This standard specifies the grades, requirements, test methods, inspection rules, markings and quality certificates of ductile iron castings used in the electrical equipment industry. This standard applies to ductile iron castings (hereinafter referred to as ductile iron castings) in the electrical equipment industry. JB/T 4328.10-1999 General Technical Conditions for Ductile Iron Castings for Electrical Equipment JB/T4328.10-1999 Standard download decompression password: www.bzxz.net

JB/T4328.10-1999
This standard is a revision of JB4328.1-86 "General Technical Conditions for Cast Iron Parts for Electrical Equipment". This standard will be implemented from the date of implementation. It also replaces JB4328.1-86. Appendix A of this standard is the appendix of the standard.
This standard is proposed and managed by Shenyang Electrical Equipment Research Institute. This standard is drafted by Shenyang Electrical Equipment Research Institute and Shenyang Electrical Machinery Co., Ltd. The main drafters of this standard are Mi Junfa and Chen Jiashan. This standard was first issued on December 1, 1986, and this standard was revised for the first time. This standard is entrusted to Shenyang Electrical Equipment Research Institute for interpretation. 151
1 Scope
Machinery Industry Standard of the People's Republic of China
Electrician Special Equipment
Nodular Cast Iron General Technical Conditions
Nodular cast iron general requirement forthe electrician special equipmentJB/T4328.10-1999
Replaces JB4328.1-86
This standard specifies the grades, requirements, test methods, inspection rules, markings and quality certificates of ductile iron castings used in the electrician special equipment industry.
This standard applies to ductile iron castings (hereinafter referred to as ductile iron castings) in the electrician special equipment industry. 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/T228--1984Metal tensile test methodGB/T229-1994
Metal Charpy notch impact test method (eqvISO148:1983)GB/T231-1984
Metal Brinell hardness test method
GB/T1348-1988
Ductile iron castings
GB/T5612-1985·Method for indicating cast iron gradesGB/T 9441-1988
JB/T4328.1-1999
3 Requirements
3.1 Grade of ductile iron castings
Metallographic inspection of ductile iron
General technical conditions for grey cast iron castings for special electrical equipment 3.1.1 The grade of ductile iron castings is based on their mechanical properties and the provisions of GB/T5612. 3.1.2 The mechanical properties measured by processing the single cast test block into the test specimen are divided into eight grades (see Table 1 and Table 2). 3.2 Mechanical properties
3.2.1 The mechanical properties of ductile iron parts are based on the mechanical properties specified by the single cast test block. 3.2.2 The mechanical properties of ductile iron parts are based on the two indicators of tensile strength and elongation as the acceptance basis. 3.2.3 When it is necessary to conduct yield strength test, impact test and hardness requirements, the provisions of Article 3.1 shall be implemented. If otherwise specified in the contract, it shall be implemented in accordance with the contract.
3.2.4 If hardness is used as a supply and acceptance indicator, it shall be carried out in accordance with the provisions of Appendix A. 3.3 The chemical composition and metallographic structure of ductile iron parts are generally not used as the basis for acceptance. If metallographic structure inspection is required, it shall be carried out in accordance with the provisions of GB/T9441. The spheroidizing level is generally not less than level 4. Approved by the State Bureau of Machinery Industry on August 6, 1999 152
Implementation on January 1, 2000
JB/T4328.10-1999
The dimensional tolerances of ductile iron parts shall be in accordance with the provisions of Table A1 in Appendix A of JB/T4328.1-1999. Table 1 Brand and mechanical properties of single cast test block
Tensile strength
QT400—18
QT400—15
QT450—10
QT5007
QT600—3
QT700—2
QT800—2
QT900—2
QT400—18
QT400—18L
Cancer service strength
Elongation
Brinell hardness|| tt||130~180
130-180
160~210
170-230
190~270
225~305
245~335
280~360
Impact value of V-notch specimen of single cast test block
Minimum impact value &J/cm2
23±5℃
Average value of three specimens
Note: The letter "L" indicates the impact value of the grade at low temperature. 3.5. Surface quality
Individual value
Metallographic structure
Ferrite
Ferrite
Ferrite+ferrite
Pearlite+ferrite
Pearlite
Pearlite or tempered structure
Bainite or tempered martensite
Average value of three samples
-20 ±2℃
Individual value
3.5.1Under the premise of not affecting the service life and mechanical properties of ductile iron parts, the defects allowed on the non-machined surface are limited to those specified in Table 6 of JB/T4328.1-1999.
3.5.2 Defects on the machined surface are allowed to exist as long as they can be removed by machining. If it cannot be removed, it shall be limited to the provisions of Table 7 in JB/T4328.1-1999 without affecting the mechanical properties and service life. 3.5.3 Defects are not allowed to appear simultaneously on the symmetrical positions on both sides of the same section of the spherical casting. 3.5.4 The residual traces on the surface of the spherical casting shall comply with the provisions of Table 5 in JB/T4328.1-1999. Provisions for repairing casting defects
Before welding repair, the defect must be cleaned until good metal is left, and the area within 30mm from the groove edge and the groove surface shall be cleaned. Repair methods other than welding repair, such as epoxy resin, are allowed for non-important parts. After welding repair, it shall be repaired and processed to meet the surface quality requirements of the casting. After welding repair, aging treatment must be carried out for those that originally require aging treatment. If there is a requirement for air tightness, a leakage test shall be carried out. If there is a requirement for hardness, the hardness difference between it and the parent body shall be within the range of ±20 of the Brinell hardness value. The ductile iron parts after welding repair shall be heat treated to eliminate internal stress. 4 Test methods
4.1 Preparation of test blocks
JB/T4328.10-1999
Single cast test blocks adopt the structural form specified in GB/T1348, and can also be prepared in the furnace according to the provisions of the contract. 4.2 Test specimens
Tensile test specimens are cut from the section line of the single cast test block or the casting body. 4.3 Mechanical property tests
4.3.1 Tensile test
Tensile test shall be carried out in accordance with the provisions of GB/T228. 4.3.2 Impact test
Impact test shall be carried out in accordance with the provisions of GR/T229. 4.3.3 Hardness test
Brinell hardness test shall be carried out in accordance with the provisions of GB/T231. 4.4 Inspection of surface quality of ductile iron parts
4.4.1 The surface quality of ductile iron parts shall be inspected piece by piece by visual inspection. 4.4.2 The size and geometry of ductile iron castings shall be checked piece by piece as specified in the drawings. 5 Inspection rules
5.1 When inspecting the tensile strength or impact value, first use one tensile test specimen or a group (3) of impact test specimens for testing. If the test results meet the requirements, the batch of castings is qualified. If the test results do not meet the requirements, repeat the test with double the same batch of specimens. 5.2 When the repeated test results can all meet the requirements, the batch of castings is qualified. If 1/2 of the double repeated tests do not meet the requirements, the batch of castings is unqualified.
Marking and quality certificate
6.1 Ductile iron castings should have the manufacturer's mark.
6.2· Ductile iron castings shall be accompanied by a quality certificate signed by the inspection department before leaving the factory, which shall indicate: a) manufacturer name or code:
b) part name, drawing code and quantity: c) brand (important castings shall indicate the furnace number); d) various inspection results;
e) standard number.
hardness brand
JB/T4328.10-1999
Appendix A
(Appendix to the standard)Www.bzxZ.net
Hardness of ductile iron castings
Under special circumstances, with the agreement of both the supplier and the buyer, it is allowed to specify the hardness grade of ductile iron according to the hardness value measured on the casting body. This appendix divides ductile iron castings into 8 grades according to their hardness, see Table A1. Table A1 Hardness of ductile iron castings
Mechanical properties (for reference)
Hardness grade
QT—H330
QT—H300
QTH265
QT—H230
QT-H200
QT-H185
QT-HI55
QT—H150
A2 Requirements
A2.1 Hardness
280-360
245~335
225~305
190~270
1 70-230
160-210
130-180
130-180
Metallographic structure
Bainite or tempered martensite
Pearlite or tempered structure
Pearlite
Pearlite + ferrite
Ferrite + pearlite
Ferrite
Ferrite
Tensile strength
Yield strength o2
Minimum value
, Each batch of castings must be tested for hardness. While testing the hardness value, the metallographic structure must be tested. A2.2 Metallographic structure
Elongation
The metallographic structure shall comply with the provisions of GB/T9441. The spheroidization level shall generally not be lower than level 4. The inspection frequency and sampling requirements shall be agreed upon by the supply and demand parties.
The spheroidization level and matrix structure can be inspected by non-destructive testing methods. In case of dispute, the metallographic inspection method shall be used for arbitration. Test method
The hardness test can be carried out in accordance with the requirements of GB/T231. If the hardness cannot be measured on the casting body, the hardness can be measured on the test block attached to the casting after agreement between the supply and demand parties. The structural type of the cast hardness test block attached to the casting is shown in Figure A1. 155
JB/T4328.101999
A3.3 When heat treatment is required, the hardness test block shall be removed from the casting after heat treatment. 156
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