Some standard content:
JB/T4403
-1999
Previous
Preface
This standard is a revision of JB4403
, 87 "Graphite Cast Iron Parts". During the revision, editorial changes were made to the original standard, and the main technical content remained unchanged.
This standard will replace JB4403 from the date of implementation. Appendix A of this standard is a standard appendix
87
Appendix B and Appendix C of this standard are both reminder appendices. This standard is proposed and administered by the National Casting Standardization Technical Committee. This standard was drafted by: Zhengzhou Machinery Research Institute, etc. The main drafters of this standard are: Zhang Zhongji, Ji Yuan, etc. 392
1 Scope
Machinery Industry Standard of the People's Republic of China
Vermicular graphite iron castings
Vermicular graphite iron castingsJB/T 4403---1999
Replaced JB4403--87
This standard specifies the product grades, technical requirements, test methods, inspection rules, markings and certificates of conformity for compacted graphite iron castings. This standard applies to ordinary and low-alloy compacted graphite iron castings cast in sand molds or molds with cooling effects equivalent to sand molds. Other casting molds can be used as a reference.
2 Reference standards
The provisions contained in the following standards constitute provisions of this standard by being quoted in this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties using this standard should explore the possibility of using the latest version of the standard listed below. GB/T2281987 Metal Tensile Test Method
G13/T231--1984 Metal Brinell Hardness Test Method GB/T5612-·1985 Cast Iron Grade Representation Method GB/T6060.1--1997 Surface Roughness Comparison Sample Casting Surface
GB/T6414-1986 Dimensional tolerance of castings
J13/T3829—1999
Metallography of flat graphite cast iron
3 Product grades
This standard is based on The tensile strength of single-cast test blocks is divided into five grades according to the provisions of GB/T5612, see Table 1 Table 1
Tensile strength h
No.
Brand|| tt||RuT420
RuT380
RuT340)
RuT300
RuT260
4
Technical requirements
MPa|| tt||420
380
340
300
260
yield strength.3
MPa
not less than
335
300
270
240
195
Grade of compacted graphite iron
Elongation|| tt||%
0.75
0.75
1.0
1.5
hardness value range
HB
200~280
193~274
170~249
140--217
121～197
Vermicularization rate V;
Main matrix Organization
not less than
pearlite
pearlite
50
pearlite! Ferrite | | tt | , the additional acceptance rate was approved by the National Machinery Industry Bureau on 1999-06-24 and implemented on 2001.01-01
393
JB/T 4403 -1999
. If the party has requirements for other performance, it can be accepted according to Table 1. 4.2 The creep rate of graphite in the metallographic structure of castings is generally accepted according to the provisions of Table 1. However, according to the different uses and characteristics of castings, the creep rate can meet specific requirements after negotiation between the supply and demand parties. 4.3 The mechanical properties of spiral graphite iron castings can be achieved through heat treatment. 4.4 Remove casters, mud cores, sticky sand, flash and scabs from the castings. 4.5 The surface roughness of the castings shall be inspected according to the provisions of 13/T6060.1 and the grade agreed upon by the supply and demand hall. 4.6 The size and F tolerance of the castings shall comply with the provisions of (B/T6114). It may also be in accordance with the provisions of the drawing or ordering technical requirements. Execution 4.7 Castings are not allowed to have defects that affect machining and performance of parts. The shape, quantity, size and location of allowed defects, as well as whether they can be repaired and the method of repair, should be stipulated in the ordering conditions. 5. Method
5.1 The standard test block used in the tensile test is shown in Figure 1. Generally, type 1 in Table 2 should be preferred. After negotiation between the supplier and the buyer, other types in Table 2 or Appendix A (standard filling) can also be used. (Appendix of the appendix) of the test block, or use other verified test blocks. The test block should be cast in the same molten iron as the casting, and should be taken from the late casting stage.
The boxing temperature of the test block should not be higher than 500 (.|| tt||For castings that require heat treatment, the test block should be agreed upon by the casting manufacturer. The furnace heat treatment allows the use of an attached cast test block or a test block cut directly from the casting. The acceptance index shall be agreed between the supplier and the buyer. The attached cast test block is shown in Figure 2, attached. The casting test block ruler is shown in Table 3
H
Figure 1 Y-type single-cast test block
Y-type single-cast test block size and sand consumption
Table 2| |tt||Test block type
1
E
TV
394
12
25
50| |tt||75
V
10
55
100
125
test block
foot|| tt||x
25
40
50
65
Wo
Y
135||tt| |t.
140
150
175
7
Determined by tensile
sample
|| tt||mm
Block
Minimum sanding belt
31
Casting wall thickness
>30～60
>60~ 200
Lu Cheng
40
70
JB/T 4403
1999
pieces
t||tt ||Figure 2 Attached cast test block
Table 3 Attached cast test block size
Test
bhmin
30
52.5
If smaller sizes are used, the following relationship should be met: 1
h=0.75a,c=a/2.
block
C tmin
20|| tt||35
foot
inch
10 or 60
70 or 105
2 When the weight of the piece is equal to or greater than 2000kg, the wall thickness is When the diameter is between 30 and 200mm, the attached cast test block should generally be used. 3 The recommended total length I=180mm can be appropriately reduced under special circumstances, but shall not be less than 125mm. 5.2 The dimensions of the tensile specimen are shown in Figure 3.
Φ20
Note
60* years
70
L.
.
1Lu is the original gauge length, Here Ln=5d; d is the original diameter of the sample. (When using "type test block, d can be appropriately small). 2L is the length of the parallel section, >a-generally L-Id). 3 is the total length of the sample, determined by I and I.
1.6
R20
Figure 3 Tensile specimen
The rest 6.3／
Imm
180
180
5.3 tension The tensile test is carried out in accordance with GB/T228
5.4 The hardness is measured on the test block according to the requirements of GB/T231. If there are special requirements, it can be measured on the specified part of the casting according to the agreement between the supplier and the buyer. |tt||The creep rate and matrix structure of 5.5 vermicular graphite cast iron are evaluated in accordance with JB/T3829, and the metallographic samples are taken from the mechanical property test blocks. 395
6 Inspection Rules
6.1 Batch division:
JB/T4403-1999
a) For single-piece, small-batch production, castings poured by hot metal or single castings weighing more than 2000kg are batches: b) For mass production, under quality assurance inspection measures, the weight of castings is 2000kg as a batch; c) For mass production, under continuous observation of the metallographic or fracture conditions of the sample in front of the furnace, the maximum weight of each batch can be Relax. The limit is within the output of the melting furnace for 2 hours.
6.2 The first batch of castings and important castings should be inspected for size and geometry on each casting. General castings can be randomly inspected - the spot inspection method can be carried out according to the agreement between the supplier and the buyer.
6.3 The appearance quality of castings shall be inspected piece by piece. The surface roughness of castings is randomly inspected. 6.4 Take a tensile specimen from each batch of castings, do a tensile test and check the creep rate. If it meets the requirements, the batch of castings is qualified, otherwise the batch of castings is unqualified
If the creep rate is qualified, the tensile test If the tensile test results do not meet the requirements, you can take two more samples from the same batch and conduct repeated tests. If the repeated test results meet the requirements, the batch of castings is qualified; if the repeated test results still have one sample that does not meet the requirements. If the requirements are met, the batch of castings will be unqualified. If the tensile test results meet the requirements but the creep rate does not meet the requirements, it is allowed to check the creep rate of the cast body of the batch of powdered bacteria. If it meets the requirements, the batch of castings will be qualified.
If there is no spare sample, with the consent of the purchaser, a sample can be cut from the casting body and re-tested or the conversion rate can be checked at an appropriate location. If the conversion rate is qualified, the casting is deemed to be qualified.
6.5 Tensile test If the test results do not meet the requirements due to the following circumstances, the test will be invalid: a) The sample is improperly installed on the testing machine, or the testing machine is operated improperly: b) The sample is poorly processed; || tt||c) The tensile sample broke outside the gauge length;
d) The fracture surface of the sample has casting defects.
7 Marks and Certificates of Conformity
7.1 Castings that have passed the inspection shall have the mark of the supplier's technical inspection department, and the mark shall be placed on the non-machined surface of the casting. 7.2 Castings leaving the factory should be accompanied by a certificate that conforms to this standard, with the following content: a) Manufacturing name;
b) Casting drawing number and casting quantity;
c) Casting material grade; ||tt| |d) Casting batch number and heat;
e) Test results;
f) This standard number.
396
Test block type
Ia
Ib
t
12
25
25
50
75
R5
R5
JB/T4403—1999
Appendix A
(standard appendix )
W-type single cast test block
Test block types: I-type, Ia-type, I-type and V-type solution ~
Slope
3″| |tt||Type Ib
Figure AlbZxz.net
Table A1
Test
Block
National ruler
x
40
55
90
90
125
30
40
40
60| |tt||65
y
80
100
100
150
165
2||tt ||Determined by tensile specimen
Test
mm
Block
The smallest sand is the most
30
40||tt ||80
397
Brand
No.
RuT420
RuT380
RuT340
RuT300
Rur260 | tt | Parts with high wear resistance have higher strength and hardness, and have higher wear resistance and thermal conductivity. They are suitable for manufacturing parts that require higher strength, stiffness and wear resistance
Moderate strength and hardness, with a certain degree of wear resistance. Plastic toughness, high thermal conductivity, good density, suitable for manufacturing parts that require higher strength and withstand thermal fatigue
Average strength, low hardness, high plastic toughness and thermal conductivity, general castings It requires annealing heat treatment and is suitable for manufacturing parts that can withstand impact loads and thermal fatigue
Appendix C
Application Examples
Piston rings, cylinder liners, brake discs, glass molds, brakes Drums, valve bead grinding discs, silt suction pump bodies, etc.
Heavy machine tool parts with guide rail surfaces, large gantry milling beams, large gear boxes, covers, seats, brake drums, flywheels, glass molds, crane drums , sintering machine slides, etc.
Exhaust pipes, gearbox bodies, cylinder heads, textile machine parts, hydraulic parts, steel ingot molds, some small sintering machine grates and other supercharger exhaust gas intake casings, automobiles, Certain chassis parts of tractors, etc.
(Appendix of prompts)
Explanation on the wall thickness sensitivity and creep decay of compacted graphite cast iron The grades of compacted graphite cast iron in Table 1 of this standard are specified Mechanical property indicators refer to the mechanical properties of standard single-cast test blocks, and they represent the mechanical properties of castings whose cooling rates are equivalent. Although the wall thickness sensitivity of compacted graphite iron is much smaller than that of gray iron and smaller than that of ductile iron, there is still a certain wall thickness sensitivity. A single cast test block cannot fully represent the mechanical properties and metallographic structure of castings with different thickness and thin sections. Therefore, the precise quantitative relationship between the mechanical properties of single-cast test blocks and castings with different wall thicknesses should be obtained through experiments. It is worth noting that the proportion of ductile graphite in the metallographic structure of thin-walled vermicular iron parts will increase, and its creep rate will be higher than the low-surface tensile strength of standard single-cast test blocks; the tensile strength of thick and large-section vermicular iron parts The creep rate will be increased and the tensile strength will be reduced compared with the standard single cast test block. In addition, vermicular graphite cast iron still needs to pay attention to the creep decay property. After the chemical treatment is completed, the possibility of creep decay within ten minutes is generally very small. However, if thick castings are poured, when the type 1 single-cast test block has a higher chemical rate, pouring and pouring by Ding If the post-solidification time is long, the body of the piece may deteriorate into gray cast iron. For this reason, when producing thick vermicular iron parts, attached cast test blocks should be used, or attached cast metallographic test blocks should be set up for inspection while pouring single cast test blocks.
398
2 Castings leaving the factory should be accompanied by a certificate that complies with this standard, with the following content: a) Manufacturing name;
b) Casting drawing number and casting quantity;
c) Casting material grade; ||tt| |d) Casting batch number and heat;
e) Test results;
f) This standard number.
396
Test block type
Ia
Ib
t
12
25
25
50
75
R5
R5
JB/T4403—1999
Appendix A
(standard appendix )
W-type single cast test block
Test block types: I-type, Ia-type, I-type and V-type solution ~
Slope
3″| |tt||Type Ib
Figure Al
Table A1
Test
Block
National ruler
x
40
55
90
90
125
30
40
40
60| |tt||65
y
80
100
100
150
165
2||tt ||Determined by tensile specimen
Test
mm
Block
The smallest sand is the most
30
40||tt ||80
397
Brand
No.
RuT420
RuT380
RuT340
RuT300
Rur260 | tt | Parts with high wear resistance have higher strength and hardness, and have higher wear resistance and thermal conductivity. They are suitable for manufacturing parts that require higher strength, stiffness and wear resistance
Moderate strength and hardness, with a certain degree of wear resistance. Plastic toughness, high thermal conductivity, good density, suitable for manufacturing parts that require higher strength and withstand thermal fatigue
Average strength, low hardness, high plastic toughness and thermal conductivity, general castings It requires annealing heat treatment and is suitable for manufacturing parts that can withstand impact loads and thermal fatigue
Appendix C
Application examples
Piston rings, cylinder liners, brake discs, glass molds, brakes Drums, valve bead grinding discs, silt suction pump bodies, etc.
Heavy machine tool parts with guide rail surfaces, large gantry milling beams, large gear boxes, covers, seats, brake drums, flywheels, glass molds, crane drums , sintering machine slides, etc.
Exhaust pipes, gearbox bodies, cylinder heads, textile machine parts, hydraulic parts, steel ingot molds, some small sintering machine grates and other supercharger exhaust gas intake casings, automobiles, Certain chassis parts of tractors, etc.
(Appendix of prompts)
Explanation on the wall thickness sensitivity and creep decay of compacted graphite cast iron The grades of compacted graphite cast iron in Table 1 of this standard are specified Mechanical property indicators refer to the mechanical properties of standard single-cast test blocks, and they represent the mechanical properties of castings whose cooling rates are equivalent. Although the wall thickness sensitivity of compacted graphite cast iron is much smaller than that of gray iron and smaller than that of ductile iron, there is still a certain wall thickness sensitivity. A single cast test block cannot fully represent the mechanical properties and metallographic structure of castings with different thickness and thin sections. Therefore, the precise quantitative relationship between the mechanical properties of single-cast test blocks and castings with different wall thicknesses should be obtained through experiments. It is worth noting that due to the increase in the proportion of ductile graphite in the metallographic structure of thin-walled vermicular iron parts, its creep rate will be higher than the low-surface tensile strength of standard single-cast test blocks; the tensile strength of thick and large-section vermicular iron parts The creep rate will be increased and the tensile strength will be reduced compared with the standard single cast test block. In addition, vermicular graphite cast iron still needs to pay attention to the creep decay property. After the chemical treatment is completed, the possibility of creep deterioration within ten minutes is generally very small. However, if thick castings are cast, when the type 1 single-cast test block has a higher chemical rate, pouring and pouring by Ding If the post-solidification time is long, the body of the piece may deteriorate into gray cast iron. For this reason, when producing thick vermicular iron parts, attached cast test blocks should be used, or attached cast metallographic test blocks should be set up for inspection while pouring single cast test blocks.
398
2 Castings leaving the factory should be accompanied by a certificate that complies with this standard, with the following content: a) Manufacturing name;
b) Casting drawing number and casting quantity;
c) Casting material grade; ||tt| |d) Casting batch number and heat;
e) Test results;
f) This standard number.
396
Test block type
Ia
Ib
t
12
25
25
50
75
R5
R5
JB/T4403—1999
Appendix A
(standard appendix )
W-type single cast test block
Test block types: I-type, Ia-type, I-type and V-type solution ~
Slope
3″| |tt||Type Ib
Figure Al
Table A1
Test
Block
National ruler
x
40
55
90
90
125
30
40
40
60| |tt||65
y
80
100
100
150
165
2||tt ||Determined by tensile specimen
Test
mm
Block
The smallest sand is the most
30
40||tt ||80
397
Brand
No.
RuT420
RuT380
RuT340
RuT300
Rur260 | tt | Parts with high wear resistance have higher strength and hardness, and have higher wear resistance and thermal conductivity. They are suitable for manufacturing parts that require higher strength, stiffness and wear resistance
Moderate strength and hardness, with a certain degree of wear resistance. Plastic toughness, high thermal conductivity, good density, suitable for manufacturing parts that require higher strength and withstand thermal fatigue
Average strength, low hardness, high plastic toughness and thermal conductivity, general castings It requires annealing heat treatment and is suitable for manufacturing parts that can withstand impact loads and thermal fatigue
Appendix C
Application Examples
Piston rings, cylinder liners, brake discs, glass molds, brakes Drums, valve bead grinding discs, silt suction pump bodies, etc.
Heavy machine tool parts with guide rail surfaces, large gantry milling beams, large gear boxes, covers, seats, brake drums, flywheels, glass molds, crane drums , sintering machine slides, etc.
Exhaust pipes, gearbox bodies, cylinder heads, textile machine parts, hydraulic parts, steel ingot molds, some small sintering machine grates and other supercharger exhaust gas intake casings, automobiles, Certain chassis parts of tractors, etc.
(Appendix of prompts)
Explanation on the wall thickness sensitivity and creep decay of compacted graphite cast iron The grades of compacted graphite cast iron in Table 1 of this standard are specified Mechanical property indicators refer to the mechanical properties of standard single-cast test blocks, and they represent the mechanical properties of castings whose cooling rates are equivalent. Although the wall thickness sensitivity of compacted graphite iron is much smaller than that of gray iron and smaller than that of ductile iron, there is still a certain wall thickness sensitivity. A single cast test block cannot fully represent the mechanical properties and metallographic structure of castings with different thickness and thin sections. Therefore, the precise quantitative relationship between the mechanical properties of single-cast test blocks and castings with different wall thicknesses should be obtained through experiments. It is worth noting that the proportion of ductile graphite in the metallographic structure of thin-walled vermicular iron parts will increase, and its creep rate will be higher than the low-surface tensile strength of standard single-cast test blocks; the tensile strength of thick and large-section vermicular iron parts The creep rate will be increased and the tensile strength will be reduced compared with the standard single cast test block. In addition, vermicular graphite cast iron still needs to pay attention to the creep decay property. After the chemical treatment is completed, the possibility of creep decay within ten minutes is generally very small. However, if thick castings are poured, when the type 1 single-cast test block has a higher chemical rate, pouring and pouring by Ding If the post-solidification time is long, the body of the piece may deteriorate into gray cast iron. For this reason, when producing thick vermicular iron parts, attached cast test blocks should be used, or attached cast metallographic test blocks should be set up for inspection while pouring single cast test blocks.
398
4403-1999
Appendix B
(prompt appendix)
Performance characteristics and application examples of various grades of spiral graphite cast iron Table B1
Performance characteristics||tt| |High strength, high hardness, high wear resistance and high thermal conductivity. The casting material needs to be added with alloy elements or normalized heat treatment. It is suitable for manufacturing parts that require high strength or high wear resistance. The strength and hardness are relatively high. High, with high wear resistance and thermal conductivity. Suitable for manufacturing parts that require higher strength, stiffness and wear resistance
Moderate strength and hardness, certain plastic toughness, high thermal conductivity, and good density. Suitable for manufacturing parts that require higher strength and withstand Thermal fatigue parts
have average strength, low hardness, high plastic toughness and thermal conductivity. Castings generally require annealing heat treatment, and are suitable for manufacturing parts that can withstand impact load and thermal fatigue
Appendix C
Application examples
Piston rings, cylinder liners, brake discs, glass molds, brake drums, valve bead grinding discs, silt suction pump bodies, etc.
Heavy duty with guide surface Machine tool parts, large gantry milling beams, large gear boxes, covers, seats, brake drums, flywheels, glass molds, crane drums, sintering machine slides, etc.
Exhaust pipes, gearbox bodies, cylinder heads, textiles Machine parts, hydraulic parts, steel ingot molds, some small sintering machine grates and other supercharger exhaust gas inlet casings, some chassis parts of cars and tractors, etc.
(Appendix to the prompt)
Explanation on the wall thickness sensitivity and creep decay properties of compacted graphite cast iron. The mechanical performance indicators specified for the grades of compacted graphite cast iron in Table 1 of this standard refer to the mechanical properties of standard single-cast test blocks. They represent the cooling properties of the compacted graphite cast iron. Although the wall thickness sensitivity of vermicular graphite cast iron is much smaller than that of gray iron and ductile iron, there is still a certain wall thickness sensitivity, and a single cast test block cannot fully represent castings with different thicknesses and thin sections. Therefore, the precise quantitative relationship between the mechanical properties of single-cast test blocks and castings with different wall thicknesses should be obtained through experiments. It is worth noting that the metallographic structure of thin-walled vermicular iron parts will be due to ductility. As the proportion increases, the creep rate will be higher than the low-surface tensile strength of the standard single-cast test block; the creep rate of thick and large-section vermicular iron parts will be higher than the standard single-cast test block, but the tensile strength will be lower. . In addition, vermicular graphite cast iron still needs to pay attention to the creep decay. After the casting treatment is completed, the possibility of creep decay within ten minutes is generally very small, but if thick castings are cast, when the type 1 is single. When the casting test block has a high conversion rate, the solidification time after pouring and pouring is long, and the body of the piece may deteriorate into gray cast iron. For this reason, when producing thick vermicular iron parts, attached casting test blocks should be used, or the casting unit should be used. The cast test block is also equipped with a cast metallographic test block for inspection
398
4403-1999
Appendix B
(prompt appendix)
Performance characteristics and application examples of various grades of spiral graphite cast iron Table B1
Performance characteristics||tt| |High strength, high hardness, high wear resistance and high thermal conductivity. The casting material needs to be added with alloy elements or normalized heat treatment. It is suitable for manufacturing parts that require high strength or high wear resistance. The strength and hardness are relatively high. High, with high wear resistance and thermal conductivity. Suitable for manufacturing parts that require higher strength, stiffness and wear resistance
Moderate strength and hardness, certain plastic toughness, high thermal conductivity, and good density. Suitable for manufacturing parts that require higher strength and withstand Thermal fatigue parts
have average strength, low hardness, high plastic toughness and thermal conductivity. Castings generally require annealing heat treatment and are suitable for manufacturing parts that can withstand impact load and thermal fatigue
Appendix C
Application examples
Piston rings, cylinder liners, brake discs, glass molds, brake drums, valve bead grinding discs, silt suction pump bodies, etc.
Heavy duty with guide surface Machine tool parts, large gantry milling beams, large gear boxes, covers, seats, brake drums, flywheels, glass molds, crane drums, sintering machine slides, etc.
Exhaust pipes, gearbox bodies, cylinder heads, textiles Machine parts, hydraulic parts, steel ingot molds, some small sintering machine grates and other supercharger exhaust gas inlet casings, some chassis parts of cars and tractors, etc.
(Appendix to the prompt)
Explanation on the wall thickness sensitivity and creep decay properties of compacted graphite cast iron. The mechanical performance indicators specified for the grades of compacted graphite cast iron in Table 1 of this standard refer to the mechanical properties of standard single-cast test blocks. They represent the cooling properties of the compacted graphite cast iron. Although the wall thickness sensitivity of vermicular graphite cast iron is much smaller than that of gray iron and ductile iron, there is still a certain wall thickness sensitivity, and a single cast test block cannot fully represent castings with different thicknesses and thin sections. Therefore, the precise quantitative relationship between the mechanical properties of single-cast test blocks and castings with different wall thicknesses should be obtained through experiments. It is worth noting that the metallographic structure of thin-walled vermicular iron parts will be due to ductility. As the proportion increases, the creep rate will be higher than the low-surface tensile strength of the standard single-cast test block; the creep rate of thick and large-section vermicular iron parts will be higher than the standard single-cast test block, but the tensile strength will be lower. . In addition, vermicular graphite cast iron still needs to pay attention to the creep decay. After the casting treatment is completed, the possibility of creep decay within ten minutes is generally very small, but if thick castings are cast, when the type 1 is single. When the casting test block has a high conversion rate, the solidification time after pouring and pouring is long, and the body of the piece may deteriorate into gray cast iron. For this reason, when producing thick vermicular iron parts, attached casting test blocks should be used, or the casting unit should be used. The cast test block is also equipped with a cast metallographic test block for inspection
398
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