JB/T 4328.4-1999 General technical requirements for forging of electrical equipment
Some standard content:
JB/T4328.4-1999
This standard is a revision of JB4328.4-86 "General Technical Conditions for Forging of Special Electric Equipment". In the revision, this standard adopts the former West German standard DIN7525, Part 1 "Machining allowance and allowable deviation of steel forgings, free forging discs", DIN7527, Part 2 "Machining allowance and allowable deviation of steel forgings, free forging discs with holes", DIN7527, Part 4 "Machining allowance and allowable deviation of steel forgings, free forging seamless cylinders", DIN7527, Part 6 "Machining allowance and allowable deviation of steel forgings, free forging bars", and refers to the former Soviet Union national standard OCT8479 "Technical requirements for carbon structural and alloy structural steel forgings", and refers to the West German industrial standard DIN7521 "Technical conditions for supply of steel forgings", British standard BS4114 and other foreign standards. This standard replaces JB4328.4-86 from the date of implementation. This standard is proposed and managed by Shenyang Electrician Special Equipment Research Institute. This standard is drafted by Shenyang Electrician Special Equipment Research Institute. The main drafter of this standard: Chen Jiashan.
This standard was first issued on December 1, 1986. This standard was revised for the first time. Shenyang Electrician Special Equipment Research Institute is entrusted with the interpretation of this standard. 78
Machinery Industry Standard of the People's Republic of China
General Technical Conditions for Forging of Electrician Special Equipment
Forginggeneral requirements for the electricianspecial equipment
JB/T4328.4—1999
Replaces JB4328.4—86
This standard specifies the requirements, test methods, inspection rules and markings for forging of free forging steel parts and die forging steel parts for electrician special equipment. This standard applies to free forging steel parts and die forging steel parts for electrician special equipment. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When the 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 versions of the following standards. GB/T222—1984
GB/T223.11981
GB/T226—1991
GB/T228—1987
GB/T 2291994
GB/T231—1984
JB/T4249.8—1986
JB/T42501986
3 Requirements
Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products Determination of carbon content in steel and alloys
Macrostructure and defect acid etching test method for steel (neqISO4969:1980) Metal tensile test method
Metal Charpy notch impact test method (eqvISO148:1983) Metal Brinell hardness test method
Machining allowance and tolerance of steel free forgings on hammer Black forgings Machining allowance and tolerance of steel die forgings on hammer 3.1 The steel grade of the steel ingot or steel bar used for forgings shall comply with the provisions of the product drawings. 3.2 The steel ingot or steel bar used for forgings shall have a certificate of conformity. When there is no certificate of conformity, the product shall be inspected before it leaves the factory and can only be used after it passes the inspection.
3.3 The surface of the steel ingot or steel shall not have defects such as cracks, folds, notches, etc., and the surface defects that can be removed shall be thoroughly removed. 3.4 The forging ratio of forgings is generally between 2:1 and 3:1. 3.5www.bzxz.net
The weight of free forging steel parts is generally less than 800kg. 3.6
The weight of die forging steel parts is generally less than 250kg, and the length (limit size) does not exceed 2500mm. The forging accuracy level of forgings shall be implemented in accordance with the provisions of the drawings or technical documents. If no provisions are made, the accuracy level is shown in the table! . Approved by the State Bureau of Machinery Industry on August 6, 1999-
Implemented on January 1, 2000
Free forging steel parts
Die forging steel parts
JB/T4328.4-1999
Note: Grade F is the standard for forging steel parts during hammer forging. Ordinary grade is suitable for general precision. Accuracy grade
Ordinary grade
During the forging process, the heating, initial forging temperature, final forging temperature and cooling process of the forging rough part shall be carried out in accordance with the process regulations, and technical records shall be made for important 3.8
forgings. Overburning is not allowed during the heating process, and the depth of the surface decarburization layer shall comply with the provisions of Table 2. Table 2
Stress state
Frequent and complex
Alternating stress
Complex alternating stress, large
torque or high-speed movement
Machinery surface
Non-machinery surface
Machinery surface
Non-machinery surface
Carbon layer depth
≤12Machining allowance
Small and medium parts
≤1/2Machining allowance||t t||Small and medium-sized parts
No specific provisions
Special parts
Application examples
Front axles, half axles, steering systems and
Forgings for brake systems
Crankshafts, connecting rods, universal joints
Forks, cross shafts
Gears, connectors, handles
Note: For forgings belonging to categories 1 and 2, the category of forgings shall be indicated in the drawings or relevant design documents. Forgings belonging to category 3 shall not be indicated. 3.10
Forgings shall not have defects such as interlayers, folds, cracks, forging marks, scars, slag inclusions, bubbles, white spots, etc. When the depth of these defects does not exceed 15% of the wall thickness and the defect area does not exceed 20% of the area, it is allowed to scrape clean and then weld. The mechanical properties after welding shall meet the mechanical properties of the parent material. When these defects do not exceed the minimum size specified by the part process, they are allowed to exist. 3.11
When there are dents on the forging surface due to the formation of iron oxide scale, the allowable depth of the surface defect is shown in Table 3. Table 3
Surface to be processed
Surface not to be processed
Depth not exceeding one-half Specified machining allowance Depth not exceeding one-third Maximum thickness tolerance 3.12
When the depth of surface defects of carbon steel and low alloy steel forgings exceeds the tolerance of machining, it is allowed to be removed along the inclined direction and then welded with the same material.
3.13After forging, annealing or tempering treatment should be carried out to ensure the specified mechanical properties. The specific heat treatment specifications shall be formulated by the user unit. However, if it falls into one of the following situations, heat treatment is not allowed. a) Small forgings that have been uniformly heated during the forging process: b) Forgings with a carbon content of less than 0.25%.
3.14The shape, size and tolerance of forgings shall comply with the requirements of forging drawings and process documents. 3.15 When hot-cutting free forgings, the bevel angle formed by the end should be less than or equal to 10°. If there is a test specimen connected to it, the connection size is generally 15~30mm (see Figure 1 and Figure 2). 80
JB/T4328.4-1999
3.16 The width of the arc expansion of the end of the drawn forgings due to the lack of head should be less than or equal to 0.15D, and the shoulder bevel angle formed by the clamp should be less than or equal to 15° (see Figure 3). 3.17 Machining allowance and limit deviation of free forged steel parts. Figure 3
≤15*
≤0. 15 D
3.17.1 The forging size of the disc should meet the following conditions: 0.1d,≤hz≤1.5dz. The machining allowance and limit deviation of the disc are shown in Figure 4, Table 4 and Table 5.
Discs are suitable for low alloy structural steel, carbon steel and carbon tool steel with a carbon content not exceeding 0.9% or a total alloy content not exceeding 4%. Z
di, h-forging dimensions; dz, hz forging dimensions Figure 4
JB/T4328.4-1999
059-005
05~00%
00%~09
091-001<
59~0b<
JB/T4328.4-1999
099~005<
005100
091-00
3.17.2 Free forging steel parts, discs with holes. JB/T4328.4-1999
3.17.2.1 The shape and size of the perforated disc shall meet the following conditions: 0.1dhd
40≤d≤0.3d, or 40≤d,≤0.25 (d, +hz) 3.17.2.2 The perforated disc is suitable for low alloy structural steel, carbon steel and carbon tool steel with a carbon content not exceeding 0.9% or a total alloy content not exceeding 4%.
3.17.2.3 The machining allowance and limit deviation of the disc with holes are shown in Figure 5, Table 6 and Table 7. h
da d ha
Zt, Z, Zy
Forging size
-Forging size
Machining allowance
JB/T4328.4-1999
09-005
005~00K
SiE~osz
002-091
JB/T4328.4-1999
099~00s<
005-00
002091
091~0 01<
001~9<
3.17.3 Free forging steel parts, seamless rings
JB/T4328.4—1999
3.17.3.1 The shape and size of seamless rings shall meet the following conditions: o.2(dd）)h,d
d≥50
d,>0.25（d+hz）
3.17.3.2 Seamless rings are suitable for low alloy structural steel, carbon steel and carbon tool steel with a carbon content not exceeding 0.9% or a total alloy content not exceeding 4%.
The machining allowance and limit deviation of seamless rings are shown in Figure 6, Table 8 and Table 9. 3.17.3.3
3.17:3.4 Additional provisions for thin-walled rings: The values of dj, d, and h, obtained from Table 8 must be multiplied by the coefficients given in the right half of the table and rounded to integers in millimeters.
d, d, h,
dg, da, h2
Forging size
Forging size
-Machining allowance
Z, Z\
JB/T4328.4-1999
091~001
001~9<
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