JB/T 5000.8-1998 General technical conditions for heavy machinery forgings
Some standard content:
JB/T5000.8—1998
Foreword
This standard is proposed and managed by the Deyang Large Castings and Forgings Research Institute of the Ministry of Machinery Industry. The drafting units of this standard are: Qiqihar Casting, Forging and Welding Research Institute, Deyang Large Castings and Forgings Research Institute. The main drafters of this standard are: Song Leigou, Lv Yuheng, Qi Pinzhi, Song Shidan. 253
1 Scope
Machinery Industry Standards of the People's Republic of China
General Technical Conditions for Heavy Machinery
Forgings
The heavy mechanical general techniques and standardsForging
JB/T5000.8-1998
This standard specifies the technical requirements, inspection rules, test methods, quality certificates and marks for large forgings for general purposes. This standard applies to the ordering, manufacturing and inspection of large forgings of carbon steel and alloy structural steel forged by hydraulic presses and forging hammers. 2 Reference Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, 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 subtitles. GB223—82~~94 Chemical analysis methods for steel and alloys GB226--77 Acid etching test method for macrostructure and defects of steel GB 228—871
Metal tensile test method
GB229—94 Metal Charpy notch impact test method GB231··84 Metal Brinell hardness test method GB1979—80 Structural steel macrostructure defect rating chart GB/T4338--1995 High temperature tensile test of metallic materials GB6394-86 Determination of average grain size of metals GB/T6402-~91 Ultrasonic inspection method for steel forgings GB10561--·89 Microscopic evaluation method for non-metallic inclusions in steel 3 Ordering requirements
3.1 The purchaser shall specify the standard adopted for forgings, forging group, steel grade, corresponding technical requirements and inspection items in the order contract or drawings. And other additional instructions.
3.2 The purchaser shall provide order drawings.
3.3 When the purchaser has additional requirements, it shall be agreed upon by both parties. 4 Technical requirements
4.1 Manufacturing process
4.1.1 Refining
If the purchaser has no special requirements, the smelting method shall be determined by the supplier. 4.1.2 Forging
4.1.2.1 The nozzle and riser of each steel ingot shall have sufficient removal to ensure that the forging has no shrinkage cavity and severe segregation. Approved by the State Bureau of Machinery Industry on September 30, 1998 254
Implementation on December 1, 1998
JB/T5000.8—1998
4.7.2.2 Forgings shall be forged on a forging press with sufficient capacity to ensure that the interior of the forging is fully forged. 4.1.2.3 When forging with steel ingots, the forging ratio is generally not less than 3 for those that have not been roughened; the forging ratio is not less than 2.5 for those that have been roughened. The forging ratio of the flange part is not less than 1.7. When advanced forging methods are used, the forging ratio shall comply with the corresponding regulations. 4.7.2.4 When forging with forged or rolled materials, the forging ratio is generally not less than 1.5, and the forging ratio of the flange is not less than 1.34.1.2.5 After forging, the forgings shall be cooled or heat treated in a certain way to prevent damage to the forgings and have good mechanical processing properties. 4.1.3 Heat treatment
The final heat treatment of forgings shall be carried out according to the delivery status specified in the order contract or drawing. 4.1.4 Machining
The machining of forgings shall comply with the dimensions and surface roughness specified in the order drawing. 4.2 Chemical composition
The chemical composition of steel shall comply with the provisions of the standard specified in the order contract or drawing. 4.3 Mechanical properties
The mechanical properties of forgings shall comply with the provisions of the specified standards or drawings. 4.4 When the purchaser deems it necessary, the inspection methods and acceptance criteria for flaw detection, high temperature strength, low temperature toughness, grain size, inclusions, metallographic structure and other supplementary requirements may be proposed and determined by negotiation between the supply and demand parties. 5 Inspection rules and test methods
5.1 Chemical composition analysis
5.1.1 Melting analysis
5.1.1.1 Sampling and analysis should be carried out when each furnace (package) of molten steel is poured. For large ingots cast from multiple furnaces, the results of the weight method should be reported. 5.1.1.2 If the sampling or test does not meet the requirements, alternative specimens can be taken from appropriate parts near the surface of the ingot or forging. 5.1.2 Finished product analysis
If the purchaser requests, samples can be taken from the forgings for finished product analysis. Disks or other solid parts are taken from any point between half the radius and the outer diameter, and hollow parts or rings are taken from halfway between the inner and outer surfaces, or from the mechanical properties test specimen. Product analysis can replace smelting analysis. The allowable deviation of product analysis for specified elements is in accordance with Table 1 or Table 2. Table 1 Allowable deviation of chemical composition of ordinary carbon steel and low alloy steel products Composition range
Element
C
Mn
Si
S
Note
%
50.80
>0.80
0.35
>0.35
0.050
0.050
650
+0.021(0. 032*)
0.02
-0.03
10.05
0.08
1-0.10
+0.03
±0.05
+0.005
-0.005
Section
Surface
cn
Area
0 11 300-~2 6001>2 600~-5 200 5 200--10 400>650~-1 300
0.04
±0.05
±0.10
±0.03
±0.05
+0.005
:-0.005
±0.04
±0.05
±0.11
±0.04
±0.06
+0.005
+0.008
±0.05
±0.06
: 0. 12
±0.01
±0.07
+0.005
+0.008
Cross-sectional area refers to the maximum cross-sectional area of ??the forging before rough processing (excluding the center hole) 2 Composition range refers to the composition range of the steel grade specified for the forging, 1) 0.02 is applicable to low alloy steel.
2) Applicable to ordinary carbon structural steel.
±0.a6
=0.07
三0.12
±0.05
+o.07
-+0.006
0.010
%
10400
±0.06
± 0.08
. 0.13
0.06
±0.09
+-0.006
+0.015
255
Elements
C
Si
Mn
P
s
Cr
Ni
Mo
V
Nb
T
w
Al
Specified chemical
Composition range
%
50.25
>0.25~~0. 50
20.50
0.33
>0.35
0.90
>0.90
0.050
0.030
20.030
0.90
>0.90~2.10
2. 10~10. 00
1.00
1. 00~2. 00
2. 00~-5. 30
s0.20
20. 20~0. 40
20.40-~1.15
≤0.10
>0.10~~0.25
>0.25~0.50
0.14
≥0. 14-0. 50
≤0.85
1.00
>1. 00~4. 00.分分安全可以截
650
±0.03
±0.02
±0. 05
±0.03
±0.06
+0.008
+0.005
-+0.010
±0.03
± 0.05
±0.10
±0.03
±0.05
±0.07
±0.01
±0.02
±0 . 03
±0.01
±0.02
±0.03
±0.02
±0.06
±0.05
±0.05
±0.09
±0.05
±0.10
面
cm2
进
≥1300～26002600~5200 >5200~104200>650~1 300
±0.03
±0.04
±0.05
±0.03
二0.06
± 0.04
+:0.06
+0.008
+0.005
0.010
±0.04
±0.06
±0.10
±0.03
+0.05
±0.07
±0. 02
±0.03
±0.04
±0.01
±0.02
±0.03
±.02
± 0.06
±0. 05
+0.05
±0.09
±0.05
±0.10
5.1.3 动学分分分品核持按GB223。5.2力学模式方法|| tt. ||±0.05
±0.07
-—0.010
+0.005
-t 0. 010
±0.04
±0.06
±:0.10
±0.03
±0.05
±0.07
±0.02
±0.03
±0.05
±0.01
±0.02
±0.03
±0.02
±0. 06
±0.05
±0.05
±0.10
0.06
±:0.10
上0.04
+ 0.05
±0.06
±0.04
+0.07
±0.06
±0.08
+0.010
0.005|| tt||+0.010
± 0. 05
0.07
±0.14
±0.03
±0.05
±0.07|| tt||±0.02
±0.03
±0.06
±0.01
±0.02
±0.03
±0.02||tt ||±0.06
生0.05
±0.f
±0.12
1.0.07
±0.12
0.05|| tt||0. 06
± 0. 07
±:0.05
±0.07
±0.07
±0.08
--0.015||tt ||+0.005
-0.015
0.05
±0.07
=0.15
±0.03
+0.05
±0.07
±0.03
±0.04
0. 07
±0.01
上0. 02
±0.03
±0.03
±0.07
±0.05
±0.06
-+:0. 12
￥0.07
±0.12
足件的力学设计设计地地和取样分地按震方选定的足件组别安全。见表3。256
2-104 200
±0.05
1.0.06
±0.07
上0.06
±0.09
10.08||tt| |+0.09
-+0.015
0.006
-0.015
±0. 06
.1- 0. 08
t0.16
±0.03
0.05
±0.07
0.03||tt| |±0.04
+0.08
0.01
±0.02
t0.03
±0.03
-.0. 08||h||0.05||h||0. 07
±.14
:0.08
0.14
足亶
电影
电视地地
不电视|| tt||HB
HB
a,(as.a)
Ak
HB
a(as.2)
α
Ak
HB
5.2.2 トリーム炮体
组批计生
JB/T 5000.8 -1998
表3身件水收频学
力学言件
同钢号，问热电视
炉饮. 发明发动在了
或相近的身亶
单件||tt ||机设计
抽
硬
度
每柉时间5%%,但全部于5件，
使用身件开件差不二手40HB。
同批身性图工差不身50
HB，电视件了全机-处.每处溔
3点。 身件于长或发动可以，则在超件的头、尾、主件各气-处
每件均受性感，图像差不这些
40HB，每处昺3点，每件了长或
家天，在头，尾和结果各气
处
每柉抽没水水2%,但不得少
同钢号，同热电视
炉次，同发了件光京
或相近的运亶
单件
于2亶，同-运亶只有组试
样，即1个了了，2个语方有电视设计时下载设计试样数
量
每件均受设计，Take a group of 试样即
1个试方，2个机。圀方有特格设计时，可以件试样水水
每性均受性性，图像差不性了
10HB，每处明3点.身件记长或
Complex shape，在头.The tail and the middle shall be measured at
(for reference)
Each piece shall be inspected, and the hardness difference shall not exceed
40HB. 3 points shall be measured at each place. For forgings that are long or
complicated in shape, the head, tail and middle shall be measured at each place. Forgings shall be sampled at the sufficiently extended, elevated or enlarged part equivalent to the riser end of the ingot. The sampling position is shown in Figure 15.2.2.1 The sample of solid shaft forgings shall be taken at a radius of one-third from the surface. For square and rectangular forgings, it shall be taken from the cross-section diagonal at one-sixth of the angle vertex. See Figure 1a). 5.2.2.2 The sample of hollow forgings shall be taken at half the wall thickness. See Figure 1b). 5.2.2.3 When sampling at the enlarged outer diameter part of the disc forging, the sample shall be taken at half the height of the enlarged part; when sampling at the elevated part, the sample shall be taken from one-third of the radius from the outer edge. See Figure 1c). 5.2.2.4 When sampling the ring forgings at the added part, the sample should be taken at half the height; when sampling the heightened part, the sample should be taken at half the wall thickness. See Figure 1d).
5.2.3 Sampling direction
5.2.3.1 For shafts, cylinders and forgings with mainly lengthening deformation, the tensile and impact specimens shall be taken in the axial direction (longitudinal direction). When taking the transverse or tangential direction, the mechanical properties shall be reduced by the percentage specified in Table 4. 5.2.3.2 For rings, discs and forgings with mainly rough deformation, the tensile and impact specimens shall be taken in the tangential direction. 5.2.4 Test method
5.2.4.1 The room temperature tensile test shall be in accordance with GB228. The high temperature tensile test shall be in accordance with GB4338. 5.2.4.2 The room temperature Aku impact test, room temperature Akv and low temperature Akv shall be in accordance with GB229. 5.2.4.3 The Brinell hardness test shall be in accordance with GB231. 257
258
Enlarged part
JB/T 5000. 8--1998
Extended part
A
Tangential test group
E
Longitudinal test specimen
Annealing or tempering
Extended part
Longitudinal test specimen
B
Extended part
Tempering and tempering
a) Shaft or square, rectangular forgings
Extended part
b) Hollow forgings
Tangential test specimen
c) Disc forgings
Heightened part
Tangential test specimen
Enlarged part
d) Ring forgings
Figure 1
Tangential test specimen||tt ||、Level test specimen
Tangential test specimen
Longitudinal test specimen
High part
Cut test specimen
Cut test specimen
Sampling position of various forgings
Mechanical properties
(no.2)
Ak
5.2.4.4
5.2.4.5
Test specimen direction
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
—1998
JB/T 5000. 8-
Table 4 Tangential and transverse mechanical properties indexes Reduction amount Alkali
Electric furnace steel forging ratio
>5
5
5
5
25
25
20
20
25
25
5
5
40
40
40
40
o
Property
1~25t steel chain forging
Forging ratio
2~3
5
10
5|| tt||10
25
25
25
30
30
35
>3～5
5
10
5
10
30
35
30
35
30
40
5
5
10
5
1.0
35
40
40
45
30
40
The grain size of steel is rated according to GB6394. Inclusions are rated according to GB10561. Macrostructure and defects of steel are tested and rated according to G3226 and GB1979. Flat
!
Furnace
Steel
≥25t Ingot Forging
Forging
Ratio
2~3
5
10
10
35
40
40
15
30
40
5.2.4.6
Ultrasonic flaw detection and magnetic particle flaw detection methods are recommended to comply with GB/T6402 and ASTMA275. 6 Acceptance, re-inspection and re-heat treatment
>3～5
5
10
5
10
40
50
40
50
40
50
%
>s
5
10
5
10
45
50
4.5
60
50
60
6.1 Forgings shall not have visible cracks, folds or other appearance defects that may affect their use. Local defects can be removed, and the false cleaning depth shall not exceed 75% of the machining allowance. Defects on the non-machined surface of the forging should be cleaned and smoothly transitioned, and the cleaning depth shall not exceed the forging size deviation of the manufacturer. Defects that exceed the machining allowance and forging size deviation can only be removed and repaired with the consent of the purchaser. 6.2 Forgings are not allowed to have white spots, internal cracks and residual shrinkage holes. 6.3 During the mechanical property test, if the test specimen has defects, as long as the mechanical properties do not meet the requirements due to cracks and white spots, re-sampling and testing are allowed as the initial test results. 6.4 When the initial test results of a certain mechanical property do not meet the requirements, it is allowed to take double samples at the adjacent position close to the unqualified sample for re-testing of the item, and the re-test results should all meet the requirements. If any result is still unqualified after the re-test, the forging can be re-heat treated and re-sampled. The number of re-heat treatments shall not exceed 2 times, and the number of tempering is unlimited. 7Quality certificate
The content of the quality certificate includes: forging name, steel grade, weight, quantity; contract number, drawing number, smelting number, forging number; various inspection results specified in the contract and drawings.
8Printing and packaging
8.1 The supplier prints the contract number, smelting number, and forging number on the forging equivalent to the ingot water outlet end. 8.2 The surface of the machined forging must be protected from rust. The forgings are packaged to avoid damage during transportation, 259
4 Test methods
5.2.4.1 Normal temperature tensile test shall comply with GB228. High temperature tensile test shall comply with GB4338. 5.2.4.2 Normal temperature Aku impact test, normal temperature Akv and low temperature Akv shall comply with GB229. 5.2.4.3 Brinell hardness test shall comply with GB231. 257
258
Enlarged part
JB/T 5000. 8--1998
Extended part
A
Tangential test group
E
Longitudinal test specimen
Annealing or tempering
Extended part
Longitudinal test specimen
B
Extended part
Tempering and tempering
a) Shaft or square, rectangular forgings
Extended part
b) Hollow forgings
Tangential test specimen
c) Disc forgings
Heightened part
Tangential test specimen
Enlarged part
d) Ring forgings
Figure 1Www.bzxZ.net
Tangential test specimen||tt ||、Level test specimen
Tangential test specimen
Longitudinal test specimen
High part
Interval test specimen
Cut dog test specimen
Sampling position of various forgings
Mechanical properties
(no.2)
Ak
5.2.4.4
5.2.4.5
Test specimen direction
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
—1998
JB/T 5000. 8-
Table 4 Tangential and transverse mechanical properties indexes Reduction amount Alkali
Electric furnace steel forging ratio
>5
5
5
5
25
25
20
20
25
25
5
5
40
40
40
40
o
Property
1~25t steel chain forgings
Forging ratio
2~3
5
10
5|| tt||10
25
25
25
30
30
35
>3～5
5
10
5
10
30
35
30
35
30
40
5
5
10
5
1.0
35
40
40
45
30
40
The grain size of steel is rated according to GB6394. Inclusions are rated according to GB10561. Macrostructure and defects of steel are tested and rated according to G3226 and GB1979. Flat
!
Furnace
Steel
≥25t Ingot Forging
Forging
Ratio
2~3
5
10
10
35
40
40
15
30
40
5.2.4.6
Ultrasonic flaw detection and magnetic particle flaw detection methods are recommended to comply with GB/T6402 and ASTMA275. 6 Acceptance, re-inspection and re-heat treatment
>3～5
5
10
5
10
40
50
40
50
40
50
%
>s
5
10
5
10
45
50
4.5
60
50
60
6.1 Forgings shall not have visible cracks, folds or other appearance defects that may affect their use. Local defects can be removed, and the false cleaning depth shall not exceed 75% of the machining allowance. Defects on the non-machined surface of the forging should be cleaned and smoothly transitioned, and the cleaning depth shall not exceed the forging size deviation of the manufacturer. Defects that exceed the machining allowance and forging size deviation can only be removed and repaired with the consent of the purchaser. 6.2 Forgings are not allowed to have white spots, internal cracks and residual shrinkage holes. 6.3 During the mechanical property test, if the test specimen has defects, as long as the mechanical properties do not meet the requirements due to cracks and white spots, re-sampling and testing are allowed as the initial test results. 6.4 When the initial test results of a certain mechanical property do not meet the requirements, it is allowed to take double samples at the adjacent position close to the unqualified sample for re-testing of the item, and the re-test results should all meet the requirements. If any result is still unqualified after the re-test, the forging can be re-heat treated and re-sampled. The number of re-heat treatments shall not exceed 2 times, and the number of tempering is unlimited. 7Quality certificate
The content of the quality certificate includes: forging name, steel grade, weight, quantity; contract number, drawing number, smelting number, forging number; various inspection results specified in the contract and drawings.
8Printing and packaging
8.1 The supplier prints the contract number, smelting number, and forging number on the forging equivalent to the ingot water outlet end. 8.2 The surface of the machined forging must be protected from rust. The forgings are packaged to avoid damage during transportation, 259
4 Test methods
5.2.4.1 Normal temperature tensile test shall comply with GB228. High temperature tensile test shall comply with GB4338. 5.2.4.2 Normal temperature Aku impact test, normal temperature Akv and low temperature Akv shall comply with GB229. 5.2.4.3 Brinell hardness test shall comply with GB231. 257
258
Enlarged part
JB/T 5000. 8--1998
Extended part
A
Tangential test group
E
Longitudinal test specimen
Annealing or tempering
Extended part
Longitudinal test specimen
B
Extended part
Tempering and tempering
a) Shaft or square, rectangular forgings
Extended part
b) Hollow forgings
Tangential test specimen
c) Disc forgings
Heightened part
Tangential test specimen
Enlarged part
d) Ring forgings
Figure 1
Tangential test specimen||tt ||、Level test specimen
Tangential test specimen
Longitudinal test specimen
High part
Interval test specimen
Cut dog test specimen
Sampling position of various forgings
Mechanical properties
(no.2)
Ak
5.2.4.4
5.2.4.5
Test specimen direction
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
Tangential
Transverse
—1998
JB/T 5000. 8-
Table 4 Tangential and transverse mechanical properties indexes Reduction amount Alkali
Electric furnace steel forging ratio
>5
5
5
5
25
25
20
20
25
25
5
5
40
40
40
40
o
Property
1~25t steel chain forgings
Forging ratio
2~3
5
10
5|| tt||10
25
25
25
30
30
35
>3～5
5
10
5
10
30
35
30
35
30
40
5
5
10
5
1.0
35
40
40
45
30
40
The grain size of steel is rated according to GB6394. Inclusions are rated according to GB10561. Macrostructure and defects of steel are tested and rated according to G3226 and GB1979. Flat
!
Furnace
Steel
≥25t ingot forging
Forging
Ratio
2~3
5
10
10
35
40
40
15
30
40
5.2.4.6
Ultrasonic flaw detection and magnetic particle flaw detection methods are recommended to comply with GB/T6402 and ASTMA275. 6 Acceptance, re-inspection and re-heat treatment
>3～5
5
10
5
10
40
50
40
50
40
50
%
>s
5
10
5
10
45
50
4.5
60
50
60
6.1 Forgings shall not have visible cracks, folds or other appearance defects that may affect their use. Local defects can be removed, and the false cleaning depth shall not exceed 75% of the machining allowance. Defects on the non-machined surface of the forging should be cleaned and smoothly transitioned, and the cleaning depth shall not exceed the forging size deviation of the manufacturer. Defects that exceed the machining allowance and forging size deviation can only be removed and repaired with the consent of the purchaser. 6.2 Forgings are not allowed to have white spots, internal cracks and residual shrinkage holes. 6.3 During the mechanical property test, if the test specimen has defects, as long as the mechanical properties do not meet the requirements due to cracks and white spots, re-sampling and testing are allowed as the initial test results. 6.4 When the initial test results of a certain mechanical property do not meet the requirements, it is allowed to take double samples at the adjacent position close to the unqualified sample for re-testing of the item, and the re-test results should all meet the requirements. If any result is still unqualified after the re-test, the forging can be re-heat treated and re-sampled. The number of re-heat treatments shall not exceed 2 times, and the number of tempering is unlimited. 7Quality certificate
The content of the quality certificate includes: forging name, steel grade, weight, quantity; contract number, drawing number, smelting number, forging number; various inspection results specified in the contract and drawings.
8Printing and packaging
8.1 The supplier prints the contract number, smelting number, and forging number on the forging equivalent to the ingot water outlet end. 8.2 The surface of the machined forging must be protected from rust. The forgings are packaged to avoid damage during transportation, 259
8-
Table 4 Reduction in tangential and transverse mechanical properties alkali
Forging ratio of electric furnace steel
>5
5
5||tt ||5
5
25
25
20
20
25
25
5
5
40
40
40
40
40
o
sex| |tt||1～25t steel chain forging forging
forging ratio
2~3
5
10
5
10
25
25
25
30
30
35
>3～5
5
10
5
10
30
35
30
35
30| |tt||40
5
5
10
5
1.0
35
40||tt ||40
45
30
40
The grain size of steel is rated according to GB6394. Inclusions are rated according to GB10561. The low-magnification structure and defects of steel are tested and rated according to G3226 and GB1979. Ping
!
furnace
steel
≥25t steel ingot forging forging
forging
forging
ratio
2~3|| tt||5
10
10
35
40
40
15
30||tt| |40
5.2.4.6
Ultrasonic flaw detection and magnetic particle flaw detection methods are recommended to be in accordance with GB/T6402 and ASTMA275. 6 Acceptance, re-inspection and re-heat treatment
>3～5
5
10
5
10
40||tt ||50
40
50
40
50
%
>s
5||tt| |10
5
10
45
50
4.5
60
50
60
6.1 Forgings are not allowed to have visible cracks, folds and other appearance defects that affect use. Local defects can be removed, and the depth of false cleaning shall not exceed 75% of the machining allowance. Defects on the non-machined surface of the forging should be cleaned up and smoothly transitioned, and the cleaning depth shall not exceed the dimensional deviation of the forgings produced by the manufacturer. Defects that exceed the machining allowance and dimensional deviation of forgings can be removed and repaired with the consent of the purchaser. 6.2 White spots, internal cracks and residual shrinkage cavities are not allowed to exist in forgings. 6.3 During the mechanical property test, if the test sample is defective, as long as the mechanical properties do not meet the requirements due to cracks and white spots, re-sampling for testing is allowed. As a result of the first test. 6.4 When the preliminary test results of a certain mechanical property do not meet the requirements, it is allowed to take double samples from the adjacent position close to the unqualified sample for retesting of the item. The retest results should all meet the requirements. If any of the results are still unsatisfactory after the retest, the forgings can be reheated and resampled for testing. The number of reheat treatments shall not exceed 2 times, and the number of temperings is not limited. 7 Quality Certificate
The content of the quality certificate includes: forging name, steel number, weight, quantity; contract number, drawing number, smelting number, forging number; inspection results specified in the contract and drawings.
8 Printing and packaging
8.1 The supplier prints the contract number, smelting number, and forging number on the nozzle end of the forging, which is equivalent to the steel ingot. 8.2 The surface of machined forgings must be protected against rust. Forgings are packaged to avoid damage during transportation, 259
8-
Table 4 Reduction in tangential and transverse mechanical properties alkali
Forging ratio of electric furnace steel
>5
5
5||tt ||5
5
25
25
20
20
25
25
5
5
40
40
40
40
40
o
sex| |tt||1～25t steel chain forging forging
forging ratio
2~3
5
10
5
10
25
25
25
30
30
35
>3～5
5
10
5
10
30
35
30
35
30| |tt||40
5
5
10
5
1.0
35
40||tt ||40
45
30
40
The grain size of steel is rated according to GB6394. Inclusions are rated according to GB10561. The low-magnification structure and defects of steel are tested and rated according to G3226 and GB1979. Ping
!
furnace
steel
≥25t steel ingot forging forging
forging
forging
ratio
2~3|| tt||5
10
10
35
40
40
15
30||tt| |40
5.2.4.6
Ultrasonic flaw detection and magnetic particle flaw detection methods are recommended to be in accordance with GB/T6402 and ASTMA275. 6 Acceptance, re-inspection and re-heat treatment
>3～5
5
10
5
10
40||tt ||50
40
50
40
50
%
>s
5||tt| |10
5
10
45
50
4.5
60
50
60
6.1 Forgings are not allowed to have visible cracks, folds and other appearance defects that affect use. Local defects can be removed, and the depth of false cleaning shall not exceed 75% of the machining allowance. Defects on the non-machined surface of the forging should be cleaned up and smoothly transitioned. The cleaning depth shall not exceed the dimensional deviation of the forgings produced by the manufacturer. Defects exceeding the machining allowance and dimensional deviation of forgings can be removed and repaired after obtaining the consent of the purchaser. 6.2 White spots, internal cracks and residual shrinkage cavities are not allowed in forgings. 6.3 During the mechanical property test, if the test sample is defective, as long as the mechanical properties do not meet the requirements due to cracks and white spots, re-sampling for testing is allowed. As a result of the first test. 6.4 When the preliminary test results of a certain mechanical property do not meet the requirements, it is allowed to take double samples from the adjacent position close to the unqualified sample for retesting of the item. The retest results should all meet the requirements. If any of the results are still unsatisfactory after the retest, the forgings can be reheated and resampled for testing. The number of reheat treatments shall not exceed 2 times, and the number of temperings is not limited. 7 Quality Certificate
The content of the quality certificate includes: forging name, steel number, weight, quantity; contract number, drawing number, smelting number, forging number; inspection results specified in the contract and drawings.
8 Printing and packaging
8.1 The supplier prints the contract number, smelting number, and forging number on the nozzle end of the forging, which is equivalent to the steel ingot. 8.2 The surface of machined forgings must be protected against rust. Forgings are packaged to avoid damage during transportation, 259
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