JB/T 4328.7-1999 General technical conditions for heat treatment of electrical equipment
Some standard content:
JB/T4328.7-1999
This standard is a revision of JB4328.786 "General Technical Conditions for Heat Treatment of Special Electrical Equipment". This standard was proposed and managed by Shenyang Special Electrical Equipment Research Institute. This standard was drafted by Shenyang Special Electrical Equipment Research Institute and Shenyang Electric Machinery Co., Ltd. The main drafters of this standard are Cui Zhaozhi and Chen Jiashan. This standard was first issued on December 1, 1986, and this standard was revised for the first time. Shenyang Special Electrical Equipment Research Institute is entrusted with the interpretation of this standard. 122
1 Scope
Machinery Industry Standard of the People's Republic of China
General Technical Conditions for Heat Treatment of Special Electrician Equipment
Heat Treatmentgeneral requirementsfor the electrician special equipmentJB/T4328.7-1999
Replaces JB4328.7-—86
This standard specifies the requirements, test methods, inspection rules, marking and certificates for heat treatment of parts of special electrician equipment products. This standard applies to heat treatment of parts of special electrician equipment products. Where no requirements are made in product drawings or design documents, they shall comply with the provisions of this standard. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T224-1987
GB/T225—1988
GB/T230—1991
GB/T231—1984
GB/T1818-—1994
GB/T1979—1980
GB/T 4340--1984||t t||GB/T 105611989
YB/T5148—1993
3 Types and selection
3.1 Types of heat treatment
Method for determining the depth of decarburized layer of steel
Method for end fire test of steel permeability (eqvISO642-1979)Method for testing Rockwell hardness of metal (neqISO6508:1986)Method for testing Brinell hardness of metal
Method for testing surface Rockwell hardness of metal (neqISO1024:1989)Rating diagram of macrostructure defects of structural steel
Method for testing Vickers hardness of metal
Microscopic evaluation method of non-metallic inclusions in steel
Method for determining grain size of steel
3.1.1 General heat treatment includes: annealing, normalizing, quenching and tempering, tempering, induction heating surface hardening, flame quenching, tempering, artificial aging, etc.
3.1.2 Chemical heat treatment includes: carburizing, nitriding, carbonitriding, metallization, etc. 3.2 Scope of application of heat treatment process
3.2.1 Annealing treatment: Applicable to various alloy steels and tool steels, to eliminate their organizational defects and stress, and reduce hardness. 3.2.2 Normalizing treatment: Applicable to various medium carbon steels, medium carbon alloy steels and tool steels, to refine their grains and eliminate network carbides. 3.2.3 Quenching treatment: Applicable to all medium carbon steels, high carbon steels, and various alloy steels to improve hardness, wear resistance, strength, toughness and obtain certain physical and chemical properties.
Approved by the State Machinery Industry Bureau on August 6, 1999 and implemented on January 1, 2000
JB/T4328.7-1999
3.2.4 Tempering treatment: Applicable to all parts after annealing. Achieve its mechanical, physical and chemical properties. 3.3 Heat treatment selection for various parts
3.3.1 Shaft parts: Depending on their importance, they can be treated with processes such as no heat treatment, normalizing, quenching and tempering, or quenching and tempering plus surface rate tempering. 3.3.2 Wheel parts: Depending on their importance, they can be treated with processes such as no heat treatment, normalizing, quenching and tempering, or quenching and tempering plus surface rate tempering. Wheel precision parts or precision pairs can be treated with processes such as stabilization aging. 3.3.3 Fork parts: Depending on their importance, they can be treated with processes such as no heat treatment, normalizing, quenching and tempering, quenching, or local rate tempering. 3.3.4 Box parts: Whether weldments or castings, annealing, artificial aging, etc. should be used. 4 Requirements
4.1 Requirements before heat treatment of parts
4.1.1 The material of the parts must meet the requirements of the drawings and process documents. 4.1.2 The geometric shape, size, process allowance, surface roughness, etc. of parts shall comply with the requirements of drawings, processes and relevant standards. 4.1.3 Before heat treatment of certain parts, necessary organizational preparations shall be made. a) Normalizing or tempering treatment before induction quenching; b) Spheroidizing annealing treatment before quenching of tool steel parts, etc. 4.2 Requirements for parts after heat treatment
4.2.1 Annealed and normalized parts
The hardness of common steel after annealing and normalizing shall comply with the provisions of Table 1 and Table 2. Table 1: Hardness value of steel after annealing
T7, T8A
T10, T10A
≤197
ZG35Mn
T12, T12A
40MnVB
5CrMnMo
SCrNiMo
≤241
（GCr15SiMn）
197~207
（179~217）
3Cr2W8
（38Cr MoAlA）
（207-241）
W18Cr4V
Table 2 Hardness value of steel after normalizing
16Mn20Cr
20CrMnMa
≤197
20CrMnTi
207~241
30CrMnTi
143~197
170-229
The deformation of parts after annealing and normalizing should be less than 1/3 of its processing allowance (diameter or thickness). The oxidation and decarburization layers of parts after annealing and normalizing treatment should not exceed 1/3 of the machining allowance (diameter or thickness).4.2.2 Quenched and tempered parts
4.2.2.1 The hardness of the parts after quenching and tempering treatment before tempering: a) The diameter is greater than or equal to 50mm, and the hardness is not less than HRC35:124
60Si2Mn
≤187
≤269
JB/T4328.7-1999
b) The diameter is less than 50mm, and the hardness is not less than HRC45.4.2.3 Quenched parts
4.2.3.1 After quenching, there should be no defects such as cracks, burning, bruises and severe decarburization. 4.2.3.2 After quenching, the hardness value of the parts before tempering should not be lower than the middle limit of the hardness value required by the drawing. The hardness of the parts after tempering should meet the requirements of the drawing.
4.2.3.3 The deformation of parts after quenching and tempering is stipulated as follows: a) Flatness deviation of flat parts should not be greater than 2/3 of the single-sided allowance; b) The axis straightness of shaft parts (carburized and quenched parts) should be less than 1/3 of the allowance; c) Each side of sleeve parts should ensure sufficient allowance. 4.2.3.4 The depth of the hardened layer should meet the requirements of the drawings and process documents. If there is no requirement, the surface hardness shall prevail. 4.2.3.5 After quenching and tempering of parts, the surface decarburization layer should be less than 1/3 of the single-sided machining allowance. Induction Heating Surface Hardening Parts
Parts should not have oxide scale, scratches and sharp corners before quenching. Parts should be normalized or quenched and tempered before quenching. The deformation of parts after quenching should refer to the provisions of 4.2.3.3. The depth of the hardened layer should be based on the semi-martensite area. The depth is shown in Table 3. Table 3
Part type
Layer depth
Heating method
Gear
After quenching and tempering, the allowable width of soft zone and rate hard zone is shown in Table 4. 4.2.4.5
Part category
Allowable width of soft zone and unhardened zone
Tempering length deviation±3mm
Unhardened zone at step
Special-shaped parts and inner holes
Part category
With keyway
With hole and
With empty knife grid
Spline shaft
Step shaft and
Flange
JB/T4328.71999
Table 4 (continued)
Allowed width of soft zone and unhardened area
If there is no chamfer at both ends of the bottom, the two ends are allowed
a3mm soft zone
The distance between the unhardened area and the hole or palm is a3mm
A≤5mm soft zone is allowed at the empty knife groove. When high-frequency floating fire is allowed. The hardness of the groove bottom is allowed to be lower than the top by HRC5
It cannot be burned along the outer circle again. When continuous quenching is used, a soft zone of ≤30mm is allowed at the junction of the tempering. When quenching on the side, a non-hardened zone within a circumference of 0.75mm near the outside is allowed. Part category. Right angle two surfaces (including related surfaces). External angle. Part with hole. Flat surface with groove. Right angle two surfaces. JB/T4328.71999. Table 4 (continued). Allowed width of soft zone and non-hardened zone. Allowed to have a tempered soft zone of ≤8mm on one surface or allow one side to be non-hardened 5mm from the edge. Allowed to have a non-hardened zone of ≤8mm from both sides of the groove. Allowed to have a non-hardened zone of 5mm in depth. Allowed to have a non-hardened zone of 5mm from the bottom of the groove. Hard zone,
The hardened layer is allowed to be deeper at the sharp corners
The edge of the hole is a>6mm from the surface of the hardened zone.
The hole part is allowed to be not hardened
When the width of the narrow strip is a≤3mm, it is allowed not to be hardened
When high frequency or flame quenching is used, the intersection angle is allowed
a≤3mm not hardened, and there must be a blank knife or rounded corner at the intersection
Part category
Sleeve type
JB/T4328.71999
Table 4 (end)
Permitted width of soft zone and unhardened zone
Inner hole hardened zone is ≤200mm away from the end face.
Permitted soft zone with a≤10mm
Inner surface with inner diameter d<200mm, if the height is ≤350mm, it is allowed to have a
soft zone with a≤8mm around. If there is a groove inside. It is allowed that the fine part is not hardened. 4.2.4.6 Distribution of gear hardening layer is shown in Figure 1. Figure
200~400
Non-rate hardening
For non-carburized gears with a modulus not greater than 4, the tooth hardening layer is shown in Figure 1a, or full tooth hardening is allowed as shown in Figure 1b, and the tooth bottom surface has a hardening layer of not less than 0.5mm; for gears with a modulus greater than 4, the tooth surface should have a hardening area of not less than 2/3 of the tooth height as shown in Figure 1c. Figure 1
4.2.5 Flame quenching parts
Parts are not allowed to be bumped before flame quenching, and oxide scale and burrs should be removed to keep the surface of the workpiece clean. After flame quenching and before tempering, the hardness value of the parts shall not be lower than the middle limit of the hardness required by the drawing. 4.2.5.2
The deformation of the parts after quenching shall comply with the provisions of Article 4.2.3.3. The depth of the hardened layer of the parts after quenching is generally not less than i.5mm, and the hardened area should meet the following requirements; 4.2.5.42
a) When the gear module is greater than or equal to 8, the hardened area is not less than three-quarters of the tooth height; b) When the gear module is less than 8, the hardened area is not less than seven-eighths of the tooth height; c) For shaft parts, the limit deviation value of the quenched hardened layer length is ±5mm. 4.2.5.5 During quenching, soft bands are generally not allowed. Special parts are allowed to have some soft bands with a width of no more than 12mm, and their hardness value should not be lower than the Rockwell hardness value of 15 measured by the C scale with the lower limit of the hardness value specified on the drawing. 4.2.6 Carburized parts
The depth of the carburized layer of the parts shall meet the requirements of Table 5. 4.2.6.1
Nominal carburizing depth
Depth range
1.10~1.50
1.50~1.90
JB/T4328.7-1999
Carburized layer carbon concentration should be between 0.7~1.05. 4.2.6.2
Carburized parts that need to be machined should have a hardness value of HRC25~HRC30. 4.2.6.3
4.2.7 Nitrided parts
Nitrided parts that are mainly used to improve surface hardness and wear resistance must be tempered before nitriding, and their hardness should be HRC28~HRC33. 4.2.7.1
Parts are not allowed to have decarburized layer, oil stains and rust spots before nitriding. The deformation of the parts is generally 1/3~1/2 of the tolerance of the finished product. 4.2.8
Carbon-ammonia-nitrogen co-carburizing parts
The surface hardness of carbon-nitrogen co-carburizing parts is HRC58~HRC64, and the base hardness is HRC33~HRC48. The concentration of carbon-nitrogen co-carburizing is 0.8%~0.95%C and 0.25%~0.4%N, and the total amount of carbon and nitrogen is between 1.0%~1.25%. 4.2.8.3
The depth S of carbon-nitrogen co-carburizing:
a) Light load S≤0.5mm;
b) Heavy load S≥0.5mm;
c) When the original carburized parts are changed to carbon-nitrogen co-carburizing, the depth should be increased by one third of the original carburized layer depth. 4.2.8.4 The deformation of the co-carburized parts is allowed to be 1/3~1/2 of the tolerance. 5 Test methods
5.1 Appearance inspection: Generally, parts should be observed with the naked eye or a low-power magnifying glass to see if there are cracks, burns, bruises, pitting, rust, etc. on the surface. Important parts or parts that are prone to cracks should be inspected for cracks. 5.2 Hardness inspection
5.2.1 The hardness inspection of parts should be carried out in accordance with the following rules: a) Rockwell hardness shall be carried out in accordance with the provisions of GB/T230: b) Brinell hardness shall be carried out in accordance with the provisions of GB/T231; c) Vickers hardness shall be carried out in accordance with the provisions of GB/T4340: d) Surface Rockwell hardness shall be carried out in accordance with the provisions of GB/T1818; e) Other relevant inspection methods: Generally, parts treated by annealing, normalizing, and quenching and tempering shall be inspected by Brinell (HB) hardness tester, parts treated by quenching or quenching and tempering shall be inspected by Rockwell hardness tester, and parts treated by nitriding or with thin hardened layers shall be inspected by Vickers hardness tester. 5.2.2 Before checking the hardness, the inspector should be familiar with the error of the hardness tester, clean the surface of the part and remove the oxide scale. 5.2.3 The hardness inspection of the quenched part should be 1 to 3 places, with no less than three points in each place, and the average value should be within the hardness value range required by the drawing. 5.3 The inspection of the deformation of the parts should be carried out with different inspection tools according to the process regulations. 5.4 Metallographic inspection is generally not carried out except in the following cases. a) Important parts in the product, which are required by the process regulations: b) The inspector has doubts about this batch and this part: c) Trial production parts after batch or large-scale production and process changes. 5.5 Mechanical property test
5.5.1 All parts with special requirements for mechanical properties should be tested according to their requirements. 5.5.2 The test material (which can also be cut from the part) should be subjected to the same heat treatment as the part. 5.6 Carburizing inspection
JB/T4328.7—1999
5.6.1 The depth of the carburized layer is calculated based on the sum of the hypereutectoid layer, eutectoid layer and 1/2 of the transition layer. 5.6.2 For general carburized parts, only the appearance is measured. The carbon content inspection of the carburized layer of more important parts shall comply with the provisions of 4.2.6.2. 5.7 Cyaniding inspection
5.7.1 The depth of the nitriding (nitriding) layer shall be calculated based on the sum of the compound thickness and the total transition diffusion layer. The continuous thickness of the compound layer shall reach 0.015~0.030mm.
5.7.2 Appearance inspection: there shall be no cracks or looseness visible to the naked eye on the surface. 5.7.3 The number of nitriding test pieces in the heat treatment shall be determined by the inspector. 5.8 Other inspections
5.8.1 The inspection of the decarburized layer shall comply with the provisions of GB/T224. 5.8.2 The grain size of steel shall comply with the provisions of YB/T5148. 5.8.3 The inspection of macrostructure defects of structural steel shall be evaluated in accordance with the provisions of GB/T1979. 5.8.4 The inspection of non-metallic inclusions shall be evaluated in accordance with the provisions of GB/T10561. 5.8.5 Parts with permeability requirements shall be inspected and tested in accordance with the provisions of GB/T225. 6 Inspection rules
The heat-treated parts shall be inspected by the quality inspection department according to the drawings and relevant technical documents, and the ordering unit may also conduct re-inspection. 6.1
6.2 After the parts are heat-treated, the appearance, hardness, deformation, layer depth, decarburization, metallographic structure, material, mechanical properties, carburizing, nitriding and other items shall be inspected. The inspection method shall be carried out in accordance with the following requirements. 6.3www.bzxz.net
The inspection items and inspection quantity of heat-treated parts shall be as specified in Table 6. Table 6
Parts categories
General parts
Important parts
Inspection items
Inspection rate
Each batch≥3%
Not less than 3 pieces
Each batch≥5%
Not less than 3 pieces
≥10%
≥5% but
Not less than 3 pieces
6.4·When inspecting according to the provisions of Table 6, if any unqualified parts are found, a full inspection shall be carried out. 7 Marking and Certificate
7.1. The heat-treated parts that have passed the inspection shall be accompanied by the mark of the quality inspection department of the manufacturer. 7.2 Heat-treated parts shall be accompanied by a certificate of conformity before leaving the factory, which shall include the following: a) manufacturer name or code;
b) part drawing code, name, quantity; c) material brand;
d) inspection items and inspection results:
e) this standard number.
Metallographic structure
Deepness of hardened layer
According to process regulations
Mechanical properties
JB/T4328.7—1999
Appendix A
(Suggested Appendix)
Deformation tolerance before and after quenching
For the deformation tolerance before and after quenching, please refer to Table A1, Table A2, Table A3, Table A4, Table A5. Table A1
Deformation tolerance and allowance of spline shaft quenching (including carburizing quenching)Deformation
Allowance on both sides of key side
Deformation before quenching
Deformation after quenching
Note: Deformation refers to the spline part only. The rest of the parts are still considered as general shafts. Table A2 of deformation tolerance and allowance of straight
flat plate parts before and after hardening
Part width
Part length
≤300
301~1000
1001~2000
Allowance on each side
0.30~0.40
0.40-0.50
0.50~0.70
Deformation before hardening
Double-sided allowance of spiral
Deformation before hardening≤
Deformation after hardening
Deformation after hardening
Allowance on each side
0.40~0.50
0.50~0.70
0.60~0.80||t t||101~200
Deformation before hardening
Deformation tolerance and excess modulus of worm shaft quenching (including carburizing and quenching)
0.30~0.10
0.40~0.50
Deformation after hardening
0.50~0.60
JB/T4328.7-1999||t t||0000109
001580
S6'0-080
06:0~0L0
060020
tt||0200 90 | | tt | t||09 :0-0s0
S90~SS0
008-109
050000
o50-050
09:0~0s0
009-1st
Ss0-St0
s90-ss0
st~100||tt ||0 9'0~0S'0
St0~sc0
050~000
09°0~0S:0
s9'0-ss0
09°0~050
05~0t0
50~0t0
09:0~0S0
s9' 0~ss0
09°0~0S0
050000
000~000
050~00
Ss0~S0
001~1s
06:0~020
0L0~090
09'0-0s0
0 00~050
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