HG/T 2741-1995 Technical requirements for carbon steel castings for pressure vessels
Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T2741—95
Technical Conditions for Carbon Steel Castings for Pressure Vessels
Published on 1995—10—18
Ministry of Chemical Industry of the People's Republic of China
Implementation on 199601—01
Chemical Industry Standard of the People's Republic of China
Technical Conditions for Carbon Steel Castings for Pressure Vessels
Subject Content and Scope of Application
HG/T2741—95
This standard specifies the technical requirements for the manufacture, inspection and acceptance of carbon steel castings for pressure vessels. This standard applies to carbon steel castings of pressure-bearing parts such as valves, flanges, pipe fittings, etc. assembled with other cast steels, forged steels or steel plates by fusion welding. Cited standards
Steel chemical analysis sample sampling method and finished product chemical composition allowable deviation GB222
Methods for chemical analysis of steel and alloys
Metal exhibition tensile test method
Metal bending test method
GB2106
GB5677
Metal ratio (V-notch) impact test method Cast steel grade indication method
Radiographic and film grade classification method of steel castings Surface roughness comparison sample casting surface
Casting size tolerance
GB7233
GB9443|| tt||GB9444
Methods for ultrasonic flaw detection and quality rating of steel castings Penetrant flaw detection and defect display trace rating of steel castings Magnetic particle flaw detection and quality rating of steel castings GB/T11350 Machining allowance of castings
GB11352
Casting carbon steel parts for general engineering
3 Grades
This standard includes two steel grades, ZG205-415R and ZG275-485R: The grade indication method is in accordance with the provisions of GB5613. The "R" at the end of the grade is the first capital letter of the Chinese pinyin of the word "容", indicating container steel. 4 Technical requirements
4.1 Refining
Unless otherwise specified, the steelmaking method should adopt electric furnace or open-hearth smelting. 4.2 Chemical composition
The chemical composition of each grade should comply with the provisions of Table 1. The Ministry of Chemical Industry of the People's Republic of China approved the residual element plan on October 18, 1995 and implemented on January 1, 1998. The total content of residual element is 2741-95. Chemical composition: ZG205-415R ZG275-485R a25② Note: ① For every 0.01% lower carbon content than the prescribed upper limit, manganese can exceed the prescribed upper limit by 0.04%, and the manganese content is allowed to be as high as 1.10%. ② For every 0.01% lower carbon content than the prescribed upper limit, manganese can exceed the prescribed upper limit by 0.04%, and the maximum manganese content is allowed to be 1.40%. ③ When additional requirements for carbon equivalent (CE) are specified, the maximum value of the total amount of the remaining yuan shall not be used. 4.3 Mechanical properties
The room temperature mechanical properties of each grade shall comply with the provisions of Table 2 Table 2 Room temperature mechanical properties
ZG205-4152
ZG275-485R
. Heat treatment
Yield strength or on
≥ 275
. 1 Castings shall be delivered in the heat treatment state of normalizing and tempering Tensile strength.
415~585
485~655
4.4.2 Normalizing, heating above Ac3 and air cooling. Tempering: heating below Ac1, 4.4.3 After the casting is sintered and cooled to below the phase change temperature, heat treatment can be carried out. The heat treatment furnace temperature should be effectively controlled.
4.5 Surface quality
4.5.1 The surface roughness of the casting shall comply with the provisions of the sample or order agreement. If there is no provision in the sample or order agreement, the surface roughness of the casting shall comply with the provisions of GB6060.1. .5.2 The surface of the casting shall be free of defects such as sand adhesion, pores, shrinkage, cracks and meatiness. 4.6 Geometric shape and size
The geometric shape and size of the casting shall comply with the provisions of the drawing or order agreement. 4.? Dimension tolerance, machining allowance
Sectional reduction
HG/T2741—95
The dimensional tolerance and machining allowance of the casting shall comply with the provisions of the drawing or order agreement. If there is no provision in the sample or order agreement, the machining allowance of the casting shall comply with the provisions of GB/T11350, and the dimensional tolerance of the casting shall comply with the provisions of CT14 grade in GB8414. 4.8 Defect Repair
The supplier may repair defects in castings by welding, but welding should not affect mechanical properties. It is not allowed to prevent leakage by hammering, caulking or dipping.
4.9 Welding Repair
4.9.1 Welding repair operations should be performed by welders with skilled welding skills. 4.9.2 Before welding repair, the defective parts of the castings should be cleaned. When castings are produced according to A4 or A5 in Appendix A (Supplement), the welded parts should be inspected by magnetic particle or penetrant testing before and after welding according to the same standards as the castings. 4.9.3 When castings are produced according to A6 or A7 in Appendix A, if any of the following three situations occur, ultrasonic or radiographic inspection should be carried out according to the same standards as the castings after welding repair and grinding: a. Castings found to be leaking after water pressure test
b. c. Castings where the depth of the area to be welded exceeds 20% of the wall thickness or 25mm (whichever is smaller); c. Castings where the area of the area to be welded is greater than 65cm. 4.9.4 When a casting has any of the three defects a, b, and c in 4.9.3, stress relief heat treatment should be carried out after welding. 4.10 Hydrostatic Test
4, 10.1 Each casting shall be subjected to a hydrostatic test according to the test pressure and holding time specified in the drawing or order agreement. The final test result shall be that the casting shall not leak.
4.10.2 The hydrostatic test of the casting can be carried out before delivery by the manufacturer or after mechanical processing by the purchaser. In either case, the manufacturer shall be responsible for the performance of the casting that meets the requirements of 4.10.1. 4.11 Additional Item Requirements
When the purchaser has additional item requirements, they can be selected according to Appendix A and the number and name of the additional item shall be specified in the order agreement. 5 Test methods
5.1 Chemical analysis
5.1.1 Test blocks for chemical analysis shall be prepared during the pouring process. 5.1.2 The sampling method for chemical analysis shall be carried out in accordance with GB222. 5.1.3 The chemical analysis method shall be carried out in accordance with GB223. 5.2 Tensile test
5.2.1. Test blocks for tensile test shall be cast separately during the pouring process. The type of test block shall be the double-bezoar test block specified in GB11352. 5.2.2 The shape, size and cutting position of the single-cast test block and the tensile test sample shall comply with the provisions of GB11352. 5.2.3 The single test block and the casting it represents shall be heat treated in the same heat treatment furnace at the same time. 5.2.4 The tensile test shall be carried out in accordance with GB228. 5.3 Test methods for additional items
5.3.1 The Charpy impact test shall be carried out in accordance with GB2106. 5.3.2 The bending test shall be carried out in accordance with the provisions of GB232. 5.3.3 The magnetic particle inspection shall be carried out in accordance with the provisions of GB9444. 5.3.4 The penetrant inspection shall be carried out in accordance with the provisions of GB9443. 5.3.5 The radiographic inspection shall be carried out in accordance with the provisions of GB5677, and 5.3.6 The ultrasonic inspection shall be carried out in accordance with the provisions of GB7233. .3.
6 Inspection rules
HG/T2741—95
6.1 Inspection authority and location
6.1.1 The inspection of castings is generally carried out by the inspection department of the supplier. According to the provisions of the order agreement, the buyer may also participate or conduct separate inspections. 6.1.2 Except for the chemical analysis of the finished product, all other inspection items shall be carried out at the supplier's manufacturing site. 6.1.3 When the buyer conducts the inspection, the supplier shall provide reasonable and convenient conditions for the buyer's inspector, and the buyer's inspection work shall not affect the supplier's normal production. And the supplier's safety regulations should be followed. If the supplier does not send an inspector to the site for inspection at the agreed time, the supplier can conduct the inspection on its own and submit the inspection results to the screening party.
6.1.4 When the supplier and the supplier have a dispute over the inspection results, it can be arbitrated by a third-party authoritative inspection agency. 6.2 Division of inspection batches
6.2.1 The inspection batch of chemical composition is the castings cast from each smelting furnace as one inspection batch. 6.2.2 The inspection batch of mechanical properties is the castings cast from each smelting furnace and heat treated in the same heat treatment furnace as one inspection batch.
6.3 Chemical composition inspection
8.3.1 A chemical composition analysis is carried out once for each smelting furnace, and the analysis results should comply with the provisions of Table 1. Chip specimens should be obtained from 6mm below the casting surface,
6.3.2 When conducting chemical analysis of finished products with squares, samples should be taken from test blocks or castings representing each smelting heat for analysis. Chip samples should be taken from 6mm below the casting surface. The analysis results are qualified if they do not exceed the allowable deviation of finished product analysis in Table 3. Unqualified ones can be used as the basis for rejection. The allowable deviation of finished product analysis in Table 3 cannot be used as the acceptance standard for analysis during smelting in the manufacturer. Table 3 Permissible deviation of finished product analysis
Residual elements:
Deviation limit calculation formula②
0.03×%CL+0.02
0.08×%MnL+0.01
0.22×%SIL-0.01
0.13%×%PL+0.005
0.36×%SL+0.001
0.10×%N+0.03
0.07×%CrL+0.04
0.04X%MoL+0.03
0.23×%V1+0.004
ZG205-415R
Allowable deviation value (%)
Refers to the element limit applicable to the formula calculation
Note, ① Range
② The footnote L of the chemical element in the formula means substituting the upper limit of the element in the cast steel grade into the formula to calculate the tolerance 6.4 Mechanical properties test
6.4.1 Take a tensile test specimen from each batch, and the test results shall comply with the requirements of Table 2. 8.4.2 The test results that do not meet the requirements due to the following reasons are invalid. In this case, the test should be re-conducted according to Article 6.4.1. 4.
ZG275-485R
Allowable deviation value (%)
HG/T2741--95
8: Improper installation of the specimen or malfunction of the testing machine; b. The tensile specimen is broken outside the gauge length;
Improper specimen processing;
d. Casting defects exist in the specimen
6.4.3 In addition to the provisions of Article 6.4.2, when the mechanical property test results of the casting do not meet the requirements, it is allowed to take two spare tensile specimens from the same batch for re-testing. If the re-test results of the two specimens meet the requirements of Table 2, the tensile properties of the batch of castings are still qualified. If the re-test results of one specimen still do not meet the requirements during the re-test, it can be handled according to Article 6.4.4. 6.4.4 When the mechanical properties retest results still do not meet the requirements of Table 2, the castings and test blocks may be reheat treated and then retested according to 6.4.1. The number of reheat treatments shall not exceed two times (except tempering)6.5 Rounding of test results
The mechanical properties and chemical composition test results may be rounded according to the principles of the test methods specified in the standard. The dimensional measurement results cannot be rounded.
8.6 The inspection of surface quality, geometric shape, dimensional tolerance, machining margin and water pressure test shall be inspected piece by piece according to 4.5, 4.6, 4.7 and 4.10. 6.7 Inspection of additional items
Inspect the additional item requirements specified in the acceptance order agreement. Marking, packaging, transportation, storage and quality certificate 7
7.1 Marking
The casting shall have the cast steel grade (such as ZG275-485R) and the melting furnace number and the manufacturer's code. Packaging, transportation and storage
After the casting passes the inspection, it shall be protected or packaged. The surface anticorrosion, transportation and storage of the casting shall comply with the order agreement. 7.3 Quality certificate
The supplier shall provide the purchaser with a casting quality certificate. The quality certificate shall include the following contents: implementation standard number;
cast steel grade:
melting furnace number:
heat treatment furnace number:
chemical composition analysis report:
mechanical properties test report;
casting water pressure test report,
casting size inspection report;
additional project inspection report specified in the order agreement: manufacturer name:
name of the organization issuing the quality certificate.
casting quality certificates are generally issued by the inspection department of the manufacturer, and can also be issued by a third-party inspection organization. The data must be accurate, the handwriting must be clear and neat, and the organization must be responsible for issuing the documents.
HG/T2741-95
Additional items
(Supplement)
The following additional items are available for the purchaser to choose, but the required item number and name must be specified in the order agreement agreed upon by both parties. Al Carbon equivalent
A1.1 When the party has requirements for carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalent
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than the value specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with the provisions of GB7233.
Additional instructions:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 1996005
0.36×%SL+0.001
0.10×%N+0.03
0.07×%CrL+0.04
0.04X%MoL+0.03
0.23×%V1+0.004
ZG205-415R
Allowable deviation value (%)
Refers to the element limit applicable to the formula calculation
Note, ① Range
② The footnote L of the chemical element in the formula means that the upper limit of the element in the cast steel grade is substituted into the formula to calculate the tolerance. 6.4 Mechanical properties test
6.4.1 Take a tensile test specimen from each batch. The test results shall conform to the requirements of Table 2. 8.4.2 The test results that do not meet the requirements due to the following reasons are invalid. In this case, the test should be re-conducted according to Article 6.4.1. 4.
ZG275-485R
Allowable deviation value (%)
HG/T2741--95
8: Improper installation of the specimen or malfunction of the testing machine; b. The tensile specimen is broken outside the gauge length;
Improper specimen processing;
d. Casting defects exist in the specimen
6.4.3 In addition to the provisions of Article 6.4.2, when the mechanical property test results of the casting do not meet the requirements, it is allowed to take two spare tensile specimens from the same batch for re-testing. If the re-test results of the two specimens meet the requirements of Table 2, the tensile properties of the batch of castings are still qualified. If the re-test results of one specimen still do not meet the requirements during the re-test, it can be handled according to Article 6.4.4. 6.4.4 When the mechanical properties retest results still do not meet the requirements of Table 2, the castings and test blocks may be reheat treated and then retested according to 6.4.1. The number of reheat treatments shall not exceed two times (except tempering)6.5 Rounding of test results
The mechanical properties and chemical composition test results may be rounded according to the principles of the test methods specified in the standard. The dimensional measurement results cannot be rounded.
8.6 The inspection of surface quality, geometric shape, dimensional tolerance, machining margin and water pressure test shall be inspected piece by piece according to 4.5, 4.6, 4.7 and 4.10. 6.7 Inspection of additional items
Inspect the additional item requirements specified in the acceptance order agreement. Marking, packaging, transportation, storage and quality certificate 7
7.1 Marking
The casting shall have the cast steel grade (such as ZG275-485R) and the melting furnace number and the manufacturer's code. Packaging, transportation and storage
After the casting passes the inspection, it shall be protected or packaged. The surface anticorrosion, transportation and storage of the casting shall comply with the order agreement. 7.3 Quality certificate
The supplier shall provide the purchaser with a casting quality certificate. The quality certificate shall include the following contents: implementation standard number;
cast steel grade:
melting furnace number:
heat treatment furnace number:
chemical composition analysis report:
mechanical properties test report;
casting water pressure test report,
casting size inspection report;
additional project inspection report specified in the order agreement: manufacturer name:
name of the organization issuing the quality certificate.
casting quality certificates are generally issued by the inspection department of the manufacturer, and can also be issued by a third-party inspection organization. The data must be accurate, the handwriting must be clear and neat, and the organization must be responsible for issuing the documents.
HG/T2741-95
Additional items
(Supplement)
The following additional items are available for the purchaser to choose, but the required item number and name must be specified in the order agreement agreed upon by both parties. Al Carbon equivalent
A1.1 When the party has requirements for carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalent
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than that specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with the provisions of GB7233.
Additional instructions:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 1996005
0.36×%SL+0.001
0.10×%N+0.03
0.07×%CrL+0.04
0.04X%MoL+0.03
0.23×%V1+0.004
ZG205-415R
Allowable deviation value (%)
Refers to the element limit applicable to the formula calculation
Note, ① Range
② The footnote L of the chemical element in the formula means that the upper limit of the element in the cast steel grade is substituted into the formula to calculate the tolerance. 6.4 Mechanical properties test
6.4.1 Take a tensile test specimen from each batch and the test results shall conform to the requirements of Table 2. 8.4.2 The test results that do not meet the requirements due to the following reasons are invalid. In this case, the test should be re-conducted according to Article 6.4.1. 4.
ZG275-485R
Allowable deviation value (%)
HG/T2741--95
8: Improper installation of the specimen or malfunction of the testing machine; b. The tensile specimen is broken outside the gauge length;
Improper specimen processing;
d. Casting defects exist in the specimen
6.4.3 In addition to the provisions of Article 6.4.2, when the mechanical property test results of the casting do not meet the requirements, it is allowed to take two spare tensile specimens from the same batch for re-testing. If the re-test results of the two specimens meet the requirements of Table 2, the tensile properties of the batch of castings are still qualified. If the re-test results of one specimen still do not meet the requirements during the re-test, it can be handled according to Article 6.4.4. 6.4.4 When the mechanical properties retest results still do not meet the requirements of Table 2, the castings and test blocks may be reheat treated and then retested according to 6.4.1. The number of reheat treatments shall not exceed two times (except tempering)6.5 Rounding of test results
The mechanical properties and chemical composition test results may be rounded according to the principles of the test methods specified in the standard. The dimensional measurement results cannot be rounded.
8.6 The inspection of surface quality, geometric shape, dimensional tolerance, machining margin and water pressure test shall be inspected piece by piece according to 4.5, 4.6, 4.7 and 4.10. 6.7 Inspection of additional items
Inspect the additional item requirements specified in the acceptance order agreement. Marking, packaging, transportation, storage and quality certificate 7
7.1 Marking
The casting shall have the cast steel grade (such as ZG275-485R) and the melting furnace number and the manufacturer's code. Packaging, transportation and storage
After the casting passes the inspection, it shall be protected or packaged. The surface anticorrosion, transportation and storage of the casting shall comply with the order agreement. 7.3 Quality certificate
The supplier shall provide the purchaser with a casting quality certificate. The quality certificate shall include the following contents: implementation standard number;
cast steel grade:
melting furnace number:
heat treatment furnace number:
chemical composition analysis report:
mechanical properties test report;
casting water pressure test report,
casting size inspection report;
additional project inspection report specified in the order agreement: manufacturer name:
name of the organization issuing the quality certificate.
casting quality certificates are generally issued by the inspection department of the manufacturer, and can also be issued by a third-party inspection organization. The data must be accurate, the handwriting must be clear and neat, and the organization must be responsible for issuing the documents.
HG/T2741-95
Additional items
(Supplement)
The following additional items are available for the purchaser to choose, but the required item number and name must be specified in the order agreement agreed upon by both parties. Al Carbon equivalent
A1.1 When the party has requirements for carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalentbzxZ.net
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than the value specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with the provisions of GB7233.
Additional instructions:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 19962, when the mechanical properties test results of the castings do not meet the requirements, it is allowed to take two spare tensile specimens from the same batch for re-testing. If the re-test results of the two specimens meet the requirements of Table 2, the tensile properties of the batch of castings are still qualified. If the re-test results of one specimen still do not meet the requirements during the re-test, it can be handled in accordance with Article 6.4.4. 6.4.4 When the mechanical properties re-test results still do not meet the requirements of Table 2, the castings and test blocks can be re-heat treated and then re-tested in accordance with Article 6.4.1. The number of re-heat treatments shall not exceed two times (except tempering) 6.5 Rounding of test results
Mechanical properties and chemical composition test results can be rounded according to the principles of the test methods specified in the standard. Dimension measurement results cannot be rounded.
8.6 The inspection of surface quality, geometric shape, dimensional tolerance, machining margin and water pressure test shall be inspected piece by piece in accordance with Articles 4.5, 4.6, 4.7 and 4.10. 6.7 Inspection of additional items
Inspect and accept the additional items specified in the order agreement. Marking, packaging, transportation, storage and quality certificate 7
7.1 Marking
The casting should have the cast steel grade (such as ZG275-485R) and the melting furnace number and the manufacturer's code Packaging, transportation and storage
After the casting passes the inspection, it should be protected or packaged. The surface anti-corrosion, transportation and storage of the casting should comply with the order agreement. 7.3 Quality certificate
The supplier shall provide the purchaser with a casting quality certificate. The quality certificate shall include the following contents: implementation standard number;
cast steel grade:
melting furnace number:
heat treatment furnace number:
chemical composition analysis report:
mechanical properties test report;
casting water pressure test report,
casting size inspection report;
additional project inspection report specified in the order agreement: manufacturer name:
name of the organization issuing the quality certificate.
casting quality certificates are generally issued by the inspection department of the manufacturer, and can also be issued by a third-party inspection organization. The data must be accurate, the handwriting must be clear and neat, and the organization must be responsible for issuing the documents.
HG/T2741-95
Additional items
(Supplement)
The following additional items are available for the purchaser to choose, but the required item number and name must be specified in the order agreement agreed upon by both parties. Al Carbon equivalent
A1.1 When the party has requirements for carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalent
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than the value specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with the provisions of GB7233.
Additional instructions:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 1996Except for the provisions of Article 2, when the mechanical property test results of the casting do not meet the requirements, it is allowed to take two spare tensile test specimens from the same batch for re-testing. If the re-test results of the two test specimens meet the requirements of Table 2, the tensile properties of the batch of castings are still qualified. If the re-test results of one test specimen still do not meet the requirements during the re-test, it can be handled in accordance with Article 6.4.4. 6.4.4 When the mechanical property re-test results still do not meet the requirements of Table 2, the castings and test blocks can be re-heat treated and then re-tested in accordance with Article 6.4.1. The number of re-heat treatments shall not exceed two times (except tempering) 6.5 Rounding of test results
Mechanical property and chemical composition test results can be rounded according to the principles of the test methods specified in the standard. Dimension measurement results cannot be rounded.
8.6 The inspection of surface quality, geometric shape, dimensional tolerance, machining margin and water pressure test shall be inspected piece by piece in accordance with Articles 4.5, 4.6, 4.7 and 4.10. 6.7 Inspection of additional items
Inspect and accept the additional items specified in the order agreement. Marking, packaging, transportation, storage and quality certificate 7
7.1 Marking
The casting should have the cast steel grade (such as ZG275-485R) and the melting furnace number and the manufacturer's code Packaging, transportation and storage
After the casting passes the inspection, it should be protected or packaged. The surface anti-corrosion, transportation and storage of the casting should comply with the order agreement. 7.3 Quality certificate
The supplier shall provide the purchaser with a casting quality certificate. The quality certificate shall include the following contents: implementation standard number;
cast steel grade:
melting furnace number:
heat treatment furnace number:
chemical composition analysis report:
mechanical properties test report;
casting water pressure test report,
casting size inspection report;
additional project inspection report specified in the order agreement: manufacturer name:
name of the organization issuing the quality certificate.
casting quality certificates are generally issued by the inspection department of the manufacturer, and can also be issued by a third-party inspection organization. The data must be accurate, the handwriting must be clear and neat, and the organization must be responsible for issuing the documents.
HG/T2741-95
Additional items
(Supplement)
The following additional items are available for the purchaser to choose, but the required item number and name must be specified in the order agreement agreed upon by both parties. Al Carbon equivalent
A1.1 When the party has requirements for carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalent
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than that specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with the provisions of GB7233.
Additional instructions:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 19961 When the strip has requirements on carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalent
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than that specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with the provisions of GB7233.
Additional instructions:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 19961 When the strip has requirements on carbon equivalent, the carbon equivalent of the two grades of cast steel shall comply with the provisions of Table A1. Table A1 Carbon equivalent
ZG205-415R
ZG275-485R
A1.2 Carbon equivalent is calculated according to the following formula:
Cr+Mo+vNi+Cu
(%)
Wherein: C, Mn, Cr, Mo, Ni, V, Cu are the percentages of each element respectively. A2 Charpy impact test
(A1)
A2.1 The Charpy (V-notch) impact test method shall be carried out in accordance with GB2106. The impact specimen shall be cut from a single cast keel test block. A2.2 Take three Charpy (V-notch) impact specimens from each smelting furnace for impact test. The test average value (arithmetic mean) of the three specimens shall not be less than the value specified in Table A2. Only one of the three specimens is allowed to have a test value less than the minimum average value, but shall not be less than two-thirds of the minimum average value.
Table A2 Impact properties of cast steel
ZB205-415R
ZG275-485R
(Minimum average value)
A2.3 If the test values of two of the three samples are lower than the minimum average value specified in Table A2, or the test value of one sample is lower than two-thirds of the minimum average value specified in Table A2, three spare samples should be taken for retesting, and the test value of each retested sample should be equal to or exceed the minimum average value specified in Table A2. A3 Bending test
A3.1 A bending test is carried out once for each melting furnace. The bending sample is cut from a single cast kiel test block and processed into a 25mmX13mm section with a fillet radius of no more than 1.6mm. A3.2 The bending test operation is carried out in accordance with GB232. A3.3. The sample subjected to longitudinal bending at room temperature is bent at a 90° angle around a compression ring with a diameter equal to the thickness of the sample section. The outer surface of the bent part of the sample should be free of cracks.
A3.4 If the sample shows poor processing or cracks, it can be scrapped. And it can be replaced by another sample from the same smelting furnace and the same heat treatment furnace.
A4 Magnetic particle flaw detection
When magnetic particle flaw detection is used to detect surface and near-surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9444.
A5 Diagnostic flaw detection
HG/T 2741-95
When diagnostic flaw detection is used to detect surface defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer. The acceptance standard shall be implemented in accordance with GB9443.
A6 Radiographic inspection
When the X-ray method is used to inspect the internal defects of castings, the inspection scope and quality level shall be agreed upon by the supplier and the buyer, and the acceptance standard shall be implemented in accordance with GB5677. Radiographic inspection shall be carried out after the final heat treatment of the castings. A7 Ultrasonic flaw detection
When ultrasonic flaw detection is used to detect internal defects of castings, the inspection scope and quality level shall be agreed upon by the supply and demand parties, and the acceptance criteria shall be implemented in accordance with GB7233.
Additional remarks:
This standard is proposed by China National Chemical Equipment Corporation. This standard is under the jurisdiction of the Chemical Machinery Research Institute of the Ministry of Chemical Industry. This standard was drafted by Jinxi Chemical Machinery Factory and the Chemical Machinery Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Gao Xiyuan, Guai Jiansheng, Xu Ziping, An Weiping, Sun Guayu, and Zhang Sujie. People's Republic of China
Chemical Industry Standard
Technical Conditions for Carbon Steel Castings for Pressure Vessels
HG/T2741-95
Editor China National Chemical Equipment Corporation
Postal Code 100011
Printer Beijing University of Chemical Technology
Copyright reserved
Format 880×1230
First Edition June 1996
No Reprinting
13.5 thousand words
First Printing June 1996
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