JB/T 9742-1999 This standard is a revision of NJ 308-86 "Technical Conditions for Gray Cast Iron Cylinder Head and Engine Block Castings". During the revision, only editorial modifications were made in accordance with relevant regulations, and the main technical content remained unchanged. This standard specifies the technical requirements, inspection methods, inspection rules and marking, packaging, transportation and storage of gray cast iron cylinder heads and engine block castings for internal combustion engines. This standard is applicable to non-alloy and low-alloy gray cast iron cylinder heads and engine block castings for internal combustion engines with a cylinder diameter less than or equal to 200mm. Similar castings of other models can also be used for reference. This standard was first issued in 1984. JB/T 9742-1999 Technical Conditions for Gray Cast Iron Cylinder Head and Engine Block Castings for Internal Combustion Engines JB/T9742-1999 Standard download decompression password: www.bzxz.net

1CS27.020
Machinery Industry Standard of the People's Republic of China
JB/T97421999
Internal combustion engines
Gray iron cylinder head and eylinder block castings-Specifications1999-09-17Promulgated
National Machinery Industry Standard
2000-01-01Implementation
JBT9742-1999
This standard is a revision of NI308-86 "Technical Specifications for Gray Iron Cylinder Head and Eylinder Block Castings". The revision made editorial changes to the original standard, and the main technical content did not change. This standard replaces NI308-86 from the month of implementation. This standard is issued and managed by the National Technical Committee for Standardization of Internal Combustion Engines. This standard was initiated by: Wuxi Diesel Engine Body Factory, Shanghai Internal Combustion Engine Research Institute. The main authors of this standard are: Shi Jianfang, Wei Yadao, Shi Shaoqiu. This standard was issued in 1984.
1 Scope
Machinery Industry Standard of the People's Republic of China
Internal Combustion Engine: Technical Conditions for Gray Cast Iron Cylinder Head and Block Castings
[Internal Combustion Engine-Gray Iron Cylinder Head and Cylinder Block CAG TMG6
Specification
JEr9742-1999
Replaces N1308-85
This standard specifies the technical requirements, inspection methods, inspection regulations and marking, packaging, transportation and storage of gray cast iron cylinder head and block castings for internal combustion engines.
This standard is applicable to non-alloy and low-alloy cast iron gas castings and machine parts of internal combustion engines with a cylinder true diameter of less than or equal to 2m. Similar castings of other models can also be used for reference. 2 Reference standards
The meanings contained in the following standards constitute the provisions of this standard through their use in this standard. When this standard is published, the latest version is valid. All standards are subject to revision. Each party using this standard should explore the possibility of using the following standards and new versions. GBIT23—1984
G8/T:9439-1988
JB/T 794S[999
Technical requirements
3.1 Quality of castings
Metal Brinell compaction test method
Gray casting missing parts
Mechanical parts performance test method
3.1.1 The grade of cast iron used for the oxygen cover and the body shall not be lower than the grade HT200 specified in GB＇9439, and the tensile strength of the test specimen cut from the test bar with a diameter of 30mm (see Case B in 5.3.1) shall be the basis for acceptance. , its total resistance is greater than or equal to 200MPa
3.1.2 When the supply and demand parties agree, the tensile strength of the sample taken from the casting can also be used as the test basis: According to the structure and casting characteristics of the cylinder head and the engine, the tensile strength of each part of the body of the part is generally lower than the tensile strength of the single casting test piece with a diameter of 30mm. Table 1 shows the tensile strength that can be obtained by casting the cylinder head and the body of the engine for reference by the design personnel and the supply and demand parties. The casting design should be carried out according to the measured values ​​of the relevant parts. 3.1.3 The hardness of the two planes where the engine body and the cylinder head meet should be used as an inspection item: its hardness value should reach 170-241HBS. [The hardness difference of the same cylinder head and engine block should be less than 50HBS. 3.1.4 If the purchaser requires special inspection of the strength, hardness and metallographic structure of the casting body and the attached test block, the following contents should be clearly and specifically described in words or in graphics in the drawings and relevant technical documents: a) the sampling inspection position or the attached test block, shape and size; b) the specific performance indicators of the inspection position and test sample: approved by the State Administration of Machinery Industry 999-09-17
2000-01-0# actual
) the inspection frequency or sampling percentage
JB/T9T4z-1999
3.1.5 After negotiation between the supply and demand parties, the supplier shall meet the special requirements of the product. If the purchaser does not make any special requirements: according to 3.1.1.
3.1.6 If there is no special requirement, the chemical composition of the casting shall not be used as the basis for acid acceptance. In addition to meeting the requirements of this standard, castings shall also meet the specific requirements of the special sample. 3.1.7
Table 1 Grey cast iron cylinder and body casting body test specimen strength performance Part iron grade
3.1 Casting size and crown deviation
> 20-30
>20-30
>30-50
Tensile strength
1.1 The tolerance of the basic size of castings (including processing quantity and process addition) shall meet the tolerances of grades 9 to 11 in Table 2. Table 2 Tolerances of castings
Basic size of castings
>10-16
>15-25
>25-40
>40-63
>63-100
100~150
> 160-250
5 250-400
400-30
630~1000
000600
>1 600~2 500
JR/T9742—1999
2.2 The tolerance band should be symmetrically arranged on the basis of half of the dimension, and the other half should be negative. However, in special cases, asymmetric arrangement is adopted, and part or all of the tolerance should be positive or negative. 1.2.3 The wall thickness tolerance of the casting should be lowered by one level according to the basic size selected for the casting in Table 2. 3.7.4 The value of the casting can be selected according to the determined tolerance grade, which should generally not exceed 1.5mm. When hand molding is adopted or the maximum size of the sand box exceeds 1500, the rotation error can be appropriately increased, but the maximum should not exceed 2mm, and the error should not be different from the tolerance value listed in Table 2.
3.2.5 The weight difference of castings should not exceed ±5%. 3.3 Manufacturing defects and external quality of missing parts
3.3.1 The replacement parts are not allowed to have defects 3.3.1.! Missing parts are not allowed to have cracks, insufficient porcelain, severe adhesion and other casting defects that reduce the structural strength of castings or affect the positioning of parts before cutting.
3.3.1.2 The surface of the cylinder head combustion chamber, the cone surface of the valve seat, the spark hole, the blast hole, the sealing surface of the fuel injection nozzle and the range of the cylinder bore diameter are not allowed to have defects that cannot be removed by machining. 3.3.1.3 The intake and exhaust ducts of the replacement cylinder head are not allowed to have sand adhesion, shaving, other defects that affect the intake and exhaust state. 3.3.1.1 The surface of the engine body and the cylinder liner, the main bearing hole and the threaded hole are not allowed to have any defects that cannot be removed by machining. 3.3.1.5 All water channels of the casting shall not be allowed to have any debris or other debris that may seriously affect the water flow. 3.3.2 Casting defects allowed in castings
3.3.2.1 The height of the cast and burnt mouth of the casting, except for specific parts, is allowed to be no more than 2mm without T surface and no more than 3mm with T surface
3.3.1.2 Except for the four provisions of 3.3.1.1~3.3.1.4, the defects specified in Table 3 are allowed on the surface of the casting, and the defects in the table are allowed, except for the surface
Unprocessed surface
Processed surface
Li Peng Zi Bie
Density!
1) The distribution range is not more than 3(0)mm.
2) No more than 4 defects per 1Umm length. 3! Special cases shall be agreed upon by both parties.
Incoming process
-Distance around hole
3.3.3 The air tightness of castings shall be able to withstand a water pressure test of not less than 40MPa without leakage. 3.3.4 The roughness of casting surface shall be checked by the supplier and the buyer jointly selected standard samples. 3.3.5 The inner cavity clarity of special parts shall be controlled by the inspection standards jointly agreed upon by the supplier and the buyer. The "
" mark on each process surface
3. 4 Repair of castings
JB/T 9742-1999
3.4.1 Any casting defects on the inner surface of the cylinder bore of the engine body or the surface matching the cylinder liner, the bottom surface of the cylinder head and the range contained by the cylinder die and other key parts are not allowed to be repaired.
3.4.2. The integrity of the sand inclusions, the tightness of the air holes and the shrinkage are not allowed to be filled. 3.4.3 In addition to the provisions of 3.4.1 and 3.4.2, the cylinder and the body of the machine body can be filled by using appropriate sample filling process. However, the parts after filling must meet the technical requirements of this standard. 3.4.4 It is allowed to use appropriate barrier fillers and paint filling processes to fill the castings, but the service life and tightness of the filled parts must be guaranteed.
3.5 Residual stress of the rotating parts
3. 5.1 The residual stress of the casting should be reduced to a level that can maintain the working life of the casting and the stability of the dimensional accuracy. 3.5.2 Different measures may be taken to eliminate or reduce residual stress [including annealing or non-annealing measures] to meet the requirements of 3.5.1. 4 Mechanical test
4.1 The tensile test shall be carried out in accordance with the provisions of 7945: 4.2 The test sample used for the tensile test can be selected according to 5.3. 5 Test sample
5 Preparation of single chain test bar
5.1.1 Single casting test shall be carried out in a dry sand mold or a sand mold with similar thermal conductivity. If the supply and demand parties agree, wet molds can also be used for vertical casting in the read-back mold. The free space of the test sample shall not be less than 50m, as shown in Figure 1. 5.1.2 The test bar must be poured with the same water-free flow as the wash casting. 5.! .3 The cooling time of the test piece in the mold should be no less than 30 minutes. 5.2 Attached cast test block
When using attached cast test blocks, they can be prepared according to Figure 2.
Figure 1 Single cast test block
Note: The size is determined by the length of the tensile test piece and the vibration device. Figure 2 Attached test block
5.3 Preparation of tensile test pieces
JB/T9742—1999
5.3.1 The tensile test pieces are divided into type A and type B according to JB/T7943, as shown in Figures 3 and 4. When doing tensile tests, the type of test piece can be determined by both parties.
5.3.2 The size of the test piece is listed in Table 4. The two sides of the test piece can be processed into a spiral shape or a columnar shape to meet the needs of the clamping device. 5.3.3 When taking tensile test pieces from a piece or attached test block with a thickness of less than 25 mm, T or C type can be added, as shown in Figure 5. For the parts with a total thickness less than [m, the test method, test type and size shall be determined by the supply and demand parties through negotiation. ) AI type
Figure 3A type test sample
a) B type
Figure 4B type reduction test sample
Small parallel zone length world
Test sample diameter 4
Reverse circle red radius R
Columnar wax part
Explosion-shaped clamping joint part
6 Inspection rules
6.1 Inspection responsibilities
JB Hall 9742—1999
Figure 4 [End]
4 Dimensions of test sample
Small diameter d
Longest zone!
Effective diameter t pitch d
Minimum length
(School area length shop)
Figure 5C Whole sample
Requirements, 1.1 The inspection of castings shall be carried out by the supplier's technical inspection department. 23
Additional tolerance
6.1.2 If the party has any doubts about the reliability of the supplier's inspection, it can reserve the right to conduct its own inspection: it can also require the supplier to conduct a modified inspection or to conduct another sample for damage or other special inspection, but it should be carried out according to the reasonableness of the reason and after consultation with the supplier. 6.2 Sampling frequency
6.2.1 Material inspection sampling frequency
6.2.1.1 The inspection batch is determined by the following situations: 1) When the same ingredients and the same brand of ash are continuously melted in a cupola, a 2-hour pouring period is considered as a batch: JE/L9742—1999
6) When smelting in continuous molten iron equipment (such as electric furnace), each furnace of molten iron is considered as a batch: 2) When the same brand of molten iron is used in one furnace for different treatments in a ladle or a holding furnace, the ladles treated in the same hour should also be considered as a batch:
d! Due to the differences in the melting process and control, the division of batches can also be adjusted appropriately. 6.2.1.2 At least 3 test bars are poured for each batch, and the test bars must be able to correctly represent the properties of the batch of molten iron. 6.2.1.3 The body hardness of castings shall be checked at least once per shift. If there are special requirements, they shall be carried out in accordance with the provisions of 3.1.4 and 3.1.5. The test method shall be carried out in accordance with the provisions of GB:T231.
6.2.2 Sampling frequency of dimension inspection in several directions
6.2.2.1 The dimensions of the relevant parts of castings shall be checked with templates or tools on a daily basis. The sampling frequency shall be not less than 2%. 6.2.2.2 The castings shall be checked for marking at least twice a month. The wall texture of the castings shall be checked with a thickness gauge or dissection at least once a month. 6.2.3 Frequency of appearance inspection
100% of the sintered castings shall be inspected for appearance. 6.3 Number of tests and validity
6.3.1 For each batch of test pieces, take one of them for tensile test. If the strength reaches the requirements specified in 3.1.1, the material of the batch of castings is qualified. If the test results do not meet the requirements, two more test pieces can be selected from the same batch of test pieces for repeated tests. 6.3.2 If the test results meet the requirements, the material of the batch of castings is still qualified. If one of the test results still does not meet the requirements, the condition of the batch of castings does not meet the standard requirements. 6.3.3 If the poor test results are not caused by the quality of the casting itself, but by the defects of the specimen, processing defects or improper assembly, the test is invalid and the test should be repeated according to 6.3.1 and 6.3.2. If there is no spare specimen, the original specimen can be tested. If the strength reaches the requirements specified in 3.1.2, the batch of castings is also qualified. 6.3.4 The test of special items shall be carried out by the supplier and the buyer in cooperation. Preparation before delivery
7.1 Coating
Castings shall be coated with a coating that meets the requirements of the ordering technical conditions, and the painted surface shall be kept clean. 7.2 Marking
Each qualified part shall be marked with the manufacturer, production date or batch number and inspection pass mark. 7.3 Certificate
All exported castings shall be accompanied by a certificate of quality issued by the inspection department, which shall indicate the following: a) Part drawing number and delivery quantity; b) Relevant data or date of inspection results;
! Manufacturer name, printing and delivery date. 7.4 Packaging and storage
For parts that need to be transported over long distances, they shall be reasonably packaged and stored according to commercial requirements or carrier requirements.1.1 The inspection of castings shall be carried out by the supplier's technical inspection department. 23. Add tolerance. 6.1.2 If the supplier has any doubts about the reliability of the supplier's inspection, it may reserve the right to conduct its own inspection: it may also require the supplier to conduct a modified inspection or a separate sample for damage or other special inspection, but it shall be carried out according to the reasonableness of the inspection and after consultation with the supplier. 6.2 Sampling frequency
6.2.1 Material inspection sampling frequency
6.2.1.1 The inspection batch is determined by the following situations: 1) When the same ingredients and the same brand of ash are continuously melted in a cupola, a 2-hour pouring period is considered as a batch: JE/L9742—1999
6) When smelting in continuous molten iron equipment (such as electric furnace), each furnace of molten iron is considered as a batch: 2) When the same brand of molten iron is used in one furnace for different treatments in a ladle or a holding furnace, the ladles treated in the same hour should also be considered as a batch:
d! Due to the differences in the melting process and control, the division of batches can also be adjusted appropriately. 6.2.1.2 At least 3 test bars are poured for each batch, and the test bars must be able to correctly represent the properties of the batch of molten iron. 6.2.1.3 The body hardness of castings shall be checked at least once per shift. If there are special requirements, they shall be carried out in accordance with the provisions of 3.1.4 and 3.1.5. The test method shall be carried out in accordance with the provisions of GB:T231.
6.2.2 Sampling frequency of dimension inspection in several directions
6.2.2.1 The dimensions of the relevant parts of castings shall be checked with templates or tools on a daily basis. The sampling frequency shall be not less than 2%. 6.2.2.2 The castings shall be checked for marking at least twice a month. The wall texture of the castings shall be checked with a thickness gauge or dissection at least once a month. 6.2.3 Frequency of appearance inspection
100% of the sintered castings shall be inspected for appearance. 6.3 Number of tests and validity
6.3.1 For each batch of test pieces, take one of them for tensile test. If the strength reaches the requirements specified in 3.1.1, the material of the batch of castings is qualified. If the test results do not meet the requirements, two more test pieces can be selected from the same batch of test pieces for repeated tests. 6.3.2 If the test results meet the requirements, the material of the batch of castings is still qualified. If one of the test results still does not meet the requirements, the condition of the batch of castings does not meet the standard requirements. 6.3.3 If the poor test results are not caused by the quality of the casting itself, but by the defects of the specimen, processing defects or improper assembly, the test is invalid and the test should be repeated according to 6.3.1 and 6.3.2. If there is no spare specimen, the original specimen can be tested. If the strength reaches the requirements specified in 3.1.2, the batch of castings is also qualified. 6.3.4 The test of special items shall be carried out by the supplier and the buyer in cooperation. Preparation before delivery
7.1 Coating
Castings shall be coated with a coating that meets the requirements of the ordering technical conditions, and the painted surface shall be kept clean. 7.2 Marking
Each qualified part shall be marked with the manufacturer, production date or batch number and inspection pass mark. 7.3 Certificate
All exported castings shall be accompanied by a certificate of quality issued by the inspection department, which shall indicate the following: a) Part drawing number and delivery quantity; b) Relevant data or date of inspection results;
! Manufacturer name, printing and delivery date. 7.4 Packaging and storage
For parts that need to be transported over long distances, they shall be reasonably packaged and stored according to commercial requirements or carrier requirements.1.1 The inspection of castings shall be carried out by the supplier's technical inspection department. 23. Add tolerance. 6.1.2 If the supplier has any doubts about the reliability of the supplier's inspection, it may reserve the right to conduct its own inspection: it may also require the supplier to conduct a modified inspection or a separate sample for damage or other special inspection, but it shall be carried out according to the reasonableness of the inspection and after consultation with the supplier. 6.2 Sampling frequency
6.2.1 Material inspection sampling frequency
6.2.1.1 The inspection batch is determined by the following situations: 1) When the same ingredients and the same brand of ash are continuously melted in a cupola, a 2-hour pouring period is considered as a batch: JE/L9742—1999
6) When smelting in continuous molten iron equipment (such as electric furnace), each furnace of molten iron is considered as a batch: 2) When the same brand of molten iron is used in one furnace for different treatments in a ladle or a holding furnace, the ladles treated in the same hour should also be considered as a batch:
d! Due to the differences in the melting process and control, the division of batches can also be adjusted appropriately. 6.2.1.2 At least 3 test bars are poured for each batch, and the test bars must be able to correctly represent the properties of the batch of molten iron. 6.2.1.3 The body hardness of castings shall be checked at least once per shift. If there are special requirements, they shall be carried out in accordance with the provisions of 3.1.4 and 3.1.5. The test method shall be carried out in accordance with the provisions of GB:T231.bzxZ.net
6.2.2 Sampling frequency of dimension inspection in several directions
6.2.2.1 The dimensions of the relevant parts of castings shall be checked with templates or tools on a daily basis. The sampling frequency shall be not less than 2%. 6.2.2.2 The castings shall be checked for marking at least twice a month. The wall texture of the castings shall be checked with a thickness gauge or dissection at least once a month. 6.2.3 Frequency of appearance inspection
100% of the sintered castings shall be inspected for appearance. 6.3 Number of tests and validity
6.3.1 For each batch of test pieces, take one of them for tensile test. If the strength reaches the requirements specified in 3.1.1, the material of the batch of castings is qualified. If the test results do not meet the requirements, two more test pieces can be selected from the same batch of test pieces for repeated tests. 6.3.2 If the test results meet the requirements, the material of the batch of castings is still qualified. If one of the test results still does not meet the requirements, the condition of the batch of castings does not meet the standard requirements. 6.3.3 If the poor test results are not caused by the quality of the casting itself, but by the defects of the specimen, processing defects or improper assembly, the test is invalid and the test should be repeated according to 6.3.1 and 6.3.2. If there is no spare specimen, the original specimen can be tested. If the strength reaches the requirements specified in 3.1.2, the batch of castings is also qualified. 6.3.4 The test of special items shall be carried out by the supplier and the buyer in cooperation. Preparation before delivery
7.1 Coating
Castings shall be coated with a coating that meets the requirements of the ordering technical conditions, and the painted surface shall be kept clean. 7.2 Marking
Each qualified part shall be marked with the manufacturer, production date or batch number and inspection pass mark. 7.3 Certificate
All exported castings shall be accompanied by a certificate of quality issued by the inspection department, which shall indicate the following: a) Part drawing number and delivery quantity; b) Relevant data or date of inspection results;
! Manufacturer name, printing and delivery date. 7.4 Packaging and storage
For parts that need to be transported over long distances, they shall be reasonably packaged and stored according to commercial requirements or carrier requirements.
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