous metal through-axle is connected by a machine. The non-ferrous metal handles of appropriate length
The copper plate thickness is about 5.25mm
Figure 2 Sensitivity test piece
7.3.3 After magnetization and application of magnetic powder or magnetic suspension, if six magnetic traces can be clearly shown on the back of the test piece, the sensitivity is recognized. Otherwise, the magnetization direction, magnetization specification or magnetic suspension concentration should be adjusted to meet the sensitivity requirements, and the flaw detection part before this calibration should be re-tested.
7.4 Observation of magnetic traces
7.4.1 The observation of magnetic traces should be carried out immediately after the traces are formed. 7.4.2 When non-fluorescent magnetic powder is used, it must be observed under sufficient brightness. When fluorescent magnetic powder is used, it should be observed in a dark place under a black light with a wavelength of 0.32~0.40m.
8 Defect types
The magnetic traces determined to be defects after analysis can be classified according to their shape, length, distribution density, location and degree of magnetic accumulation, and refer to the photos in Figures 3 and 4. a) Cracks:
b) Linear defects: Non-crack defects with a length greater than three times the width: If there are two or more linear defects on a straight line, with a length greater than or equal to 1.5 mm and a spacing less than 2 mm, it can be seen as a defect, and its size is the sum of the length and spacing of each defect magnetic trace. When a single line is scattered, its size is the length of the defect magnetic trace.
e) Shrinkage cavities and shrinkage porosity;
According to the comparison of the severity of the defects with the reference photos in Figures 3a), 3b), and 3c), the evaluation is I-1, I-2, and I-3. d) Slag inclusions;
According to the comparison of the severity of the defects with the reference photos in Figures 4a), 4b), and 4c), the evaluation is T-1, II-2, and 1-3. e) Single pores t
There are two or more single pores on a straight line, and the major diameter is greater than or equal to 1.5mm, when the spacing is less than 2mm, it can be regarded as a pore, and its size is the sum of the long diameters of all pores. f) Dense pores;
If there are more than 10 pores with a long diameter greater than or equal to 1.5mm in any area of ​​50mm×50mm, it can be regarded as dense pores.
) Unmelted core foreign iron, inner chiller.
JB/T 9630.1-1999
Figure 3a] Shrinkage and shrinkage hole - 1st level reference photo
Figure 3c) Shrinkage and shrinkage hole [-2nd level reference photo JB/I 9630.1-1999
Figure 3a] Shrinkage and shrinkage hole - 1st level reference photo
Figure 3c) Shrinkage and shrinkage II - 3rd level reference photo
Figure 4a] Sharp inspection and inspection [level 1st level reference photo
JB/T 9630.1-1999
Figure 4b Slag inclusion - 2nd level reference photo
Figure 4] Slag inclusion - 3rd level reference photo
9 Quality grades
9.1 Classification of quality grades
JB/T 9630. 1—1999
The quality grades of magnetic particle inspection of main steel castings are divided into five grades according to the defect type and degree, as shown in Table 2. Table 2 Quality grades of magnetic particle inspection of main steel castings Quality
Defect type
Linear defect
Shrinkage cavity
Single pore
Dense nest gas piercing
Unmelted core support, internal cold defect
9.2 Selection of quality grade
Machinery surface
Not allowed
Not allowed
Not allowedbzxz.net
Manufactured surface
The selection of quality grade should be determined according to the specific conditions such as the use requirements of the casting. In general, the machined surface of important parts of steel parts is recommended to be grade 1, the machined surface of general parts can be grade 2, the manufactured surface of important parts can usually be grade 3, and the casting surface of other parts can be grade 4 or 5. For castings with special requirements, additional quality grades can be selected. Defect treatment
Defects beyond the quality grade requirements can be eliminated by appropriate methods. If the depth of the eliminated part is greater than the allowable tolerance, it should be repaired by welding. The eliminated and repaired welded areas shall be re-inspected and evaluated according to the same quality level. The inspection report shall include the following contents:
e) Ordering unit and contract number or entrusting unit, report number and issue date; b) Name, drawing number, furnace number, number, material and heat treatment status of steel casting; c) Magnetic particle inspection equipment model, magnetization method and specification, magnetic particle model, precision calibration results and inspection surface status; d) Gearing results and conclusions. For defects exceeding the specified quality level, the location, shape and size of the defects shall be drawn with diagrams; e) Signature of the inspector!
[Other necessary matters,
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