JB/T 9746.2-1999 This standard is a revision of ZB U48 001-89 "Technical Conditions for Gray Iron Castings for Marine Gearboxes". During the revision, only editorial modifications were made in accordance with relevant regulations, and the main technical content remained unchanged. This standard specifies the material, dimensional tolerance, machining allowance, weight deviation, allowable range of casting defects, and corresponding test methods and inspection rules for gray iron castings for marine gearboxes. This standard is applicable to gray iron castings for marine gearboxes cast by sand molds, and gray iron castings cast by other methods can also be used as a reference. This standard was first issued in 1989. JB/T 9746.2-1999 Technical Conditions for Gray Iron Castings for Marine Gearboxes JB/T9746.2-1999 Standard download decompression password: www.bzxz.net

ICS27.020
Machinery Industry Standard of the People's Republic of China
JB9746.21 Technical Conditions for Gray Castings for Marine Gearboxes Specificatious1999-09-17 Issued
National Bureau of Machinery Industry
2000-01-01 Implementation
R·T 974.1—1999
The small standard is for ZBU48001—9 gearboxes or other iron parts, technical conditions, repair time, maintenance modification to the original pool, ten technical changes are required from the date of implementation of this standard, replace ZDU48001—89, this standard is proposed and implemented by the National Internal Combustion Engine Standardization Technical Committee. The drafting unit of this standard is Shanghai Internal Combustion Engine Research Institute, Hangzhou Qianxun Gearbox Group Co., Ltd. The main drafters of this standard are Shou Shaolu, Shao Huaxing, and Zhen Jian. This standard was issued for the first time in 199.
1 Specification
Machinery Industry Standard of the People's Republic of China
Gray iron castings for marine gearboxes
Technical conditions
Gray iron castings for marine gearboxesSpecificatlonsHE9746.2—1999
14001-89
This standard specifies the material, dimensional tolerance, mechanical tolerance, tolerance, allowable range of defects, and test methods and inspection rules for gray iron castings for marine gearboxes. This standard is applicable to gray iron castings for marine gearboxes made of sand molds (hereinafter referred to as castings). Iron castings cast by other methods can also be used.
1 Referenced standards
The following standards contain the current provisions, which constitute the provisions of this standard through reference in the small standards. When the standard is published, the version shown is valid. All standards are subject to revision. The party using non-standard standards should explore the possibility of using the latest version of the following standards GB/T223.1~223.5—1981~1997 Analysis methods for steel and alloys GB/T23J19B4
GB/T2828—1987
GB/T 6060.J1997
GB/ 6414186
GB/T7216—1987
GE:T94391988
JB/T79451999
3 Technical requirements
3.1 Test method for Brinell hardness of cast iron
Test procedure and sampling table for batch inspection (applicable to continuous batch inspection) Comparison of roughness of cast surfaces
Dimensional tolerance of castings
Gray iron metallography
Gray iron castings
Test method for mechanical properties of gray cast iron
3.1.1 The grade of cast iron shall not be lower than HT150. The selection of grades shall comply with the provisions of GB/T9439. 3.1.2 The mechanical properties of the parts are generally based on the mechanical properties of the single chain test. If it is necessary to use the attached casting test or take samples from the part itself, the supplier and the buyer shall negotiate and agree, and note the following in the production sample or relevant technical documents: a) The position, shape and size of the test bar (type?); b) The sampling position, shape and size of the body sample. The mechanical properties of the single casting test, the test sample (block) and the casting at different locations shall comply with the provisions of GB/T9439. 3.1.3 The chemical composition, metallographic structure and hardness of the casting shall not be used as the basis for acceptance. If there is a special requirement for this, the sampling test position and the performance indicators to be mentioned shall be clearly stated in the product drawings or relevant technical documents. The organization of the chain shall conform to the provisions of GB/T7216: the hardness can be selected according to Appendix A of GB9439-198B, and from various hardness grades. Approved by Beijing Machinery Industry Bureau on September 17, 1999 and implemented on January 1, 2000. 3.2 Dimensional tolerances of chain parts: JH/T 9746.2-1999 3.2.1 Dimensional tolerances of chain parts shall conform to the provisions of GB/6414-1986: Select one of the Table A1 or Table A2 of this standard and mark it on the product drawings or relevant technical documents. The overall and rib thickness tolerances can be reduced by selecting and marking. 3.1.2 Pin type (box) values ​​shall be selected and marked according to the provisions of GB/T 414. If necessary, they can also be agreed upon by the supply and demand parties. The staggered type (box) values ​​must be included in the casting size tolerance values. 3.3 The machining margin and draft angle of the castings shall be selected according to the relevant standards, or determined by negotiation between the two parties. www.bzxz.net
3.4 ​​The shape deviation of the casting
3.4.1 The bending deformation of the casting shall be measured according to the maximum size of the casting. 3.4.2 The maximum allowable deformation of the casting on the non-reinforced surface shall be determined by the supplier; the allowable deformation of the casting on the surface shall ensure that the added surface has not less than 10% of the planned machining margin. 3.5 The deviation of the casting for single use
1.5.1 The inspection and acceptance basis of the production process: when the purchaser has requirements for this, it can also be used as the acceptance record, and the maximum allowable deviation of the casting shall be specified in Table 1.
piece quantity
>[00-500
sk unn
light sensitivity
ratio, large cow production of sharp parts
calculation: the table only stipulates the upper shrinkage of the parts, one is the lower shrinkage of the parts and the limit, %
single piece, small cow production; sharp parts
.5.2 Rust parts single book can be used to calculate its value or from a batch of tai grid chain parts from the box to extract the measured average value of the East casting density: HT150-HT2007.20kg/dm: HT250-HT5m7.35kg/dm
3.6 Casting surface quality
3.6.1 Special parts surface is not allowed to have mold age, core sand, sticky sand, material, burr. 3.1 The allowable range of the surface residue of the casting shall comply with the provisions of Table 2. Table 2
Where the root is lower than or lower than the value of the surface section, it shall not exceed 1.5mm, but it shall be handled as necessary! ! On the surface of the casting, the root is lower than the surface of the casting by 2/3 of the measurement. After the measurement, it is allowed to be no higher than the specified surface by 15mm. 3.6.3 The surface of the casting is allowed to have defects that are not like those in the repair: JB/T9746.2-1999
a) On the non-exposed surface of the casting, the defects specified in Table 3 are allowed. The parts that are not allowed to exist should be indicated in the production drawings or relevant technical documents.
b) The casting is allowed to have defects on the surface of the casting without repair. The maximum size does not exceed this mm, and the depth does not exceed 2mm. There are no more than "one of the above defects within the range of mm.) The casting is allowed to have defects within 100% of the specified surface. d) Non-important parts or non-important parts of parts are allowed to exist after repair. The size is less than @3rm, the distance from the edge is not less than 5mm, the depth is less than 1.5mm, and the total number of defects on each surface is not more than 3. For the evaluation position where defects are not allowed, it should be indicated in the product drawing or the technical document. :
Transmission force
>-0.03-0.55
Medicine category
The minimum defect size
The air hole, shrinkage, bulge, and sand fast defect depth
Less than 1/4 of the whole cover
where the fast sink is located, the maximum does not exceed 2.5
Less than 1/4 of the wall thickness
where the fast sink is located. The maximum does not exceed 3
Less than 14 of the wall thickness
where the defect is located. Avoid the largest defect not more than 4
between the top of the defect
the high side of the defect
the distance between the defect and the high side
not less than 10
the distance between the fast sinking
not less than 20
Note: Class I refers to the inspection castings and the quality parts of the castings: Class II refers to the non-important parts and the non-important parts of the castings. 3.6.4 After the sand inclusion defect is corrected, the wall thickness should be within the size tolerance range. 3.6.5 The same section of the inner and outer walls of the parts should be corrected. 3.6.6 Small parts are allowed to have cracks and depressions. 3.6.7 Special parts are allowed to have any depressions that affect the precision of the positioning surface. The number of depressions that affect the precision of the positioning surface is not allowed ...6. The key parts of the self-linking parts (such as the parts bearing the push knife) are not allowed to shrink. The parts that are allowed to have slight deformation should be indicated in the product drawings or relevant technical documents.
3.6.9 No connection defects are allowed in the corresponding holes. 3. The surface keyness R value of the parts such as 10 should comply with the provisions of GD/T6060.1, and one of the levels of 12.5, 25, and 50 should be selected and marked on the product drawings.
3.7 Casting defect repair
3.1 In the parts without external exposure, the defects that do not exceed the provisions of 1.6.Fb, but meet the provisions of Table 3, shall be repaired by appropriate methods.
3.7.2 Defects and parts that are not allowed to be welded: a) Defects: scattered sand inclusions, shrinkage, etc.; b) Parts: key pins and roughened surfaces, friction surfaces and parts subject to thrust. 3.2.3 For important castings determined by the ship inspection department, quick welding repairs shall be carried out, and the consent of the ship inspection department shall be obtained. 3.8 Heat treatment of castings
JBT9746.2—1999
Important parts shall be artificially aged and indicated in product drawings or relevant technical documents. 4 Inspection methods
4.1 Preparation of test pieces (blocks) and test specimens
4.1.1 Preparation of single cast test specimens and attached cast test specimens (blocks) The test shall be in accordance with the provisions of GB/T9439, and other types of tests agreed by the inspection and screening department may also be used.
4.1.2 The tensile test shall be in accordance with the A type in JT7945. 4.1.3 The test frame (block) and the test specimen shall be clearly marked so that the castings they represent can be identified. 4.2 The tensile test shall be in accordance with the provisions of JB/T7945. 4.3 The tensile test shall be in accordance with the provisions of Appendix A of GB/T94391988 and GB/T231. 4.4 Chemical analysis shall be in accordance with the provisions of GB/T223.1-223.5. 4.5 Metallographic inspection of castings shall be in accordance with the provisions of GB/T7216. 4.6 The casting surface roughness inspection of castings shall comply with GB/TG 0G0.F regulations. Use the corresponding comparison sample blocks to compare the surface torsion.
5 Inspection rules
51 The manufacturing quality inspection department shall inspect the mechanical properties, geometric shape, size and surface defects of the parts based on the product samples or relevant technical documents. The purchaser has the right to conduct random inspection or re-inspection of the parts. 5.2 The appearance quality of the castings shall be 100% inspected. 5.3 The geometric shape and size of the castings shall be inspected 100% of the time except for the first piece of each production. The castings produced in continuous batches can be inspected. The quantity and method of random inspection shall be in accordance with the provisions of GB/2828. 5.4 For certain important castings determined by the ship inspection department, the surveyor shall inspect and confirm 5.5 Other inspection rules shall comply with the provisions of GB/T9439. 6. Marks and certificates of conformity
6.1 Castings that have passed the inspection shall be accompanied by the mark of the quality inspection department of the manufacturer. 6.2 The parts to be inspected shall be accompanied by a certificate of conformity before leaving the factory, and shall indicate:) Name or code of the required part:
6) Name of the required part: drawing number and quantity to be delivered; e) Casting brand (important castings shall indicate the furnace number, package number, and sequence number); d) Chemical forming, mechanical properties and results; 3) Other technical content descriptions (such as heat treatment methods, repair methods, etc.) 6.3 For castings that are required to undergo ship inspection, a certificate of conformity shall also be attached.
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