Some standard content:
IC5 25. 200
Machinery Industry Standard of the People's Republic of China
JB8429—1999
Deep carburizing
1999-06-24 Issued
National Bureau of Machinery Industry
2000-01-01 ImplementationwwW.bzxz.Net
JBrT.8929-1999
This standard was proposed by the National Technical Committee for Heat Treatment Standardization and was submitted to: The drafting unit of this standard is Xi'an Heavy Technology University. The main drafters of this standard are Yue Jungang, Liu Jinli, Zhao Zhuanqun, and Zhu Zhi. 1 Scope
Machinery Industry Standard of the People's Republic of China
Deep carburizing
Deep carburizing
This standard specifies the basic requirements of deep carburizing materials, processes, equipment, quality inspection & safety technology. This standard applies to deep carburizing treatment of workpieces. 2 Referenced standards
JB/T8929—1999
The texts contained in the following standards become the meaning of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest version of the following standards: GB/T 224—1587
GB/T3077-1988
GB/T7232—1987
GB/T 9450—1998
GBT9452—1998
GB157351995
GA/T169231997
G71924-99
RT39991999
: 4.1—1992
JB.T6141.3—1992
JB/T69SS—1993
JB.T9209—1999
YB.T51481993
3 Definition
Method for determination of the depth of debonding layer of steel
Technical conditions for alloy drill steel
Terminology of metal heat treatment process
Determination and verification of the effective hardening depth of steel parts by carbon annealing Effective original heat zone determination lamp method
Safety and health requirements for the production process of reheat treatment of steel parts
Reheating and tempering of steel parts
Carbon and carbon-nitrogen content of steel parts
Carbon layer spheroidization effect of heavy gears after gold cabinet inspection Heavy-duty gear material hard metallographic inspection
Technical requirements for heat treatment belts
Chemical heat treatment technology system
Method for determination of average grain size of metals
The following definitions are used in this standard.
Deep carburizing
3.1:
In order to increase the carbon content of the surface layer of the workpiece and reach a certain carbon concentration, the workpiece is heated in a carburizing medium and heated to a high temperature to make the carbon original rate enter the surface, so that the effective hardening layer depth reaches more than 311n. Other metal heat treatment process terms appearing in this standard are defined in accordance with G7272. 4 Deep carburizing materials
4.【Steel selection
Approved by the State Machinery Industry Bureau on June 24, 1999, and implemented on January 1, 2000
JB/18929-1999
Deep carburizing can be carried out on the steel types specified in JR/T999. Deep carburizing steel types can be selected according to the performance requirements of parts. Parts with special requirements can be selected according to the needs, but fine-grained steel should be used. A.2 Material identification
Before deep carburizing, the steel type must be confirmed and a material component analysis report must be submitted. Chemical composition, low-carbon organization. Non-standard materials should comply with the provisions of JR/T3077. If the standard is not met, it can be confirmed through negotiation. The loose material and primary performance indicators must be confirmed.
4.3 Material internal quality and inspection
Material internal quality inspection content includes: metal average grain size and metal internal defects: metal average grain size measurement can be carried out according to the method specified in Y口T5148: internal defects can be tested by flaw detection method, or by agreement with the user: adopt joint decision 5 Deep carburizing equipment
5.1 Deep carburizing heating equipment
5.1.1 The heating equipment shall meet the requirements of temperature uniformity and temperature control accuracy in the effective heating zone. The temperature of the effective heating zone can be measured according to GB452.
5.1.2 The heating equipment shall meet the requirements of atmosphere uniformity and carbon potential control accuracy. 5.1.3 The raw materials for preparing gas oxygen must meet the technical conditions specified in JA/TQ209. 5.1.4 The workpiece shall be installed in the deep layer accurately. It does not affect the deep carburizing flux. 5.1.5 Heating equipment should be reliable enough, and regular inspection and maintenance should be carried out to ensure that it is not damaged during the heating process. 5.2 Spheroidizing annealing and quenching heating equipment
5.2.1 The temperature in the effective heating zone is uniformly within 10° of the set temperature. 5.2.2 The quenching furnace must be equipped with a controllable protective atmosphere device. 5.3 Cooling equipment
5.3.1 The quenching cooling equipment is generally equipped with a heating and cooling device for the quenching medium, with a controllable temperature control system, 5.3.z The use range of the quenching medium should comply with the provisions of GH/T[6924. 5.3.3 The quenching medium should comply with the provisions of JB/T6955. 5.3.4 The deep clean carbon grade quenching pit or cooling equipment should be able to pass the expansion gas or filter the organic liquid. Special requirements can be equipped with material dynamic control equipment.
5.4 Heating equipment
5.4.1 The temperature uniformity of the effective heating area shall be within ±[0T at the set temperature. 5.5 Temperature and carbon potential measurement system
5.5.1 The carbon potential measurement and control system shall meet the requirements of 5.1.1, 5.2.1, 5.3.1, and 5.4.1. 5.5.2 The carbon potential measurement and recording system shall meet the requirements of 5.1.2. 5.5.3 There must be a recording device for temperature and carbon potential. 5.5.4 The temperature control accuracy shall be 1%T (±400% when lower than 400%) within the indicated scale range of the predetermined temperature. 5.5.5 Within the indicated scale range of the predetermined carbon potential. Carbon potential control accuracy ±(.05% C, 5. Equipment maintenance and calibration
Scheduled maintenance, maintenance and calibration should be formulated and strictly carried out with detailed records. 2
6 Deep-layer iodine process
6,! Preparation for processing
JB8929-1999
6.! . " Know the quality requirements of the workpiece, determine the anti-adding measures used in the fall, understand the material brand (or chemical composition; and pre-treatment conditions,
6.1.2 Check whether the scale has oxidation and rust: whether there is dents or cracks, and conduct non-destructive damage inspection when necessary. 6.1.3 Design and manufacture 1 equipment according to 5.1.4 ||tt ||6.1.4 Check whether the deep separation equipment and the measuring and controlling equipment are in good working order. 6.1.5 Remove the parts (requires no scale and rust), clean and dry: 6.1. Check whether the gas filling and the gas forming equipment are normal. 6.2 Carbon treatment in the furnace
6.2.1 Loading the furnace
The workpiece is placed in the effective heating zone. The furnace samples and process samples must be loaded. The material grade and process carbon pretreatment conditions are the same as those of the workpiece. The shape and size of the samples can represent the deep carbonization surface of the workpiece. Note: The sample is used as the test sample and the test sample is used as the test sample. The test sample is used as the test sample. The test sample is used as the test sample. The process sample is used as the test sample. 6.2.2 Heating
Control the temperature increase so that there is no obvious temperature difference between the parts of the workpiece. If necessary, the temperature should be increased in stages: 6.2.3 Exhaust
When the temperature rises to 500℃, hydrogen should be passed for protection. The ventilation volume is determined according to the furnace capacity. When the temperature rises to 800℃, turn off the nitrogen and pass the carrier gas until it reaches the deep-layer embedding temperature. 6.2.4 Deep-layer carbonization
High-pressure gas, adjust the gas carbonization pressure to the set value. Determine the deep-layer carbonization protection time according to the technical requirements of the workpiece. 6.2.5 Micro-potential measurement
Magnetic potential measurement can be connected to the on-site conditions and oxygen probe can be used The carbon potential of the steel is measured by the carbon potential determination method, and the control accuracy is proposed according to the requirements of the workpiece. Note: Box compensation method: Put the low carbon steel box 15 degrees: 5:0.05mm, length × width: 100mm × 100mm, original micro content: 0.1%C: into the paint, wait for a long time (it is recommended to be 13m, so that the steel is evenly repaired), take out the brown flush after rapid cold sweep, and use a scale to determine the content of the cavity, which is the furnace atmosphere potential.
6.2.6 Take out the over-temperature sample regularly: check the deep layer rate account situation, and make adjustments. 6.2.7 Cooling
For the requirements of direct quenching of resources 1.For parts, pay attention to temperature uniformity before quenching. When the workpiece is not directly quenched, measures should be taken to prevent or reduce oxidation and decarburization. If necessary, protective gas nitrogen or dripping organic filter should be used for protection. When slow cooling, take appropriate measures to reduce deformation and cracking.
6.3 Floating and tempering
6.3. The heating, cooling and tempering equipment must comply with the provisions of 3.2, 5.3 and 5.4. 6.3.2 If necessary, spheroidization can be carried out before floating. Spheroidization treatment 1. According to the material and specific requirements of the parts, refer to G316923,
JB/T 8929-1499
6.3.3 The heating temperature and holding time of the quenching can be determined according to the material and specific requirements of the parts and can be determined according to GB16924. 3.4 When heating with fire, measures should be taken to prevent oxidation and decarburization. The parts should be refractory in time after refractory treatment. 6.3:5 When testing the carbonization of the parts, pay attention to the temperature uniformity of each part of the parts and the heating and cooling methods of the parts. 6.3.6 The ignition medium should meet the requirements of 5.3.1 and 3.3.2. 6.3. When refractory treatment is carried out, measures should be taken to reduce deformation, prevent cracking of the parts, etc. 4 Follow-up 1. Characters
6.4.1 Clear the residual ignition medium and other materials on the workpiece 6.4.2 Measure the deformation of the workpiece and record it, and straighten it if necessary. 6.4.3 Separate the deep carbonization and tempering quality of the furnace sample and record it. 6.4.4 Anti-rust treatment of the workpiece.
Center 4.5 Arrange all records during the treatment process (temperature, carbonization potential, process inspection and final inspection and necessary matters) 7 Deep carbonization quality inspection
7.1 Materials
Deep carbonization workpieces and furnace samples should comply with the provisions of Chapter 4. 7.1 Appearance quality should comply with the provisions of 6.1.2. 7.3 Surface hardness
3. [Deep magnetic permeation surface hardness unevenness allowable deviation implementation The surface hardness unevenness tolerance shall be in accordance with the provisions of Table 1. The type of workpiece: The carbon hardness unevenness tolerance 1) The local carbon hardness test position should not be at the junction of the carbon and the unpainted. 2) Sub-components refer to parts with special requirements for quality, other than general parts. 5 7.3.1 The deep surface hardness should be measured on the workpiece after the final heat treatment. The measuring disc is selected according to the technical requirements of the workpiece. Different grades can not be measured on the furnace sample. 7.4 Core hardness The core hardness disc position depends on the condition of the workpiece. It can be measured on the workpiece after the final heat treatment. If there are special requirements (or no parts), it can be measured on the core of the furnace sample. 7.5 Measurement of effective hardened layer depth
7.5.1 Generally, the measurement should be carried out on the cross section of the workpiece after final tempering. If there are special requirements (the workpiece cannot be cut), the measurement can be carried out on the cross section of the furnace sample.
7.5.1 The measurement method of effective hardened layer depth should comply with the provisions of 0B/T9450. The unevenness of the effective carburized layer shall not be less than 10%. 7.6 Metallographic structure inspection
7.6. After the workpiece is carbonized, spheroidized, tempered and tempered, the metallographic structure inspection and evaluation can refer to IB.T614!.1 and JB/T6141.3. 7.7 Core mechanical properties: 1. Generally, the core mechanical properties of the parts may not be checked. If there are special requirements, the same material can be pressed into a sample with the same diameter and length of 2m as the part. After anti-seepage treatment, the sample is heated together with the parts to make a standard mechanical properties sample. The tensile strength, strength, length ratio, cross-sectional shrinkage and impact or shaving degree of the sample are measured according to the routine. 7.8 Deformation inspection: After deep filtration and spheroidization treatment, the deformation of the parts can be measured with a micrometer, etc. The content of the measurement can be determined according to the technical requirements of the workpiece. The deformation plate (which can be a deformation plate after calibration) should be within the range of the calibration requirements. 7.9 Crack inspection: Generally, the workpiece is visually inspected for cracks. Important workpieces are inspected for cracks using effective non-destructive detection methods. ID surface decarburization
determined according to GB224
B Safety and environmental protection
should comply with the relevant provisions of food GP15735,
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