JB/T 4385.1-1999 General technical conditions for hammer free forgings
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JB/T 4385. 1.-. -1999
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Preface
This standard is a revision of JB4385-87 "General Technical Conditions for Hammer Free Forgings". Compared with JB4385--87, the main technical content of this standard has changed as follows: 1) A preface and citation standards have been added in accordance with relevant regulations. 2) The chapter numbers have been adjusted.
3) The specific requirement for the forging ratio is canceled and instead the forging is required to have sufficient deformation to ensure the quality of the forging. 4) "Mechanical properties" is renamed to "mechanical properties", and reference standards are added; "user" is renamed to "demand side", and "manufacturing unit" is renamed to "manufacturing" or "supplier".
5) About forgings The level is classified according to the provisions of GB/T12363---1990 "Functional Classification of Forgings". According to the new regulations, the original level V as important parts is changed to level 1 as important parts
6) About forging inspection. The relevant provisions have been modified according to the provisions of JB/T8421--1996 "General Rules for Inspection of Steel Self-Extruding Forgings"
This standard will replace JB4385-87 from the date of implementation. This standard is adopted by the National Forging Standardization. Proposed and managed by the Technical Committee. Drafting unit of this standard: First Design Institute of the Ministry of Machinery Industry. Main drafters of this standard: Lian Wu, Li Baoqian 277
Mechanical Industry Standards of the People's Republic of China| |tt||General specifications for open die forgings on hammerJB/T 4385. 1 --- 1999
replaces J3 4385--87
this The standard applies to general-purpose forgings (including tire mold forgings) free-forged on a hammer from ordinary carbon steel, high-quality carbon steel and alloy structural steel. Relevant special standards should be adopted for some special-purpose forgings and special requirements. ; If there is no special standard, this standard may be referred to, but the specific matters must be mutually agreed upon and signed by both parties. 2 Quoted standards
The provisions contained in the following standards constitute this standard by citation in this standard. When this standard is published, the versions shown are valid. All standards will be revised. Parties using this standard should explore the possibility of using the latest version of GB/T2221984 Steel Samples. Allowable deviations in chemical composition of methods and finished products GB/T223.1~223.77-1981~~1994 Methods for chemical analysis of steel and alloys GB/T 226--1991
Acid etching inspection method for low-magnification structures and defects of steel GB /T 228. 1987
Metal tensile testing method
GB/T 229.--1994
GB/T 231 -1984
GB/T 1814-- 1979
GI3/T 1979.---1980
GB/T 2971- -1982
GB/T 4236-- 1984
Metal Charpy notch impact test Methods
Metal Brinell Hardness Test Method
Steel Fracture Inspection Method
Low-magnification Structure Defect Rating Chart of Structural Steel
Fraction Inspection Method for Carbon Steel and Low Alloy Steel Sulfur print inspection method for steel
GB/T 10561-- 1989
GI3/T 12363--1990
GB/T 13298
---1991|| tt||GB/T 13299
1991
GB/T 14452.-- 1993
Microscopic evaluation method of non-metallic inclusions in steel Functional classification of forgings
Metal Microstructure inspection method
Microstructure evaluation method of steel
Metal bending mechanical properties test method
GB/T15826.1~~15826.9-1995 Chain steel free forging machinery Add. Margins and Tolerances JB/T 842] -: 1996
JB/T 8467--- 1996
Steel Free Forgings: General Inspection Rules
Ultrasonic Flaw Detection of Steel Forgings Methods
YB/T 51481993
Method for determination of average grain size of metals
3 technical elements
3.1 Ordering conditions
3.1.1 The purchaser should be in The consultation card or order contract provides the manufacturer with the necessary original data for forging production. These information are: a) Quantity and material of forgings:
: b) Forging drawings, rough machining drawings or parts drawings (if the forging drawings are drawn by the manufacturer, they must be approved by the purchaser); National Machinery Industry Bureau 1999 -06-24 Approved 278
2000 01-01 Implementation
c) Inspection procedures and test levels for forgings. JB/T4385.1—1999
3.1.2 Requirements beyond the provisions of this standard are recommended (such as special requirements for mechanical property testing, low-magnification structure, metal machinery, non-destructive testing, etc.). The buyer can contact us on the consultation card or This should be submitted to the manufacturer when placing an order, and will be determined through negotiation between both parties. 3.2 Steel for forgings
3.2.1 Forgings can be made directly from steel ingots, but the steel ingots should be killed steel, and the furnace number must be marked and accompanied by an inspection certificate. 3.2.2 Forgings can be forged from rolled materials or steel ingots Made of forged steel. These steels must have a factory certificate of conformity. 3.2.3 Steel ingots, steel chips and rolled products without certificates of conformity must be re-inspected according to relevant material standards and can only be used after being confirmed to be qualified. 3.2.4
The manufacturer must produce forgings according to the steel number specified in the buyer's drawings. If substitution is required, the buyer's consent must be obtained and written documentation must be obtained. 3.2.5 The chemical composition of the steel used for forgings shall be sampled and analyzed. The results are based on the results, and their values ??are in accordance with the provisions of the current national standards or industry standards. Steel grades other than national standards and industry standards are determined by negotiation between the supply and demand parties. 3.2.6 When the purchaser requires verification analysis of the chemical composition of forgings, it shall be carried out in accordance with the provisions of GB/T222 and GB/T223.1~223.77.
3.2.7 If the purchaser requires sampling for verification and analysis of the chemical composition of forgings at locations other than those specified in the standard. It should be stated on the ordering contract, and the allowable deviation used should be determined through negotiation between the supplier and the buyer. 3.3 Technical Requirements
3.3.1 When forging forgings with steel ingots or steel chips, all surface defects that affect the quality of the forgings must be removed before forging. There must be sufficient resection at both ends of the steel ingot.
3.3.2 Forgings should have sufficient deformation to ensure that they meet the quality requirements of forgings. 3.3.3 The deformation of steel should be carried out on equipment with sufficient energy to ensure forging penetration. 3.3.4 During the production process of forgings, the heating of roughness, the control of initial forging and final forging temperatures, and the cooling of forgings should be carried out in accordance with the relevant specifications of the manufacturer. Technical records should be kept for important forgings. 3.3.5 Forgings should generally be kept in Delivery after the first heat treatment, heat treatment specifications shall be formulated by the manufacturer. If the demander has special requirements, they shall be noted in the contract after mutual agreement.
3.3.6 When the bending and warping deformation of the forgings after heat treatment exceeds the tolerance range, it should be corrected by the manufacturer. After correction in the cold or hot state, the forgings belonging to Level 1 and Level 1 tests should be Tempering to eliminate stress; whether forgings belonging to Class II, V, and V tests are tempered is decided by the manufacturer. Forgings after correction or tempering should ensure their mechanical properties (see Table 1 for test classification of forgings). 3.3.7 The mechanical properties of commonly used steel grade forgings should comply with the requirements of relevant standards. If there are special requirements for mechanical properties, they must be determined through negotiation between supply and demand.
3.3.8 Test classification of forgings
According to the design requirements, working characteristics and uses of various forgings, the purchaser can determine the category of forgings in accordance with the provisions of GB/T12363; the inspection level of forgings is in accordance with JIB3 /T8421 is carried out and is divided into levels I, III, IV and V. Each level specifies the test items and the number of forgings to be inspected, see Table 1.
Table 1 Test items and inspection quantities for forgings level table Forgings
Level
Day
Chemical composition
Each heat number
per··heat number
every heat number
every-heat number
hard
100%
100%
100%
5% of each batch,
not less than 5 pieces
test items and inspection quantity
stretch (or a.2)
100%
2% for each batch, but not less than 2 pieces
Chong (A)
25% for each batch, but ||tt| |No more than 2 pieces
Batch conditions
Inspection of completed parts
Same furnace number and manufacturer
Heat treatment heat
Same steel number, same
Heat treatment heats
Shangganghao.com
Heat treatment heats
279
Forgings
Level chemical composition||tt| |Each heat number
Note
Hardness
JB/T4385.1--1999
Table 1 (End)
Test items and inspection quantity | |tt | |tt||2 After calculating the inspection quantity by percentage, the remainder less than 1 piece shall be counted as 1 piece. 31. The hardness value of Grade I forgings shall not be used as the basis for acceptance. 3.3.9 The test level of the forgings shall be specified in the drawing and ordering contract. Marking example: Level II test-JB/T8421 (additional test items and technical requirements). If the test level of the forging is not indicated on the drawing or order contract, the manufacturer shall treat the forging as Level √ 3.3.10. The shape and size of the forgings should comply with the provisions of the forging drawings
Same as steel number
3.3.11 The machining allowance, tolerance and remaining block specified on the forging drawings shall be in accordance with GB/T15826. .1~15826.9 shall be implemented. 3.3.12 If there are defects such as cracks, folds, forging wounds, laminations, scars, and slag inclusions on the surface of the forging, the following provisions shall be followed: a) The surface of the forging that needs to be machined shall be inspected and confirmed. When the depth of the defect can ensure that more than 50% of the machining allowance is left, it is not allowed to be removed, but it must be agreed by the purchaser;
b) The maximum depth of the forging surface that will no longer be machined shall not exceed that point. If the depth of the surface defect of the forging exceeds the machining allowance, if repair welding is required, the consent of the purchaser must be obtained. After the defects are completely removed, repair welding is carried out according to appropriate repair welding procedures. The quality of the repair welding must meet the requirements of the purchaser for the forgings. 3.3.13 Whether the surface of forgings needs to be cleaned and the cleaning method shall be agreed upon by both parties when placing orders. 3.3.14 The manufacturer should ensure that there are no white spots on the forgings. When white spots are found on a forging, the entire batch of forgings from the same furnace heat treatment as the forging should be self-inspected one by one: 3.4 Test methods and acceptance rules
3.4.1 Test methods
a) The inspection of finished forgings shall be carried out in accordance with the provisions of JB/T8421. b) The chemical composition analysis of steel for forgings shall be carried out in accordance with the provisions of 3.2.5~3.2.7. c) Mechanical property test
·-The tensile test method shall be carried out according to the provisions of GB/T228: the impact test method shall be carried out according to the provisions of GB/T229; the hardness test method shall be carried out according to the provisions of GB/T231. d) If there are cracks, non-metallic inclusions and other defects on the cross-section of the specimen used for the tensile test of forgings, the forgings should be inspected at low magnification and ultrasonic flaw detection. During ultrasonic flaw detection, the scope, depth, flaw detection method and acceptance conditions of the flaw detection part should be clearly defined. The test method refers to the regulations of 113/18467.
C) White spot inspection can be carried out on specially cut test pieces or on the forging body using any method that can ensure the reliability of the inspection.
1) Other test items
In addition to the above test items, if the purchaser requires the following items to be tested, it should be negotiated with the manufacturer when ordering. Any such agreement should include the details of the test procedures.
When inspecting the following items, each inspection should clearly specify the sampling location and acceptance level. The inspection methods are as follows: the low-magnification tissue picking method and evaluation shall be carried out in accordance with the provisions of GB/T226 and GB/T1979; the fracture inspection method and The assessment shall be carried out in accordance with the provisions of GB/T1811 and G13/T2971; - the sulfur print inspection method shall be carried out in accordance with the provisions of GB/T4236; 280
JB/T 4385.----1999
The microstructure inspection method and evaluation shall be carried out in accordance with the provisions of GB/T13298 and GB/T13299: - The grain size determination method shall be carried out in accordance with the provisions of YB/T5148; the assessment method of non-metallic inclusions shall be carried out in accordance with the provisions of GB/T10561. g) Sampling position, sampling quantity and sample preparation. The position of the test block on the forging is determined according to the requirements of the drawing. If the drawing does not indicate the requirements, it can be decided by the manufacturer, but it must be guaranteed to represent the mechanical properties of the forgings. When the purchaser requires the storage of re-test blocks, the storage location of the test blocks shall be determined according to the agreement. When it is inconvenient to retain the test block in the forging, the forging can be destroyed for sampling. In this case, the manufacturer should increase the number of forgings used for testing. Other special circumstances shall be specifically negotiated between the manufacturer and the user.
—1~ The sampling position shall be implemented according to the provisions of JB/I8421. The cutting direction of a sample shall be determined according to the requirements of the drawing, if the drawing does not indicate the requirements. Can be chosen by the manufacturer (longitudinal, transverse or tangential).
The sampling quantity can be 1 tensile specimen and 2 impact specimens cut from each test block. The purchaser may also increase the number of test specimens based on the usage conditions of the forgings, but this should be clearly stipulated in the contract or drawing. The cut specimens shall not undergo any heat treatment that affects the mechanical properties. h) Retest
If the performance value of a certain sample fails to meet the specified requirements due to test equipment failure, incorrect sample preparation, or scratches unrelated to the material, the test will be discarded and may Re-sample the sample at an adjacent position in the forging for testing. During a tensile test, if the specimen breaks outside the gauge length or beyond 1/2 of the distance from the center of the gauge length to the gauge length point, and the test results do not meet the specified requirements, the specimen will be invalid and can be used. Re-sample the adjacent position of the sample in the forging for testing. If the sample fails to meet the specified requirements due to reasons other than white spots or cracks in the forging, the forging may not be reheated and retested by taking double samples adjacent to the sample. Both samples shall be Meeting the stipulated requirements: If the strength performance index of the forging is high, but the plasticity and toughness indexes fail to meet the stipulated requirements, the forging can be supplemented with tempering, and the number of supplementary tempering is not limited. After tempering, the test shall be carried out according to the original regulations. If the mechanical property test results of the forgings fail to meet the specified requirements, the manufacturer can reheat the forgings and conduct tests according to the original regulations
. Without permission from the purchaser, the number of reheat treatments shall not exceed 2 times. 3.4.2 Acceptance rules
a) The inspection and acceptance of finished forgings shall be carried out by the technical inspection department of the manufacturer. b) In addition to all visual inspections, forgings must also be tested according to the test items specified in the test level to which they belong and the test items specified in the contract. When necessary, the purchaser can conduct re-inspection. C) During the acceptance process, the purchaser can send personnel to conduct acceptance verification, and the manufacturer should provide convenient conditions for this. However, the purchaser's acceptance personnel shall not hinder the normal production and acceptance procedures of the manufacturer. d) When the manufacturer lacks test conditions, it is responsible for entrusting an appropriate unit to conduct the test. If the test is performed by the purchaser, the manufacturer can conduct re-inspection if necessary.
4 Marks and Quality Certificates
4.1 Marks
4.1.1 Forgings that pass the inspection should be marked. Contents of the mark: manufacturer’s logo, drawing number, work order number or contract number, steel number, furnace number (only marked on forgings for Level 1 and I tests), forging number. If the purchaser has special requirements for the mark, press Enforcing Contracts. If the mark is not worn, the buyer has the right to reject it.
4.1.2 Large and medium-sized forgings should be marked on the location specified in the drawing or process. If there is no provision, the location can be determined by the manufacturer. 4.1.3 Small batch forgings can be marked in batches. The hanging tag can be made of a thin aluminum plate or a thin steel plate, with the logo printed on it or written with paint. Www.bzxZ.net
4.1.4 For packed forgings, the content of the mark can be marked on the packaging box or printed on a label that can be firmly attached to the packaging box. 281
2 Quality Certificate
4.2
The content of the quality certificate should include:
a) Manufacturing name (or code));
b) Contract number;
c) Drawing number, forging name, forging number or serial number; d) Steel number;
JB/T 4385.1-1999
e) Melting furnace number ( Forgings for level I and II tests), forgings for level I testing still need to have heat treatment furnace number; f) heat treatment status;
g) main dimensions of forgings;
h) batch number and quantity of forgings ;
i) Inspection items and results;
i) Inspection conclusion:
k) The imprint of the technical inspection department and the signature of the inspection personnel. 282
1-1999
e) Melting furnace number (forgings for level I and II tests), forgings for level I testing still need to have heat treatment heat number; f) Heat treatment status;
g) Main appearance of forgings Dimensions;
h) Batch number and quantity of forgings;
i) Inspection items and results;
i) Inspection conclusion:
k) Imprint of the technical inspection department and Signature and seal of the inspector. 282
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