JB/T 6908-1993 Technical requirements for positive displacement compressor forgings
Some standard content:
Mechanical Industry Standard of the People's Republic of China
JB/T6908-1993
Positive Displacement Compressor Forgings
Technical Conditions
Published on 1993-07-13
Ministry of Machinery Industry of the People's Republic of China
Implemented on 1994-07-01
Mechanical Industry Standard of the People's Republic of China
Positive Displacement Compressor Forgings
Technical Conditions
Subject Content and Scope of Application
JB/T6908-1993
This standard specifies the technical requirements, test methods, inspection rules and marking requirements for steel forgings (hereinafter referred to as forgings) for positive displacement compressor mainframes.
This standard applies to free forgings (including die forgings) and die forgings for positive displacement compressors made of high-quality carbon steel, alloy structural steel and stainless steel produced on forging equipment such as forging hammers and hydraulic presses. 2
Quotation standards
GB 699
GB1220
GB1814
GB1979
GB3077
GB8539
GB10561
GB12362
GB/T 12 363
JB4249
JB4250
JB5440
JB5442
ZB J32 003.1~J32 003.8
JB/ZQ4000.7
Approved by the Ministry of Machinery Industry on July 13, 1993
Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished productsChemical analysis methods for steel and alloys
Method for acid etching test of macrostructure and defects of steelMetal tensile test method
Metal Charpy (U-notch) impact test methodMethod for testing Rockwell hardness of metal
Metal Brinell hardness test method
Technical conditions for high-quality carbon structural steel
Stainless steel bars
Method for fracture inspection of steel materials
Rating chart of macrostructure defects of structural steel
Technical conditions for alloy structural steel
Method for determination of average grain size of metal
General provisions for quality inspection of gear materials and heat treatment Microscopic evaluation method for non-metallic inclusions Tolerances and machining allowances of steel die forgings Functional classification of forgings
Steel free forgings on hammer
Machining allowances and tolerances
Machining allowances and tolerances of steel die forgings on hammer Ultrasonic flaw detection of forged steel parts of compressors
Magnetic particle flaw detection of important parts of compressors
Machining allowances and tolerances of free forgings on hydraulic presses General technical requirements for forgings
Method for examination of metal microstructure
Evaluation method for steel microstructure (free cementite, banded structure and Widmanstatten structure) 1994-07-01 Implementation
Technical requirements
JB/T6908-1993
Forgings shall be manufactured in accordance with the provisions of this standard, according to the drawings and technical documents approved through the prescribed procedures or according to the contract. 3.1 Steel for forgings
Forgings can be made directly from killed steel ingots, or from rolled products or forged products for pressure processing. 3.1.1
3.1.2 Steel for forgings should be accompanied by a quality certificate from the quality inspection department of the steel production unit. In the absence of a quality certificate or in doubt, the forging unit should re-inspect the steel, and only after passing the inspection can forging be carried out. 3.1.3 All surface defects of steel for forgings must be removed, and materials with cracks, folds, etc. that affect the forging quality are not allowed to be forged. The riser and tail of the forging ingot must be cut off, and the two ends after cutting should ensure that there are no shrinkage holes, cracks, inclusions, etc. that affect the performance. 3.1.4
3.2 Forging Manufacturing
3.2.1 Forgings shall be thermomechanically formed by hydraulic presses, forging hammers, die forging hammers or die forging presses, etc. These forging machines shall have sufficient energy to fully deform the entire cross section of the steel and forge to a shape and size as close to the finished product as possible. 3.2.2 The heating of the rough, the initial and final forging temperatures, forging, and cooling after forging in the manufacture of forgings shall be carried out in accordance with the process specifications of the forging unit. 3.3 Heat Treatment of Forgings
The heat treatment state of forgings shall comply with the technical documents or contract provisions. The heat treatment specifications shall be specified by the forging unit. When the bending and warping deformations produced by the heat treatment of forgings exceed the tolerance range, they shall be straightened by the forging unit. All forgings that have been cold-corrected or hot-corrected shall be tempered to eliminate internal stress. 3.4 Chemical composition
The chemical composition of forgings shall meet the following standard requirements: a. High-quality carbon structural steel forgings shall comply with the provisions of GB699; b. Alloy structural steel forgings shall comply with the provisions of GB3077; c. Stainless steel forgings shall comply with the provisions of GB1220. 3.5 Mechanical properties
3.5.1 The mechanical property test of forgings can be carried out on longitudinal, tangential or radial specimens. The results of the longitudinal specimen test shall comply with the provisions of Table 1 or the contract. The performance requirements of special steel grades shall be specified in the drawings or order contracts. When the mechanical property test of forgings is measured by tangential or radial specimens, the percentage of reduction in its mechanical property index shall comply with the provisions of Table 2.
Mechanical properties
Heat treatment
Sectional size
>100~300
>300~500
>500~700
≤100
>100~300
>300~500
>500~750
>750~1000| |tt||103~156
149187
143~187
137~187
20MnMo
36CrMo
40CrNiMo
30CrMoAl
42CrMo
Heat treatment
Section size
≤100
>100~300
≤100
>100-300
>300~500
>500~750
≤200
≤100
>100-300
>300~500||t t||>500~800
>100 ~ 300 | | tt | | > 300 ~ 500 | | tt | | > 100 ~ 300 | | tt | 00-250
JB/T 6908-1993
Continued Table 1
156~207
170~217
162-217
156~217
217~255
241~286
229~269
217~25 5
207~269
≤229
241~286
≥159
≥192
JB/T 6908—1993
Percentage of mechanical property reduction
Radial test specimen
Cross-section size ≤300mm
Cross-section size>300mm
According to the classification provisions of GB/T12363,
according to design requirements, working characteristics and uses, forgings are divided into I,
II, IIII and IV categories. Forging
category should be indicated in product drawings, technical documents and forging drawings. Those not indicated shall be treated as IV category forgings. The necessary inspection items for each category of forgings shall be in accordance with the provisions of Table 3, and gear forgings shall be in accordance with the provisions of GB8539. Table 3
Forging 1
Inspection items
Mechanical property test
o or.
HBS or HR
Metallographic test
$、Agtu
Ultrasonic or magnetic particle inspection
(according to the drawing or contract)
Low power test
Mechanical property test
o or.
Metallographic test
E、Agu
Ultrasonic or magnetic particle inspection
(according to the drawing or contract)
Hardness HBS or HR
Low power test
Hardness HBS or HR
Inspection quantity
or percentage
1 piece per ingot
2% of each batch, 1
but not less than
2 pieces. Die forgings: 1 piece per batch
1 piece per ingot
5% per batch, but not less than 5 pieces
Conditions for forming a batch
Same furnace steel
Same heat treatment
Treatment times 2》
Same steel grade
Same heat treatment
Treatment times 2)
Parts examples
Piston force ≥ 80kN: crankshaft, high-pressure cylinder block, high-pressure cylinder head with valve hole, etc.
Connecting rod, piston rod, connecting rod bolt, Piston rod nut, high-pressure cylinder head, crosshead pin, crosshead connector and crankshaft with piston force <80kN, high-pressure cylinder block, high-pressure cylinder head with valve hole, etc., transmission shaft, rotor, half coupling and internal gear sleeve and external gear sleeve of gear coupling of rotary compressor, etc., valve seat, valve cover, bearing seat, etc., lift limiter, etc., Note: 1) The I, I, IIII and IV forgings of this standard are respectively equivalent to the V, IV, IIII and II forgings of JB/ZQ4000.7. 2) In the same heat treatment furnace, the same type of forgings treated once or continuously with the same process specification are the same heat treatment heat. 3.6 Geometric shape and appearance quality of forgings, the shape and size of forgings shall comply with the provisions of forging drawings and process documents. The machining allowance and tolerance on the forging drawing shall meet the following standard requirements: free forgings on hydraulic press shall comply with the provisions of ZBJ32003.1~J32003.8; steel free forgings on hammer shall comply with the provisions of JB4249; steel die forgings on hammer shall comply with the provisions of JB4250; steel die forgings shall comply with the provisions of GB12362.
Overburned forgings must be scrapped.
JB/T 6908-1993
3.6.4 If there are defects such as cracks, shrinkage holes, folds, interlayers, forging scratches, etc. on the surface of forgings, they shall be handled in accordance with the following provisions: a. For the non-machined surface of forgings, local defects within the range of forging size deviation are allowed to be removed, and the surface of forgings shall have a smooth transition after repairing the defects:
b When the depth of the surface defect of the forging exceeds the machining allowance, if the purchaser agrees, the defect can be completely removed and then repaired by welding according to the specified process regulations.
3.6.5 The cleaning of forging surface shall be specified in the drawing or order contract. 3.7 Internal quality of forgings
3.7.1 Forgings shall not have white spots or cracks. Forgings with white spots must be scrapped. 3.7.2 Crankshafts, connecting rods, piston rods, high-pressure cylinder blocks, high-pressure cylinder heads with valve holes, high-pressure cylinder heads, crosshead pins, rotors, transmission shafts, inner gear sleeves and outer gear sleeves of half couplings or gear couplings, etc. shall be subject to metallographic inspection, and steel ingot forgings shall also be subject to macroscopic inspection. Except for white spots and cracks, macroscopic and metallographic inspections are not used as acceptance basis. If required, they shall comply with the following provisions: 3.7.2.1 Macroscopic structure
a. Macroscopic defects shall be evaluated in accordance with the provisions of GB1979. General looseness, central looseness and general point segregation shall not be less than level 3;
b. For steel ingot forgings, test pieces shall be taken from each ingot, and the test pieces shall be taken from the riser end. Forgings forged from rolled materials with material qualification certificates are exempt from low-magnification structure inspection.
3.7.2.2 Metallographic structure
a. The Widmanstatten structure shall not be less than Grade 1 according to the provisions of YB31; b. The grain size shall be evaluated according to GB6394: forgings with a diameter or thickness not exceeding 300mm shall not be less than Grade 5, and forgings with a diameter or thickness exceeding 300mm shall not be less than Grade 4;
C. Non-metallic inclusions shall be evaluated according to GB10561: A, B, C, and D type inclusions shall not be less than Grade 3 each, the sum of A and C inclusions shall not be less than Grade 3, and the sum of B and D inclusions shall not be less than Grade 3: d. For metallographic tests, samples shall be taken from the end of the tensile or impact specimen. 3.8 Nondestructive testing
After machining, compressor Class I and Class I forgings shall be subjected to ultrasonic testing or magnetic particle testing according to the drawings or contract requirements. The ultrasonic testing method and defect level shall be in accordance with the provisions of JB5440, and the qualified level shall be in accordance with the provisions of Appendix A (Supplement) of this standard; the magnetic particle testing method and defect level shall be in accordance with the provisions of JB5442, and the qualified level shall be in accordance with the provisions of Appendix B (Supplement) of this standard. 4 Test methods and inspection rules
4.1 Test specimens for chemical analysis of forgings shall be in accordance with the provisions of GB222. The chemical analysis of forgings shall be carried out in accordance with the provisions of GB223 or other methods that can ensure the necessary accuracy of the measurement.
4.2 The mechanical property test of forgings shall be carried out in accordance with the provisions of GB228 and GB229, and the hardness test shall be carried out in accordance with the provisions of GB230 and GB231. 4.3 Metallographic tests of forgings shall be carried out in accordance with the provisions of YB28, YB31, GB6394 and GB10561. 4.4 White spots shall be inspected by low power or ultrasonic flaw detection, and determined by fracture inspection when necessary. The test and inspection methods shall be in accordance with the provisions of GB226, GB1979, GB1814 and JB5440.
4.5 Ultrasonic flaw detection inspection method shall be in accordance with the provisions of JB5440, and magnetic particle flaw detection inspection method shall be in accordance with the provisions of JB5442. 4.6 The locations of the specimens selected for the mechanical property test of forgings shall be indicated in the forging drawings in accordance with the following provisions. Special sampling shall be determined by negotiation between the user and the forging unit and indicated in the forging drawings. 4.6.1 Longitudinal specimens of the rotor, crankshaft, connecting rod and piston rod shall be taken from one end. The rotor and crankshaft shall be taken at the end connected to the driver, and the piston rod shall be taken at the end connected to the ten-head.
4.6.2 Samples of high-pressure cylinder bodies, high-pressure cylinder heads with valve holes, high-pressure cylinder heads, etc., are taken at the riser end of the steel ingot. If several high-pressure cylinder heads, high-pressure cylinder heads, etc. are forged from the same steel ingot, samples are taken at both ends of the multiple ingots. 5
JB/T6908-1993
The cutting position of the sample for the mechanical property test of forgings is: 4.6.3
a. Solid shaft forgings (round, square or rectangular); take at least d/6 from the surface or 1/6 of the thickness: b. Hollow shaft forgings: Take the specimen at 1/2 of the wall thickness, and take twice the thickness as the section for calculating mechanical properties: Ring and disc forgings: The tangential specimens are taken from 1/2 of the wall thickness or height, and the smaller of the wall thickness and height is taken as the section for calculating mechanical properties:
d. The positions of specimens for different types of forgings are shown in Figure 1. a Shaft forgings
b Hollow forgings
c Disc forgings
d Ring forgings
4.7 Number of mechanical property specimens: In each group of tests, there shall be no less than 1 tensile specimen and no less than 2 impact specimens. 4.8 The batch inspection method for forgings shall be in accordance with the provisions of Table 3. 4.9 In addition to the appearance quality inspection of all forgings, the supplier's quality inspection department shall also conduct tests according to the test items specified in the forging category to which it belongs and the test items specified in the contract, and issue a quality certificate. 4.10
The acceptance of finished forgings shall be carried out by the quality inspection department of the purchaser according to the quality certificate and relevant documents of the forging unit. 4.11
1 Repeated test
JB/T6908-1993
a. When the mechanical properties are unqualified, double the number of specimens must be taken for a second test of the unqualified items. After the second test, even if one specimen is unqualified, the forging is judged to be unqualified, and the forging is allowed to be reheat treated. After reheat treatment, cut a group of specimens (1 pulling and 2 punching) for testing, but the total heat treatment shall not exceed three times. The number of tempering is not counted. b. When the specimen or test result is invalid, take the original number of specimens for retesting. Marking, certificate, packaging and transportation
The prominent parts of the forgings that have passed the inspection shall be clearly and firmly marked. 5.1
The marking content shall at least include:
Steel grade:
b.Furnace number:
Trademark (logo of the forging unit).
Forgings shall be accompanied by a certificate of conformity provided by the forging unit. The content shall at least include:
Name or code of the forging unit:
Drawing number, forging name, order contract number: Steel grade, furnace number:
Chemical composition of forgings and various test results specified by forging categories; Quantity and weight of forgings:
Delivery heat treatment status:
Appearance quality and main geometric dimensions of forgings: h. Seal of the quality inspection department and signature of the inspection personnel. Packaging and transportation
The packaging and transportation of forgings shall be in accordance with the provisions of the technical agreement or production contract7
JB/T6908-1993
Appendix A
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors (supplement)
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors, see Figures A1 to A8 and Table A1. A1
Qubo area
Qulao area-Southern + 24
This silver area
A area = thread + d
JB/T 6908-1993
Ganchang Mobao
Parts name
d±220mm
d>$/220 mm
S100mm
S>100 mm
Piston rod
Parts name
d±220mm
d> ±220 mm
Crosshead connector
High pressure cylinder head and cover
Fanjia Jiyanguan
Cylinder head short side thickness
≤200 mm
Thickness of short side of cylinder head
>200 mm
ds±250mm
d> 250 mm
Coupling
Detection area
From the near surface of the workpiece in the turning area
The meeting area
From the near surface of the workpiece outside the turning area
The meeting area
The near surface of the workpiece in the turning area
The meeting area
The near surface of the workpiece outside the turning area
The meeting area
Stress-bearing part of the connecting rod body
《Big and small heads）
Other areas
Stress-bearing part of the connecting rod body
(Big and small heads)
Other areas
Area A and workpiece crown surface
Other Remaining (near center R)
Detection area
Near surface of workpiece
Rest area
Reverse surface of workpiece
Rest area
Near surface of workpiece
Near surface of workpiece
Flange and neck
Flange and neck
Near surface of workpiece
(Solid quantity d, hollow number B)
Rest area
Near surface of workpiece
(Solid number d, hollow number)
Rest area
Near surface of workpiece (number 8)
Note: The “near surface” not specified is.
Equal slowness of single defect
Equivalent diameter of defect
Continued Table A1
Equal slowness of single defect
Equivalent diameter of defect
≤ 04
Grade of wave reduction caused by defect
Wave reduction caused by defect
>14-20
Grade of defect concentration area
Defect concentration area accounts for
Percentage of total damage area
Grade of wave reduction caused by defect
Grade of defect concentration area
Wave reduction caused by defect
>14~20
Defect concentration area accounts for
Percentage of total damage area
Figure A2
Figure A4
Figure A7
#, b, e
JB/T 6908-1993
JB/T690819937 Number of mechanical property test specimens: each group of tests shall include at least 1 tensile test specimen and at least 2 impact test specimens. 4.8 The batch inspection method for forgings shall be in accordance with the provisions of Table 3. 4.9 In addition to the appearance quality inspection of all forgings, the supplier's quality inspection department shall also conduct tests according to the test items specified in the forging category to which it belongs and the test items specified in the contract, and issue a quality certificate. 4.10
The acceptance of finished forgings shall be carried out by the buyer's quality inspection department according to the quality certificate and relevant documents of the forging unit. 4.11
1 Repeated test
JB/T6908-1993
a. When the mechanical properties are unqualified, double the number of specimens must be taken for a second test of the unqualified items. After the second test, even if one specimen is unqualified, the forging is judged to be unqualified, and the forging is allowed to be re-heat treated. After re-heat treatment, cut a group of specimens (1 tension and 2 impact) for testing, but the total heat treatment shall not exceed three times. The number of tempering is not counted. b. When the sample or test result is invalid, take the original number of samples for retesting. Marking, Certificate, Packaging and Transportation
The notable parts of the qualified forgings shall be clearly and firmly marked. 5.1
The marking content shall at least include:
Steel grade:
b.Furnace number:
Trademark (logo of the forging unit).
Forgings shall be accompanied by a certificate of conformity provided by the forging unit. The content shall at least include:
Name or code of the forging unit:
Drawing number, forging name, order contract number: Steel grade, furnace number:
Chemical composition of forgings and various test results specified by forging category; Quantity and weight of forgings:
Delivery heat treatment status:
Appearance quality and main geometric dimensions of forgings: h. Seal of the quality inspection department and signature of the inspector. Packaging and transportation
The packaging and transportation of forgings shall be in accordance with the provisions of the technical agreement or production contract7
JB/T6908-1993
Appendix A
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors (supplement)
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors, see Figures A1 to A8 and Table A1. A1
Qubo area
Qulao area-Southern + 24
This silver area
A area = thread + d
JB/T 6908-1993
Ganchang Mobao
Parts name
d±220mm
d>$/220 mm
S100mm
S>100 mm
Piston rod
Parts name
d±220mm
d> ±220 mm
Crosshead connector
High pressure cylinder head and cover
Fanjia Jiyanguan
Cylinder head short side thickness
≤200 mm
Thickness of short side of cylinder head
>200 mm
ds±250mm
d> 250 mm
Coupling
Detection area
From the near surface of the workpiece in the turning area
The meeting area
From the near surface of the workpiece outside the turning area
The meeting area
The near surface of the workpiece in the turning area
The meeting area
The near surface of the workpiece outside the turning area
The meeting area
Stress-bearing part of the connecting rod body
《Big and small heads）
Other areas
Stress-bearing part of the connecting rod body
(Big and small heads)
Other areas
Area A and workpiece crown surface
Other Remaining (near center R)
Detection area
Workpiece near surface
Rest area
Workpiece reverse surface
Rest area
Workpiece near surface and
Workpiece near surface
Flange and neck
Flange and neck
Workpiece near surface
(solid quantity d, hollow number B)
Rest area
Workpiece near surface
(solid number d, hollow number)
Rest area
Workpiece near surface (number 8)
Note: The “near surface” not specified is.
Equal slowness of single defect
Equivalent diameter of defect
Continued Table A1
Equal slowness of single defect
Equivalent diameter of defect
≤ 04
Grade of wave reduction caused by defect
Wave reduction caused by defect
>14-20
Grade of defect concentration area
Defect concentration area accounts for
Percentage of total damage area
Grade of wave reduction caused by defect
Grade of defect concentration area
Wave reduction caused by defect
>14~20
Defect concentration area accounts for
Percentage of total damage area
Figure A2
Figure A4
Figure A7
#, b, e
JB/T 6908-1993
JB/T690819937 Number of mechanical property test specimens: each group of tests shall include at least 1 tensile test specimen and at least 2 impact test specimens. 4.8 The batch inspection method for forgings shall be in accordance with the provisions of Table 3. 4.9 In addition to the appearance quality inspection of all forgings, the supplier's quality inspection department shall also conduct tests according to the test items specified in the forging category to which it belongs and the test items specified in the contract, and issue a quality certificate. 4.10
The acceptance of finished forgings shall be carried out by the buyer's quality inspection department according to the quality certificate and relevant documents of the forging unit. 4.11
1 Repeated test
JB/T6908-1993
a. When the mechanical properties are unqualified, double the number of specimens must be taken for a second test of the unqualified items. After the second test, even if one specimen is unqualified, the forging is judged to be unqualified, and the forging is allowed to be re-heat treated. After re-heat treatment, cut a group of specimens (1 tension and 2 impact) for testing, but the total heat treatment shall not exceed three times. The number of tempering is not counted. b. When the sample or test result is invalid, take the original number of samples for retesting. Marking, Certificate, Packaging and Transportation
The significant parts of the qualified forgings shall be clearly and firmly marked. 5.1
The marking content shall at least include:
Steel grade:
b.Furnace number:
Trademark (logo of the forging unit).
Forgings shall be accompanied by the certificate of conformity provided by the forging unit. The content shall at least include:
Name or code of the forging unit:
Drawing number, forging name, order contract number: Steel grade, furnace number:
Chemical composition of forgings and various test results specified by forging categories; Quantity and weight of forgings:
Delivery heat treatment status:
Appearance quality and main geometric dimensions of forgings: h. Seal of the quality inspection department and signature of the inspector. Packaging and transportation
The packaging and transportation of forgings shall be in accordance with the provisions of the technical agreement or production contract7
JB/T6908-1993
Appendix A
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors (supplement)
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors, see Figures A1 to A8 and Table A1. A1
Qubo area
Qulao area-Southern + 24
This silver area
A area = thread + d
JB/T 6908-1993
Ganchang Mobao
Parts name
d±220mm
d>$/220 mm
S100mm
S>100 mm
Piston rod
Parts name
d±220mm
d> ±220 mm
Crosshead connector
High pressure cylinder head and cover
Fanjia Jiyanguan
Cylinder head short side thickness
≤200 mm
Thickness of short side of cylinder head
>200 mm
ds±250mm
d> 250 mm
Coupling
Detection area
From the near surface of the workpiece in the turning area
The meeting area
From the near surface of the workpiece outside the turning area
The meeting area
The near surface of the workpiece in the turning area
The meeting area
The near surface of the workpiece outside the turning area
The meeting area
Stress-bearing part of the connecting rod body
《Big and small heads）
Other areas
Stress-bearing part of the connecting rod body
(Big and small heads)
Other areas
Area A and workpiece crown surface
Other Remaining (near center R)
Detection area
Near surface of workpiece
Rest area
Reverse surface of workpiece
Rest area
Near surface of workpiece
Near surface of workpiece
Flange and neck
Flange and neck
Near surface of workpiece
(Solid quantity d, hollow number B)
Rest area
Near surface of workpiece
(Solid number d, hollow number)
Rest area
Near surface of workpiece (number 8)
Note: The “near surface” not specified is.
Equal slowness of single defect
Equivalent diameter of defect
Continued Table A1
Equal slowness of single defect
Equivalent diameter of defect
≤ 04
Grade of wave reduction caused by defect
Wave reduction caused by defect
>14-20
Grade of defect concentration area
Defect concentration area accounts for
Percentage of total damage area
Grade of wave reduction caused by defect
Grade of defect concentration area
Wave reduction caused by defect
>14~20
Defect concentration area accounts for
Percentage of total damage area
Figure A2
Figure A4
Figure A7
#, b, e
JB/T 6908-1993
JB/T69081993Furnace number:
Trademark (logo of the forging unit).
Forgings should be accompanied by a certificate of conformity provided by the forging unit. The content should at least include:
Name or code of the forging unit:
Drawing number, forging name, order contract number: Steel grade, furnace number:
Chemical composition of forgings and various test results specified by forging categories; Quantity and weight of forgings:
Delivery heat treatment status:
Appearance quality and main geometric dimensions of forgings: h. Seal of the quality inspection department and signature of the inspection personnel. Packaging and transportation
The packaging and transportation of forgings shall be in accordance with the provisions of the technical agreement or production contract7
JB/T6908-1993
Appendix A
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors (supplement)
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors, see Figures A1 to A8 and Table A1. A1
Qubo area
Qulao area-Southern + 24
This silver area
A area = thread + d
JB/T 6908-1993
Ganchang Mobao
Parts name
d±220mm
d>$/220 mm
S100mm
S>100 mm
Piston rod
Parts name
d±220mm
d> ±220 mm
Crosshead connector
High pressure cylinder head and cover
Fanjia Jiyanguan
Cylinder head short side thickness
≤200 mm
Thickness of short side of cylinder head
>200 mm
ds±250mm
d> 250 mm
Coupling
Detection area
From the near surface of the workpiece in the turning area
The meeting area
From the near surface of the workpiece outside the turning area
The meeting area
The near surface of the workpiece in the turning area
The meeting area
The near surface of the workpiece outside the turning area
The meeting area
Stress-bearing part of the connecting rod body
《Big and small heads）
Other areas
Stress-bearing part of the connecting rod body
(Big and small heads)
Other areas
Area A and workpiece crown surface
Other Remaining (near center R)
Detection area
Near surface of workpiece
Rest area
Reverse surface of workpiece
Rest area
Near surface of workpiece
Near surface of workpiece
Flange and neck
Flange and neck
Near surface of workpiece
(Solid quantity d, hollow number B)
Rest area
Near surface of workpiece
(Solid number d, hollow number)
Rest area
Near surface of workpiece (number 8)
Note: The “near surface” not specified is.
Equal slowness of single defect
Equivalent diameter of defect
Continued Table A1
Equal slowness of single defect
Equivalent diameter of defect
≤ 04
Grade of wave reduction caused by defect
Wave reduction caused by defect
>14-20
Grade of defect concentration area
Defect concentration area accounts for
Percentage of total damage area
Grade of wave reduction caused by defect
Grade of defect concentration area
Wave reduction caused by defect
>14~20
Defect concentration area accounts for
Percentage of total damage area
Figure A2
Figure A4
Figure A7
#, b, e
JB/T 6908-1993
JB/T69081993Furnace number:
Trademark (logo of the forging unit).
Forgings should be accompanied by a certificate of conformity provided by the forging unit. The content should at least include:
Name or code of the forging unit:
Drawing number, forging name, order contract number: Steel grade, furnace number:
Chemical composition of forgings and various test results specified by forging categories; Quantity and weight of forgings:
Delivery heat treatment status:
Appearance quality and main geometric dimensions of forgings: h. Seal of the quality inspection department and signature of the inspection personnel. Packaging and transportationwww.bzxz.net
The packaging and transportation of forgings shall be in accordance with the provisions of the technical agreement or production contract7
JB/T6908-1993
Appendix A
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors (supplement)
Defect assessment of ultrasonic flaw detection for Class I and Class II forgings of positive displacement compressors, see Figures A1 to A8 and Table A1. A1
Qubo area
Qulao area-Southern + 24
This silver area
A area = thread + d
JB/T 6908-1993
Ganchang Mobao
Parts name
d±220mm
d>$/220 mm
S100mm
S>100 mm
Piston rod
Parts name
d±220mm
d> ±220 mm
Crosshead connector
High pressure cylinder head and cover
Fanjia Jiyanguan
Cylinder head short side thickness
≤200 mm
Thickness of short side of cylinder head
>200 mm
ds±250mm
d> 250 mm
Coupling
Detection area
From the near surface of the workpiece in the turning area
The meeting area
From the near surface of the workpiece outside the turning area
The meeting area
The near surface of the workpiece in the turning area
The meeting area
The near surface of the workpiece outside the turning area
The meeting area
Stress-bearing part of the connecting rod body
《Big and small heads）
Other areas
Stress-bearing part of the connecting rod body
(Big and small heads)
Other areas
Area A and workpiece crown surface
Other Remaining (near center R)
Detection area
Near surface of workpiece
Rest area
Reverse surface of workpiece
Rest area
Near surface of workpiece
Near surface of workpiece
Flange and neck
Flange and neck
Near surface of workpiece
(Solid quantity d, hollow number B)
Rest area
Near surface of workpiece
(Solid number d, hollow number)
Rest area
Near surface of workpiece (number 8)
Note: The “near surface” not specified is.
Equal slowness of single defect
Equivalent diameter of defect
Continued Table A1
Equal slowness of single defect
Equivalent diameter of defect
≤ 04
Grade of wave reduction caused by defect
Wave reduction caused by defect
>14-20
Grade of defect concentration area
Defect concentration area accounts for
Percentage of total damage area
Grade of wave reduction caused by defect
Grade of defect concentration area
Wave reduction caused by defect
>14~20
Defect concentration area accounts for
Percentage of total damage area
Figure A2
Figure A4
Figure A7
#, b, e
JB/T 6908-1993
JB/T69081993
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