This standard specifies the heat treatment process, equipment and quality inspection methods for ordinary and low alloy ductile iron (hereinafter referred to as ductile iron). JB/T 6051-1992 Heat treatment process and quality inspection for ductile iron JB/T6051-1992 Standard download decompression password: www.bzxz.net

Machinery Industry Standard of the People's Republic of China
JB/T 6051-1992
Heat treatment process and quality inspection of ductile iron1992-05-05Published
Ministry of Machinery Industry of the People's Republic of China
Standard Download Network (www.bzxzw.com)
1993-07-01Implementation
Mechanical Industry Standard of the People's Republic of China
Heat treatment process and quality inspection of ductile iron1 Subject content and scope of application
JB/T6051-1992
This standard specifies the heat treatment process, equipment and quality inspection method of ordinary and low alloy ductile iron (hereinafter referred to as ductile iron). This standard applies to the annealing, normalizing, quenching, tempering and isothermal heat treatment process of ductile iron. For other ductile irons, the process requirements may be referred to and implemented. 2bzxz.net
Cited standards
GB1348
GB2160
GB4340
GB5614
GB7232
GB9441
GB/T12603
3Terms
Metal tensile test method
Metal Rockwell hardness test method
Metal Brinell hardness test method
Ductile iron castings||tt ||Metal Charpy (V-notch) impact test methodMetal Vickers hardness test method
Name, definition and code of heat treatment state of cast ironMetal heat treatment process terminology
Method for determining effective heating zone of heat treatment furnace
Classification and code of metal heat treatment process
3.1 High-temperature graphitization annealing
For castings with eutectic cementite and primary cementite in the as-cast structure, heat to above A2 temperature, keep warm, then furnace cool to room temperature or furnace cool to below A temperature and air cool to obtain pearlite or pearlite + ferrite matrix structure. 3.2 Low-temperature graphitization annealing
For castings with as-cast structure of pearlite and graphite or pearlite, ferrite and graphite, heat to slightly below A temperature, keep warm, then furnace cool to room temperature or furnace cool to below A temperature and air cool to obtain ferrite-based matrix structure. 3.3 Complete austenitization normalizing
The casting is heated above the A-tab temperature, so that the matrix is ​​completely transformed into austenite, and then air-cooled, air-cooled or mist-cooled after being taken out of the furnace to obtain a matrix structure dominated by pearlite.
3.4 ​​Partial austenitization normalizing
The casting is heated to A temperature and kept warm between A-tab, and then air-cooled, air-cooled or mist-cooled after being taken out of the furnace to obtain a matrix structure of pearlite and ferrite. 3.5 Low-carbon austenitization normalizing
The casting is heated to slightly below the A temperature, kept warm, and then quickly heated to a temperature higher than A2, without keeping warm, and air-cooled, air-cooled or mist-cooled after being taken out of the furnace to obtain a matrix structure of pearlite and ferrite. Approved by the Ministry of Machinery and Electronics Industry on May 5, 1992 Standard download website (www.bzxzw.com)
Implementation on July 1, 1993
3.6 Complete austenitization quenching
JB/T6051-1992
The casting is heated to above A temperature and kept warm, so that the matrix is ​​completely transformed into austenite, then taken out of the furnace and quenched into a constant temperature bath at a temperature below A, kept warm, taken out and air-cooled, and a matrix structure mainly composed of bainite or bainite + residual austenite is obtained. Note: A2 - The temperature at which ferrite is completely transformed into austenite during the heating process. As
The temperature at which austenite begins to form during heating. The temperature at which austenite completely transforms into pearlite and ferrite during cooling. 4 Application of heat treatment process
4.1 High temperature graphitization annealing is used for castings with a large amount of eutectic cementite and alloy element segregation in the matrix structure. 4.2 Low temperature graphitization annealing
It is used for castings with no eutectic cementite in the matrix structure and a high amount of pearlite, which require high plasticity and high toughness.
4.3 Stress relief annealing is used to eliminate the casting stress of castings or eliminate the residual stress caused by welding, machining, hot working, etc. of castings.
4.4 Complete austenitization normalizing is used for castings with a small amount of eutectic cementite in the matrix structure or a small degree of alloy element segregation, and which require higher strength.
4.5 Partial austenitizing normalizing is used for castings with relatively uniform matrix structure, no eutectic cementite, and required to have certain strength and toughness. 4.6 Low-carbon austenitizing normalizing is used for castings with relatively uniform matrix structure, no eutectic cementite, and required to have higher toughness. 4.7 Quenching and tempering is used for castings with good comprehensive mechanical properties or large-scale castings whose performance requirements are difficult to meet by normalizing. 4.8 Tempering is used for castings that stabilize the structure, improve toughness, and eliminate stress after quenching. 4.9 Upper bainite isothermal quenching obtains a matrix structure dominated by upper bainite and residual austenite, which is used for ductile iron parts that require high strength and high toughness.
Lower bainite isothermal quenching obtains a matrix structure dominated by lower bainite and a small amount of martensite, which is used for ductile iron parts that require high strength, high hardness, and high wear resistance.
5 Heat treatment equipment
5.1 Heating equipment
Thermal insulation accuracy of the effective heating zone of the heat treatment furnace (see Table 1); the detection method of the effective heating zone shall be implemented in accordance with the provisions of GB9452. Table 1
Process type
High temperature graphitization annealing
Low temperature graphitization annealing
Stress relief annealing
Complete austenitization normalizing
Low carbon austenitization normalizing
Thermal insulation accuracy
Process type
Partial austenitization normalizing
Complete austenitization annealing
Complete austenitization isothermal annealing
Thermal insulation accuracy
JB/T 60511992
The flame of the gas, oil and coal-fired heating furnace cannot directly contact the workpiece. 5.1.2
5.1.3 The atmosphere in the controlled atmosphere heating furnace should be adjusted and controlled according to the requirements of the heat treatment process. 5.1.4 When using a salt bath furnace for heating, the salt bath should be fully deoxidized, and the salt bath used should not have any corrosion or other harmful effects on the castings. 5.1.5
Less oxidizing heating equipment should be used as much as possible. 5.1.6 Continuous operation furnaces should be able to adjust the conveying speed so that the treated parts can maintain the necessary heating time in the furnace. 5.2 Cooling equipment and cooling medium
5.2.1 The cooling equipment should ensure uniform cooling of all parts of the treated parts, and the cooling tank should be equipped with a stirring device or other devices with the same effect to ensure proper circulation of the cooling medium. If necessary, it should be equipped with a regulating device to ensure the use temperature of the quenching medium. 5.2.2 The cooling equipment should be able to ensure the use temperature of the quenching cooling medium (see Table 2). Table 2
Cooling equipment
Cooling medium
Inorganic water-soluble quenching liquid
Ordinary kerosene
Isothermal quenching liquid
Using temperature ℃
20~100
Predetermined temperature T±15
5.2.3 The cooling performance of the cooling medium shall meet the process requirements and shall not produce corrosion or other harmful effects on the treated parts. 5.2.4 Continuous cooling equipment shall ensure the adjustment of the conveying speed. 5.3 Temperature measurement and control equipment
5.3.1 Heat treatment heating and rate cooling equipment shall be equipped with temperature measuring and temperature control devices. Each heating zone of the continuous furnace shall be equipped with a recording device to track the change of the treatment temperature over time.
Total error of the temperature measuring device (see Table 3).
Predetermined temperature
Total error
Calibration and maintenance of heat treatment equipment
±(T/100)
Heat treatment equipment should be regularly inspected and maintained, thermocouples and temperature control instruments should be calibrated, effective heating area of ​​heat treatment furnace should be determined according to GB9452, and relevant records should be kept.
Heat treatment process
6.1 Preparation before heat treatment
6.1.1 Understand the chemical composition, heat treatment process requirements and metallographic structure of the parts to be treated. Its original structure should meet the technical requirements, otherwise pretreatment is required.
6.1.2 Check the surface, appearance, geometric shape and size of the parts to be treated. No surface defects such as cracks and severe scratches are allowed. If necessary, clean, wash, dry and apply anti-oxidation coating to the parts to be treated. 6.1.3
Check whether the heat treatment equipment and instruments are normal. 3
6.2 Process Specifications
6.2.1 Heating Temperature
JB/T6051—1992
The heating temperature of the treated part is mainly determined by factors such as the phase change point of the material, the original structure, the shape and size of the workpiece and the purpose of treatment. For details, please refer to Appendix A (reference part).
6.2.2 Heating speed
Generally, the heating method of low-temperature furnace entry and furnace temperature rise is adopted. Preheating should be carried out for parts with large cross-sections and complex shapes. For parts with small size and simple shape, they can also be heated in the furnace at the heat treatment heating temperature, but their quality should not be affected. 6.2.3 Holding time
Reasonable holding time should be formulated according to factors such as heating temperature, heating medium, treatment shape, size, furnace loading and original organization. 6.2.4 Cooling speed
According to the process requirements, the appropriate cooling speed is selected to make the treated parts reach the required organization and performance. Annealed parts are generally cooled to below 550℃ and air-cooled when the furnace temperature is cooled. For workpieces with smaller internal stress, the furnace temperature should be cooled to below 350℃ and air-cooled when the furnace temperature is cooled.
Normalized parts are generally air-cooled. For some large parts or castings with higher pearlite content in the matrix organization, air cooling and mist cooling can be used. The quenching of quenched and tempered parts is generally cooled by oil cooling and water-soluble quenching liquid. For simple-shaped castings, water cooling or other medium cooling can also be used. Air cooling is generally used for tempering.
Isothermal quenching parts are generally cooled by hot bath cooling, and the hot bath temperature is generally 230~380℃. 6.3 Subsequent processes of heat treatment
6.3.1 The workpiece after heat treatment can be cleaned or descaled if necessary. 6.3.2 The workpiece straightened after heat treatment can be subjected to stress relief treatment if necessary. 6.4 Heat treatment process record
The operation mode, process flow, conditions and operators in the heat treatment process should be recorded and archived. 7 Heat treatment quality inspection
7.1 Quality inspection items
According to the use of the treated parts, they can be divided into ordinary parts, important parts and special important parts. The corresponding quality inspection contents are shown in Table 4. Table 4
Ordinary parts
Important parts
Special important parts
7.2 Contents and requirements of quality inspection work
7.2.1 Appearance
(1) Appearance,
Inspection items
(2) Mechanical properties, (3) Deformation
(2) Mechanical properties, (3) Deformation, (4) Metallographic structure (1) Appearance,
(1) Appearance, (2) Mechanical properties, (3) Deformation, (4) Metallographic structure, (5) NDT The surface of the processed parts shall not have cracks, damage or other defects that may affect its performance and use. Residual salt, rust, etc. are not allowed. 7.2.2 Mechanical properties
7.2.2.1 Hardness
JB/T6051-1992
Hardness determination can be carried out on castings or samples from the same furnace. The hardness fluctuation range is shown in Table 5. Table 5
Processing method
7.2.2.2 Tensile strength, elongation and impact value Annealing
Isothermal annealing
Determination of tensile strength, elongation and impact value can be carried out using single casting or attached casting test blocks, and meet the relevant provisions of GB1348. Single casting test blocks should be cast in the same furnace as the casting and heat treated in the same furnace. Attached casting test blocks should be cut from the casting after heat treatment. If sampling is taken from the casting body, the sampling location and the performance indicators to be achieved must be agreed upon by the supply and demand parties before heat treatment. Tensile strength and elongation are the basis for acceptance and must meet the grade requirements. Impact value is only tested when it is clearly required. 7.2.3 Metallographic structure
The spheroidizing level of ductile iron shall not be lower than level 4, and the matrix structure shall meet the technical requirements. 7.2.4 Deformation
The deformation of the treated parts shall not affect the subsequent mechanical processing and use, and shall meet the technical requirements. 7.3 Quality inspection method
7.3.1 Flaw detection test
Cracks and surface scratches can be detected by visual inspection, fluorescent flaw detection, magnetic particle flaw detection and other methods. Demagnetization should be performed after magnetic particle flaw detection. 7.3.2 Mechanical property test
Hardness test can be carried out in accordance with the provisions of GB230, GB231, GB4340, etc. The tensile test shall be carried out in accordance with the provisions of GB228.
Impact test shall be carried out in accordance with the provisions of GB2106. 7.3.3 Metallographic structure inspection
It shall be carried out in accordance with the provisions of GB9441 and relevant standards. 7.4 Quality Supervision
Inspectors shall conduct inspections in accordance with the requirements of the process documents and relevant standards, supervise the correct implementation of the heat treatment process, and submit a quality inspection report.
8 Status marking of treated parts
After the treated parts have passed the inspection, they shall be marked as qualified, and the ductile iron grade, heat treatment status, heat treatment manufacturer and date, workpiece drawing number, name and quantity, etc. shall be indicated. The ductile iron grade shall be implemented in accordance with GB1348. The heat treatment status code marking method shall be implemented in accordance with GB5614.
Process method
Process temperature
Graphitization
+ (50~
Graphitization
Stress relief
Common temperature
560~620
JB/T 60511992
Ductile iron heat treatment process temperature
(reference part)
Complete austenitization
+(50~
Partial austenitization
Low carbon austenitization
(30-50)
After heat preservation, quickly heat to
(30-50)
No insulation
Complete austenitization
(30~50)
Common temperature
500~600
Isothermal quenching
Lower Bainite
Upper Bainite
Body isothermal
(30~50)
Common isothermal
Firing temperature
350-380
Body isothermal|| tt||(30~50)
Common isothermal
Firing temperature
230-330
Ordinary ductile iron
Low alloy
JB/T6051-1992
Phase transition temperature of two ductile iron materials
(reference)
Chemical composition
Note: The intersection point is determined by thermal expansion method.
Additional instructions:| |tt||This standard was proposed and managed by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry. Mo
This standard was drafted by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry and the First Automobile Works. The main drafters of this standard are Li Quangui, Liu Changsuo, Chen Yunbo and Chen Weiming. Matrix
Phase transition point
People's Republic of China
Mechanical Industry Standard
Heat treatment process and quality inspection of ductile iron JB/T 60511992
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2, Shouti South Road, Beijing
Postal Code: 100044)
1/16 Printing Sheet 3/4
Format 880×1230
First Edition in January 1993
Print 1-500
Word 14,000
First Printing in January 1993
Price 10.00 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn2661_09 /1 Quality inspection items
According to the use of the processed parts, they can be divided into ordinary parts, important parts and special important parts. The corresponding quality inspection contents are shown in Table 4. Table 4
Ordinary parts
Important parts
Special important parts
7.2 Contents and requirements of quality inspection work
7.2.1 Appearance
(1) Appearance,
Inspection items
(2) Mechanical properties, (3) Deformation
(2) Mechanical properties, (3) Deformation, (4) Metallographic structure (1) Appearance,
(1) Appearance, (2) Mechanical properties, (3) Deformation, (4) Metallographic structure, (5) NDT The surface of the processed parts shall not have cracks, damage and other defects that affect its performance and use. Residual salt, rust, etc. are not allowed. 7.2.2 Mechanical properties
7.2.2.1 Hardness
JB/T6051-1992
Hardness determination can be carried out on castings or samples from the same furnace. The hardness fluctuation range is shown in Table 5. Table 5
Processing method
7.2.2.2 Tensile strength, elongation and impact value Annealing
Isothermal annealing
Determination of tensile strength, elongation and impact value can be carried out using single casting or attached casting test blocks, and meet the relevant provisions of GB1348. Single casting test blocks should be cast in the same furnace as the casting and heat treated in the same furnace. Attached casting test blocks should be cut from the casting after heat treatment. If sampling is taken from the casting body, the sampling location and the performance indicators to be achieved must be agreed upon by the supply and demand parties before heat treatment. Tensile strength and elongation are the basis for acceptance and must meet the grade requirements. Impact value is only tested when it is clearly required. 7.2.3 Metallographic structure
The spheroidizing level of ductile iron shall not be lower than level 4, and the matrix structure shall meet the technical requirements. 7.2.4 Deformation
The deformation of the treated parts shall not affect the subsequent mechanical processing and use, and shall meet the technical requirements. 7.3 Quality inspection method
7.3.1 Flaw detection test
Cracks and surface scratches can be detected by visual inspection, fluorescent flaw detection, magnetic particle flaw detection and other methods. Demagnetization should be performed after magnetic particle flaw detection. 7.3.2 Mechanical property test
Hardness test can be carried out in accordance with the provisions of GB230, GB231, GB4340, etc. The tensile test shall be carried out in accordance with the provisions of GB228.
Impact test shall be carried out in accordance with the provisions of GB2106. 7.3.3 Metallographic structure inspection
It shall be carried out in accordance with the provisions of GB9441 and relevant standards. 7.4 Quality Supervision
Inspectors shall conduct inspections in accordance with the requirements of the process documents and relevant standards, supervise the correct implementation of the heat treatment process, and submit a quality inspection report.
8 Status marking of treated parts
After the treated parts have passed the inspection, they shall be marked as qualified, and the ductile iron grade, heat treatment status, heat treatment manufacturer and date, workpiece drawing number, name and quantity, etc. shall be indicated. The ductile iron grade shall be implemented in accordance with GB1348. The heat treatment status code marking method shall be implemented in accordance with GB5614.
Process method
Process temperature
Graphitization
+ (50~
Graphitization
Stress relief
Common temperature
560~620
JB/T 60511992
Ductile iron heat treatment process temperature
(reference part)
Complete austenitization
+(50~
Partial austenitization
Low carbon austenitization
(30-50)
After heat preservation, quickly heat to
(30-50)
No insulation
Complete austenitization
(30~50)
Common temperature
500~600
Isothermal quenching
Lower Bainite
Upper Bainite
Body isothermal
(30~50)
Common isothermal
Firing temperature
350-380
Body isothermal|| tt||(30~50)
Common isothermal
Firing temperature
230-330
Ordinary ductile iron
Low alloy
JB/T6051-1992
Phase transition temperature of two ductile iron materials
(reference)
Chemical composition
Note: The intersection point is determined by thermal expansion method.
Additional instructions:| |tt||This standard was proposed and managed by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry. Mo
This standard was drafted by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry and the First Automobile Works. The main drafters of this standard are Li Quangui, Liu Changsuo, Chen Yunbo and Chen Weiming. Matrix
Phase transition point
People's Republic of China
Mechanical Industry Standard
Heat treatment process and quality inspection of ductile iron JB/T 60511992
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2, Shouti South Road, Beijing
Postal Code: 100044)
1/16 Printing Sheet 3/4
Format 880×1230
First Edition in January 1993
Print 1-500
Word 14,000
First Printing in January 1993
Price 10.00 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn2661_09 /1 Quality inspection items
According to the use of the processed parts, they can be divided into ordinary parts, important parts and special important parts. The corresponding quality inspection contents are shown in Table 4. Table 4
Ordinary parts
Important parts
Special important parts
7.2 Contents and requirements of quality inspection work
7.2.1 Appearance
(1) Appearance,
Inspection items
(2) Mechanical properties, (3) Deformation
(2) Mechanical properties, (3) Deformation, (4) Metallographic structure (1) Appearance,
(1) Appearance, (2) Mechanical properties, (3) Deformation, (4) Metallographic structure, (5) NDT The surface of the processed parts shall not have cracks, damage and other defects that affect its performance and use. Residual salt, rust, etc. are not allowed. 7.2.2 Mechanical properties
7.2.2.1 Hardness
JB/T6051-1992
Hardness determination can be carried out on castings or samples from the same furnace. The hardness fluctuation range is shown in Table 5. Table 5
Processing method
7.2.2.2 Tensile strength, elongation and impact value Annealing
Isothermal annealing
Determination of tensile strength, elongation and impact value can be carried out using single casting or attached casting test blocks, and meet the relevant provisions of GB1348. Single casting test blocks should be cast in the same furnace as the casting and heat treated in the same furnace. Attached casting test blocks should be cut from the casting after heat treatment. If sampling is taken from the casting body, the sampling location and the performance indicators to be achieved must be agreed upon by the supply and demand parties before heat treatment. Tensile strength and elongation are the basis for acceptance and must meet the grade requirements. Impact value is only tested when it is clearly required. 7.2.3 Metallographic structure
The spheroidizing level of ductile iron shall not be lower than level 4, and the matrix structure shall meet the technical requirements. 7.2.4 Deformation
The deformation of the treated parts shall not affect the subsequent mechanical processing and use, and shall meet the technical requirements. 7.3 Quality inspection method
7.3.1 Flaw detection test
Cracks and surface scratches can be detected by visual inspection, fluorescent flaw detection, magnetic particle flaw detection and other methods. Demagnetization should be performed after magnetic particle flaw detection. 7.3.2 Mechanical property test
Hardness test can be carried out in accordance with the provisions of GB230, GB231, GB4340, etc. The tensile test shall be carried out in accordance with the provisions of GB228.
Impact test shall be carried out in accordance with the provisions of GB2106. 7.3.3 Metallographic structure inspection
It shall be carried out in accordance with the provisions of GB9441 and relevant standards. 7.4 Quality Supervision
Inspectors shall conduct inspections in accordance with the requirements of the process documents and relevant standards, supervise the correct implementation of the heat treatment process, and submit a quality inspection report.
8 Status marking of treated parts
After the treated parts have passed the inspection, they shall be marked as qualified, and the ductile iron grade, heat treatment status, heat treatment manufacturer and date, workpiece drawing number, name and quantity, etc. shall be indicated. The ductile iron grade shall be implemented in accordance with GB1348. The heat treatment status code marking method shall be implemented in accordance with GB5614.
Process method
Process temperature
Graphitization
+ (50~
Graphitization
Stress relief
Common temperature
560~620
JB/T 60511992
Ductile iron heat treatment process temperature
(reference part)
Complete austenitization
+(50~
Partial austenitization
Low carbon austenitization
(30-50)
After heat preservation, quickly heat to
(30-50)
No insulation
Complete austenitization
(30~50)
Common temperature
500~600
Isothermal quenching
Lower Bainite
Upper Bainite
Body isothermal
(30~50)
Common isothermal
Firing temperature
350-380
Body isothermal|| tt||(30~50)
Common isothermal
Firing temperature
230-330
Ordinary ductile iron
Low alloy
JB/T6051-1992
Phase transition temperature of two ductile iron materials
(reference)
Chemical composition
Note: The intersection point is determined by thermal expansion method.
Additional instructions:| |tt||This standard was proposed and managed by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry. Mo
This standard was drafted by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry and the First Automobile Works. The main drafters of this standard are Li Quangui, Liu Changsuo, Chen Yunbo and Chen Weiming. Matrix
Phase transition point
People's Republic of China
Mechanical Industry Standard
Heat treatment process and quality inspection of ductile iron JB/T 60511992
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2, Shouti South Road, Beijing
Postal Code: 100044)
1/16 Printing Sheet 3/4
Format 880×1230
First Edition in January 1993
Print 1-500
Word 14,000
First Printing in January 1993
Price 10.00 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn2661_09 /4 Quality supervision
Inspectors should conduct inspections according to the requirements of the process documents and the provisions of relevant standards, supervise the correct implementation of the heat treatment process, and submit a quality inspection report.
8 Status marking of treated parts
After the treated parts are inspected and qualified, they must be marked with the ductile iron grade, heat treatment status, heat treatment manufacturer and date, workpiece drawing number, name and quantity, etc. The ductile iron grade shall be implemented in accordance with the provisions of GB1348. The heat treatment status code marking method shall be implemented in accordance with the provisions of GB5614.
Process method
Process temperature
Graphitization
+ (50~
Graphitization
Stress relief
Common temperature
560~620
JB/T 60511992
Ductile iron heat treatment process temperature
(reference part)
Complete austenitization
+(50~
Partial austenitization
Low carbon austenitization
(30-50)
After heat preservation, quickly heat to
(30-50)
No insulation
Complete austenitization
(30~50)
Common temperature
500~600
Isothermal quenching
Lower Bainite
Upper Bainite
Body isothermal
(30~50)
Common isothermal
Firing temperature
350-380
Body isothermal|| tt||(30~50)
Common isothermal
Firing temperature
230-330
Ordinary ductile iron
Low alloy
JB/T6051-1992
Phase transition temperature of two ductile iron materials
(reference)
Chemical composition
Note: The intersection point is determined by thermal expansion method.
Additional instructions:| |tt||This standard was proposed and managed by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry. Mo
This standard was drafted by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry and the First Automobile Works. The main drafters of this standard are Li Quangui, Liu Changsuo, Chen Yunbo and Chen Weiming. Matrix
Phase transition point
People's Republic of China
Mechanical Industry Standard
Heat treatment process and quality inspection of ductile iron JB/T 60511992
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2, Shouti South Road, Beijing
Postal Code: 100044)
1/16 Printing Sheet 3/4
Format 880×1230
First Edition in January 1993
Print 1-500
Word 14,000
First Printing in January 1993
Price 10.00 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn2661_09 /4 Quality supervision
Inspectors should conduct inspections according to the requirements of the process documents and the provisions of relevant standards, supervise the correct implementation of the heat treatment process, and submit a quality inspection report.
8 Status marking of treated parts
After the treated parts are inspected and qualified, they must be marked with the ductile iron grade, heat treatment status, heat treatment manufacturer and date, workpiece drawing number, name and quantity, etc. The ductile iron grade shall be implemented in accordance with the provisions of GB1348. The heat treatment status code marking method shall be implemented in accordance with the provisions of GB5614.
Process method
Process temperature
Graphitization
+ (50~
Graphitization
Stress relief
Common temperature
560~620
JB/T 60511992
Ductile iron heat treatment process temperature
(reference part)
Complete austenitization
+(50~
Partial austenitization
Low carbon austenitization
(30-50)
After heat preservation, quickly heat to
(30-50)
No insulation
Complete austenitization
(30~50)
Common temperature
500~600
Isothermal quenching
Lower Bainite
Upper Bainite
Body isothermal
(30~50)
Common isothermal
Firing temperature
350-380
Body isothermal|| tt||(30~50)
Common isothermal
Firing temperature
230-330
Ordinary ductile iron
Low alloy
JB/T6051-1992
Phase transition temperature of two ductile iron materials
(reference)
Chemical composition
Note: The intersection point is determined by thermal expansion method.
Additional instructions:| |tt||This standard was proposed and managed by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry. Mo
This standard was drafted by the Beijing Electromechanical Research Institute of the Ministry of Machinery and Electronics Industry and the First Automobile Works. The main drafters of this standard are Li Quangui, Liu Changsuo, Chen Yunbo and Chen Weiming. Matrix
Phase transition point
People's Republic of China
Mechanical Industry Standard
Heat treatment process and quality inspection of ductile iron JB/T 60511992
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2, Shouti South Road, Beijing
Postal Code: 100044)
1/16 Printing Sheet 3/4
Format 880×1230
First Edition in January 1993
Print 1-500
Word 14,000
First Printing in January 1993
Price 10.00 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn2661_09 /
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