SY 5303-1987 General technical requirements for ductile iron castings for petroleum drilling and production machinery products
Some standard content:
Ministry of Petroleum Industry of the People's Republic of China Standard SY5303-87
This standard was confirmed to be valid in 1998, and this is hereby stated. General Technical Conditions for Ductile Iron Castings for Oil Drilling and Production Machinery Products
Published on April 18, 1988
Ministry of Petroleum Industry of the People's Republic of Chinabzxz.net
Implemented on June 1, 1988
Ministry of Petroleum Industry of the People's Republic of China Standard General Technical Conditions for Ductile Iron Castings for Oil Drilling and Production Machinery Products
SY 5303-87
This standard applies to ordinary and low-alloy ductile iron castings for oil drilling and production machinery products. All products without special requirements in product drawings or relevant technical documents shall comply with the provisions of this standard. 1 Grades and Technical Conditions
1.1 Ductile iron grades and corresponding mechanical properties are shown in Table 1. Table 1 Ductile iron grades and mechanical properties
Tensile strengthb
(kg -f/mm°)
QT400-17
QT420-10
QT500-5
QT600-3
QT700-2
QT800-2
400(40.8)
420(42.8)
500(51)
600(61.2)
700(71.4)
800(81.6)
Yield strength
(kg· f/mm*)
245(25)
265(28)
343(35)
412(42)
480(50)
549(56)
Elongation
Impact value αK
(kg·f/em)
147~241
229~302
231~304
241321
“QT” is the first letter of the Chinese pinyin of the word “ball chopsticks”. The number after “QT” represents the minimum tensile strength, and the second number represents the minimum elongation.
1.2 The tensile strength and elongation of the test block are used as the acceptance basis for the mechanical properties of the castings. The yield strength, impact value, and hardness are accepted according to this standard. If there are special requirements for the performance of cast iron parts when the ordering unit makes a request, the ordering unit and the manufacturing unit shall negotiate and stipulate. 1.3 The chemical composition of each grade of ductile iron shall be determined by the manufacturing unit. When there are no special requirements, it will not be used as acceptance basis, but can be used as internal technical data control.
1.4 The metallographic structure of each grade of ductile iron is shown in Appendix A (reference). When there are no special requirements, it will not be used as acceptance basis. 1.5: The mechanical properties specified in this standard can be obtained in the cast state or after heat treatment. 1.6 All castings shall be heat treated to eliminate internal stress. 1.7 The dimensional tolerance, tolerance grade, quality deviation, processing allowance, etc. of castings shall comply with the provisions of this standard. When there are special requirements in the drawings and ordering technical conditions, they shall be negotiated and stipulated by the supply and demand parties. 1.8 The machining allowance of castings shall be in accordance with Appendix B (reference parts). When there are special requirements in the drawings and ordering technical conditions, they shall be in accordance with the drawings and ordering technical conditions.
1.9 The dimensional tolerances and tolerance grades of ductile iron castings are shown in Tables 2 and 3. Approved by the Ministry of Petroleum Industry of the People's Republic of China on April 18, 1988 and implemented on June 1, 1988
SY 5303-87
Table 2 Tolerance values of casting dimensions
2. Valley
① CT1 to CT4 do not specify tolerance values, which are reserved for the possibility of requiring tighter tolerances in the future. Note
② CT13 to CT15 are the basic dimensions of castings less than or equal to 16 mm. Their tolerance values need to be marked separately and can be increased by 2 to 3 levels. Table 3 Tolerance grades of casting dimensions
Casting process
Mass production
Single piece production
Handmade sand mold
Sand mold machine selection and shell mold
Low pressure casting
Pressure casting
Investment casting
Molding materials
Wet and dry sand
Self-hardening sand
Tolerance grade CT
Tolerance grade CT
Note, the tolerance grades in Table 3 are applicable to basic dimensions greater than 25mm. For basic dimensions of castings less than or equal to 25mm, the following more precise tolerance grades are usually adopted:
① When the basic dimension of the casting is less than or equal to 10mm. Its tolerance grade is increased by three grades. When the basic dimension of the casting is greater than 10mm and equal to 18mm, its tolerance grade is increased by two grades. When the basic dimension of the casting is greater than 16mm and equal to 25mm, its tolerance grade is increased by one grade. 2
SY5303—87
1.9.1 The basic dimension of the casting is the dimension given on the casting drawing, including the machining allowance. 1.9.2 The inspection of castings should be based on the "main dimensions". The "main dimensions" refer to the machining and non-machining surfaces related to assembly and affecting the performance.
1.9.3 For non-machining wall thickness and rib thickness, the dimensional tolerance is allowed to be expanded by one grade of tolerance value according to the selected tolerance grade of the casting. 1.9.4 Different parts of the same casting are allowed to use different tolerance grades, but it should be indicated in the drawings or relevant technical documents. 1.9.5 The dimensional tolerance of the casting should be symmetrically distributed. When there are special provisions, it should be marked directly after the basic dimension of the casting. 1.10 The misalignment value of the casting on the machined surface shall not exceed one-half of the machining allowance at that location, and an additional allowance of not less than 2 mm shall be guaranteed. On the non-machined surface, it shall not exceed the corresponding dimensional deviation or the deviation of wall thickness and rib thickness. If necessary, it can be agreed upon by both the supplier and the buyer. The allowable deviation of the concave platform (or overlap) of the casting shall comply with the provisions of Table 4. 1.11
Table 4 Allowable deviation of the convex platform of the casting
>10~30
>30-80
+1.5.—1.0
+2, —1.5
1.12 The flatness (including bending and deflection) of the casting surface shall be measured according to the maximum size of the inspected surface. On the machined surface, a machining allowance of not less than 2 mm shall be guaranteed, and on the non-machined surface, it shall comply with the provisions of Table 5. Table 5
Large size of the forged surface to be inspected
Flatness
260~500
>500~800
>800~1250
1.13 The mold sand and core sand on the casting should be cleaned up. The pouring pipe mouth, fleshy blisters, etc. should be scraped and polished, with smooth transition. The residual traces after the riser is removed are allowed to protrude or recess 1.5mm on the non-working surface if it does not affect the appearance and performance. On the processing surface, it should comply with the provisions of Table 6.
The root of the mouth
Maximum size
>50-100
shall not exceed two-thirds of the processing allowance, and there shall be at least 2m of processing allowance1.14 The casting shall not have cracks, shrinkage holes, severe shrinkage and damage, etc. that affect the strength, performance, processing performance and seriously affect the appearance. For defects that can still be repaired, it is allowed to use coal filling or other methods to repair, but it must comply with the requirements of the drawings or the technical conditions of the order.
1.15 All casting fillets not indicated on the drawings shall be manufactured according to R3mmR8mm. 1:16·The quality deviation of the casting shall be controlled within the range specified in Table 7, but it is generally not used as a basis for scrapping. 3
100-~500
>5001000
$Y 6303—87
Note: ① The nominal mass is the mass including the machining allowance and process correction of the casting. It can be determined by the calculated value or the measured average value taken from a batch of qualified cast iron.
② The level deviation is used for castings with strict requirements on casting quality. The level 2 deviation is used for castings produced in large batches; the level 3 deviation is used for parts produced in small batches of single pieces.
① The negative adjustment limit of the lower deviation of the casting quality deviation is .1 All casting surfaces shall be painted with red primer, but hot-drying parts and cast surfaces are not allowed to be painted with red primer. 2 Acceptance rules and test methods
2.1 The castings shall be inspected and accepted by the technical inspection department of the manufacturing unit according to the technical conditions. The inspection method shall be stipulated by the manufacturing unit. The ordering unit has the right to conduct random inspection or re-inspection of the casting quality. 2.2 The appearance quality of the castings shall be inspected piece by piece. 2.3 The geometric dimensions of the casting shall be based on the "main dimensions" marked on the drawings as the acceptance criteria. In addition to the first piece being marked for inspection, the general quality-assured parts shall be inspected regularly or in batches by the inspection department. The inspection rate shall not be less than 5%, and each batch shall be at least three pieces. The main parts shall be regularly inspected by marking or dissecting.
2.4 When conducting mechanical property tests, the methods and numbers are as follows. 2.1. When producing single-piece small batches, at least one group of test pieces shall be taken from each package of iron. Three tensile specimens shall be made from one group of test pieces. If impact test is required, six impact specimens shall be made.
2.4.2 When producing in batches, under the condition that the raw materials and production process are stable, at least one mechanical property test shall be carried out for each batch of castings. The sampling method and quantity shall be carried out in accordance with 2.4.1. The quality of other batches shall be controlled by metallography or other methods. 2.4.3 The test pieces can be cast in dry or wet molds, and generally should be poured in the middle or late stage of each package. When producing lead parts by metal molds, centrifugal casting and other methods, the sampling method of the test pieces can be indicated in the drawings or ordering technical conditions. 2.5 Important castings with special requirements for physical and chemical properties shall be inspected according to the provisions of the drawings and relevant technical documents. 2.6 For castings that require heat treatment, the test pieces (or test pieces) shall be heat treated in the same furnace as the parts. If the failure is caused by improper heat treatment, it is allowed to be treated again and re-tested.
2. When checking the mechanical properties of castings, the test block shown in Figure 1 is generally used, and the test environment shown in the figure can also be used, and the casting body is allowed to be sampled. For thick parts, the test block (or sample) can be determined by negotiation between the supply and demand parties. 2.9 Tensile test is carried out in accordance with GB228-70 "Tension Test Method". The sample is shown in Figure 3. Two are made for the first time: if both are qualified, they are qualified. If one is unqualified, the third one should be tested again. If it is qualified, it is qualified, otherwise it is unqualified. 2.9 Supplementary impact test is carried out in accordance with B229-B3 "Metal Normal Temperature Impact Toughness Test Method" The sample is shown in Figure 4. Impact test specimens are grouped into three, two of which are qualified. When repeated tests are carried out, three are required to be qualified. 2.10 Hardness test is carried out in accordance with GB2$1-84 "Metal Brinell Hardness Test Method", and the sample is taken from the end of the tensile test specimen. If the hardness is to be measured on a casting, the test location can be agreed upon by the ordering unit and the manufacturing unit. 2.11 Nondestructive testing should be performed on each ductile iron with requirements. 3 Factory Marks and Certificates 3.1 Qualified castings must be marked with the manufacturer's mark. 3.2 When castings leave the factory, a quality manual should be attached. The contents of the manual include: a. The name and trademark of the manufacturer, b. Casting drawing number or part number, c. Ductile iron grade and mechanical properties.
In addition to the above items, the ductile iron qualification certificate shall also include the test results of the items if there are special provisions in the ordering technical conditions.
SY530387
Appendix A
Metallurgical structures of various grades of ductile iron
(Test piece)
A1 The metallographic structures of various grades of ductile iron are shown in Table A1. Table A1
Pearlite
QT400-17
QT420-10
QT500-5
QT600-3
QT700-2
QT800-2
Ferrite
Ferrite + pearlite
>80Fine flakes]
>85Fine flakes
Bull's eye shape
And blocky
Dispersed shape
Note, ① There should be no ternary phosphorus eutectic-paint carbon complex and network phosphorus eutectic. Phosphorus eutectic
(②Spheroidizing level is evaluated according to JB1802-76 Rare Earth Magnesium Ball Wall Cast Iron Metallographic Standard" Cementite
Phosphorus eutectic
Cementite
Spheroidizing level (higher or equivalent
The machining allowance of castings is shown in Table BI.
Basic size of castings
>50-120
>120~250
250-630
>630~1000
10001600
>16002500
22500~4000
24000-6300
Additional instructions:
SY 5303--87
Appendix B
Machining allowance of castings
(reference)
This standard is proposed by the Manufacturing Department of the Ministry of Petroleum Industry. 9
This standard is under the jurisdiction of the Standardization Committee for Petroleum Exploration and Development Equipment and Materials. The responsible drafting unit of this standard is the Fourth Petroleum Machinery Factory of the Ministry of Petroleum Industry. The main drafter of this standard is Zhang Zhaoqing.
Top. Bottom,
, bottom,
Pre-, bottom,
Top, bottom,
Pre-, rust,
Top, bottom,
Item, bottom,
Top, bottom,
Top, bottom
Item, bottom,
This standard continues to be effective after the review in 199, and the review result has been approved by the State Administration of Petroleum and Chemical Industry.Casting drawing number or part number
c. Ductile iron grade and mechanical properties.
In addition to the above items, the ductile iron qualification certificate shall also include the test results of the items if there are special provisions in the ordering technical conditions.
SY530387
Appendix A
Metallurgical structures of various grades of ductile iron
(Test piece)
A1 The metallographic structures of various grades of ductile iron are shown in Table A1. Table A1
Pearlite
QT400-17
QT420-10
QT500-5
QT600-3
QT700-2
QT800-2
Ferrite
Ferrite + pearlite
>80Fine flakes]
>85Fine flakes
Bull's eye shape
And blocky
Dispersed shape
Note, ① There should be no ternary phosphorus eutectic-paint carbon complex and network phosphorus eutectic. Phosphorus eutectic
(②Spheroidizing level is evaluated according to JB1802-76 Rare Earth Magnesium Ball Wall Cast Iron Metallographic Standard" Cementite
Phosphorus eutectic
Cementite
Spheroidizing level (higher or equivalent
The machining allowance of castings is shown in Table BI.
Basic size of castings
>50-120
>120~250
250-630
>630~1000
10001600
>16002500
22500~4000
24000-6300
Additional instructions:
SY 5303--87
Appendix B
Machining allowance of castings
(reference)
This standard is proposed by the Manufacturing Department of the Ministry of Petroleum Industry. 9
This standard is under the jurisdiction of the Standardization Committee for Petroleum Exploration and Development Equipment and Materials. The responsible drafting unit of this standard is the Fourth Petroleum Machinery Factory of the Ministry of Petroleum Industry. The main drafter of this standard is Zhang Zhaoqing.
Top. Bottom,
, bottom,
Pre-, bottom,
Top, bottom,
Pre-, rust,
Top, bottom,
Item, bottom,
Top, bottom,
Top, bottom
Item, bottom,
This standard continues to be effective after the review in 199, and the review result has been approved by the State Administration of Petroleum and Chemical Industry.Casting drawing number or part number
c. Ductile iron grade and mechanical properties.
In addition to the above items, the ductile iron qualification certificate shall also include the test results of the items if there are special provisions in the ordering technical conditions.
SY530387
Appendix A
Metallurgical structures of various grades of ductile iron
(Test piece)
A1 The metallographic structures of various grades of ductile iron are shown in Table A1. Table A1
Pearlite
QT400-17
QT420-10
QT500-5
QT600-3
QT700-2
QT800-2
Ferrite
Ferrite + pearlite
>80Fine flakes]
>85Fine flakes
Bull's eye shape
And blocky
Dispersed shape
Note, ① There should be no ternary phosphorus eutectic-paint carbon complex and network phosphorus eutectic. Phosphorus eutectic
(②Spheroidizing level is evaluated according to JB1802-76 Rare Earth Magnesium Ball Wall Cast Iron Metallographic Standard" Cementite
Phosphorus eutectic
Cementite
Spheroidizing level (higher or equivalent
The machining allowance of castings is shown in Table BI.
Basic size of castings
>50-120
>120~250
250-630
>630~1000
10001600
>16002500
22500~4000
24000-6300
Additional instructions:
SY 5303--87
Appendix B
Machining allowance of castings
(reference)
This standard is proposed by the Manufacturing Department of the Ministry of Petroleum Industry. 9
This standard is under the jurisdiction of the Standardization Committee for Petroleum Exploration and Development Equipment and Materials. The responsible drafting unit of this standard is the Fourth Petroleum Machinery Factory of the Ministry of Petroleum Industry. The main drafter of this standard is Zhang Zhaoqing.
Top. Bottom,
, bottom,
Pre-, bottom,
Top, bottom,
Pre-, rust,
Top, bottom,
Item, bottom,
Top, bottom,
Top, bottom
Item, bottom,
This standard continues to be effective after the review in 199, and the review result has been approved by the State Administration of Petroleum and Chemical Industry.
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