Some standard content:
GB18248—2000
This standard adopts the Japanese JIS G3429—1988 Seamless Steel Tube for High-Pressure Containers, and is formulated in combination with the supply and demand of non-chain steel tubes for gas cylinders in my country.
Compared with JIS G3429—1988, this standard adds the low-power inspection and non-metallic inclusion inspection of steel tubes made directly from steel ingots and the non-metallic inclusion inspection of steel tubes made from continuous casting tubes; the heat treatment specification of steel tube samples and the mechanical properties and non-destructive testing after heat treatment are changed from negotiation items to mandatory items. This standard is proposed by the State Metallurgical Industry Bureau. This standard is under the jurisdiction of the National Steel Standardization Technical Committee. The drafting units of this standard: Shanghai Baosteel Group Corporation, Metallurgical Industry Information Standards Research Institute, Tianjin Steel Pipe Company. Drafters of this standard: Qian Qiugen, Li Yuguang, Wu Yuequan, Feng Wenhua, Zhang Baoli 1 Scope
National Standard of the People's Republic of China
Seamless steel tubes for gas cylinder
Seamless steel tubes for gas cylinder GB18248—2000
This standard specifies the dimensions, shape, weight, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of seamless steel tubes for gas cylinders
This standard applies to hot-rolled or cold-rolled (drawn) seamless steel tubes for manufacturing gas cylinders. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. When this standard is published, the versions shown are all valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest versions of the following standards: GB/T 222—1984 Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products GB/T 223.5--1997 Chemical analysis methods for steel and alloys - Reduced molybdenum silicate photometric method for determination of acid-soluble silicon content GB/T 223.11—1991 Chemical analysis methods for steel and alloys - Ammonium persulfate oxidation volumetric method for determination of chromium content GR/T 223.12—1991 GB/T 223.14—1989 GB/T 223.19—1989 GB/T 223.23—1994 GB/T 223.26—1989 GB/T 223.62—1988 GB/T 223. 63—1988
GB/T 223. 681997
GB/T 223. 69—1997
GB/T 226 1991
GB/T 228—1987
GB/T 229—1994
GB/T241—1990
Methods for chemical analysis of iron, steel and alloys. Sodium carbonate separation-diextraction carbonyl distillation spectrophotometric determination of chromium content. Chemical analysis methods of iron, steel and alloys. Molybdenum reagent extraction spectrophotometric determination of vanadium content. New cuproline-chloroform extraction spectrophotometric determination of copper content. Diacetyl spectrophotometric determination of nickel content.
Methods for chemical analysis of iron, steel and alloys.
Methods for chemical analysis of iron, steel and alloys.
Methods for chemical analysis of iron, steel and alloys.
Direct thiocyanate spectrophotometric determination of molybdenum content.
Methods for chemical analysis of iron, steel and alloys. Method
Determination of phosphorus content by butyl acetate extraction spectrophotometry
Chemical analysis methods for steel and alloys
Chemical analysis methods for steel and alloys
Determination of manganese content by sodium (potassium) periodate spectrophotometry
Determination of sulfur content by potassium iodate titration after combustion in a tubular furnaceChemical analysis methods for steel and alloys
Determination of carbon content by gas volumetric method after combustion in a tubular furnaceMacrostructure and defect acid etching test method for steelMetal tensile test method
Metal Charpy notched impact test method
Metal pipe hydraulic test method
GB/T 1979—1980
Grading chart of macrostructure defects in structural steel
GB/T2102—1988
GB/T 4336—1984
GB/T 5777—1996
GB/T 7735—1995
Acceptance, packaging, marking and quality certificate of steel tubesPhotoelectric emission spectrum analysis method for carbon steel and medium and low alloy steelsUltrasonic flaw detection test method for seamless steel tubes
Eddy current flaw detection test method for steel tubes
GB/T10561—1989Microscopic evaluation method for non-metallic inclusions in steelGB/T 12606—1999
GB/T 17395- 1998
GB/T 17505—1998
Method for magnetic leakage detection of steel pipe
Dimensions, shape, weight and allowable deviation of seamless steel pipesGeneral technical requirements for delivery of steel and steel products
Approved by the State Administration of Quality and Technical Supervision on October 25, 2000 and implemented on September 1, 2001
GB 18248--2000
YB/T 5137—1998
Seamless steel pipe for high pressure, round pipe, broken
3. Dimensions, shape, straightness
3.1 Outside diameter and wall thickness
3.1.1 The outside diameter and wall thickness of steel pipes shall comply with the provisions of Table 1 Table 1 Outside diameter and wall thickness of steel pipes
140(139.7)
According to the requirements of the purchaser and after consultation between the supply and demand parties, steel pipes with specifications other than those in Table 1 may be supplied. 3.1.2 The allowable deviations of the outer diameter and wall thickness of steel pipes shall comply with the requirements of Table 2. Wall
4. 0.4. 5, 5. 0, 5. 5, 6. 0
4. 5, 7. 5
4. 5, 5. 0.8. 0
5. 0, 5. 5
7. 0, 8. 0
6. 3, 6. 5.7. 0
6. 3, 7. 0
7. 5, 8. 2, 9. 0
Table 2 Permissible deviation of outer diameter and wall thickness of steel pipe Type of steel pipe
Hot rolled pipebzxZ.net
Cold rolled (drawn) steel pipe
3.2 Length
3.2.1 Normal length
The normal length of steel pipe is 4000~12000mm. 3.2.2 Fixed length and multiple length
Allowable deviation of outer diameter
Allowable deviation of outer diameter and wall thickness, %
Allowable deviation of total thickness
The fixed length of steel pipe shall be within the normal length range, and the allowable deviation of length is as follows: +°mm when length ≤600mm:
*mm when length ≥6000mm.
The total length of steel pipe in multiple lengths shall be within the normal length range. The allowable deviation of the total length is +mm. mm
GB 1824B—2000
Each multiple length shall leave a cutout margin according to the following provisions: 5~10mm when outer diameter ≤159mml
10~15 mm when outer diameter ≥159 mm.
3.3 Appearance
3.3.1 Curvature
The curvature of steel pipe shall not be greater than 1.5 mm/ml. 3. 3.2 Roundness and uneven wall thickness
According to the requirements of the purchaser, after negotiation between the supply and demand parties and indicated in the contract, the ovality and uneven wall thickness of the steel pipe shall not exceed 80% of the outer diameter and wall thickness tolerance respectively.
3.3.3 End shape
The end faces of the steel pipe at both ends shall be perpendicular to the axis of the steel pipe, and the burrs on the cut shall be removed. 3.4 Delivery weight
The steel pipe shall be delivered according to the actual weight or the theoretical weight. The theoretical weight of the steel pipe shall be calculated according to the provisions of GB/T 17395, and the density of steel shall be 7. 85 kg/dm*.
According to the requirements of the purchaser, after negotiation between the supply and demand parties and indicated in the contract, the deviation between the actual weight and the theoretical weight of the delivered steel pipe shall comply with the following provisions:
Single steel pipe: ±10%
Steel pipes with a minimum of 10t per batch: ±7.5%
3.5 Marking example
Steel pipes made of 35CrMo steel with an outer diameter of 108 mm and a wall thickness of 4 mm: a) Hot-rolled steel pipes with a length of 4000 mm are marked as: 35CrMo-108X4X4000-GB 18248-2000b) Cold rolled (drawn) steel pipe, length 8000mm, marked as: cold 35CrMo-108×4X8000-GB18248-20004 Technical requirements
4.1 Steel grade and chemical composition
4.1.1 Steel grade and chemical composition (melting analysis> shall comply with the provisions of Table 3. 4.1.2 When the purchaser requires finished product analysis,It should be indicated in the contract. The allowable deviation of the chemical composition of the finished steel pipe compared with Table 3 shall comply with the provisions of GB/T222. Table 3 Steel grades and chemical composition
34Mn2v
30CrMo
35CrMo
Chemical composition, %
0. 030≤0. 030≤0. 0550. 30
≤0.030≤0. 030≤0. 055
0.030#0.03040.055
0, 07 ~~
4.2 Manufacturing method
4.2.1 Manufacturing method of steel
Steel shall be smelted in electric furnace or oxygen converter. 4.2.2 Manufacturing method of steel pipe
GB18248--2000
Steel pipes shall be manufactured by hot rolling or cold rolling (drawing). 4.3 Delivery status
Hot-rolled steel pipes shall be delivered in hot-rolled state, and cold-rolled (drawn) steel pipes shall be delivered in normalized or annealed state. 4.4 Mechanical properties
The longitudinal mechanical properties of the test specimens made from heat-treated rough steel pipes shall comply with the requirements of Table 4. Table 4 Room temperature longitudinal mechanical properties
Heat treatment
Tensile strength
34Mn2V
30CrMo
35CrMo
Normalizing
Temperature, C
Coolant
Water, oil
Water, oil
Temperature, ℃
Quenching agent
Water, oil
Water, oil
The allowable adjustment range of the heat treatment temperature listed in the table: quenching, normalizing temperature ± 20°C; tempering temperature ≤ 50°C. Mechanical properties
Yield point
Elongation after fracture
Not less than
Shenjigong
2When standard specimens are not prepared, small-sized specimens such as 7.5mm, 5mm or 3mm in width can be used. The impact energy Aku.p measured by the small-size sample is converted into the impact energy Abu2 of the standard sample by the following formula: Alu2=8X10XAu.p/5p
Where: Sr——Cross-sectional area of the notch of the sample, mm, the impact energy measured by the small sample,.
3 Evaluation of the impact test results According to the provisions of GB/T17505, 4 The supplier shall conduct a 20°C or 50°C V-notch impact test on the steel pipe, provide reference and accumulate data 4.5 Solidity
The solidity test of the steel pipe can be carried out by hydraulic test or non-destructive testing, and the test method is selected by the supplier. 4.5.1 During the hydraulic test, the steel pipe shall not leak under the test pressure of 5MPa, and the test pressure shall be maintained for not less than 5s. 4.5.2 Non-destructive testing can be carried out by eddy current testing or magnetic flux leakage testing. Eddy current testing shall be carried out according to the acceptance level A of GB/T7735. The magnetic flux leakage flaw detection shall be in accordance with L4 of GB/T12606. 4.6 Low-power inspection and non-metallic inclusion inspection 4.6.1 The steel pipes made directly from steel ingots shall be inspected at low power. There shall be no visible white spots, inclusions, subcutaneous bubbles, skin folding and delamination on the aldehyde-impregnated test piece of the steel pipe cross section.
Steel pipes made directly from steel ingots and steel pipes made from continuous casting pipes shall be inspected for non-metallic inclusions. The non-metallic inclusions of steel pipes shall be rated according to the JK series rating chart in GB/T10561. A, B, C, D types of inclusions shall be judged according to the most serious one, and the level shall not be greater than 2.5 levels respectively.
4.6.2 The low-power inspection and non-metallic inclusion inspection of rolled (forged) pipes and the low-power inspection of continuous casting pipes shall be carried out on the pipes and shall comply with the provisions of YB/T5137.
4.7 Surface quality
GB1B248—2000
There shall be no cracks, folds, roll breaks, delamination and scarring on the inner and outer surfaces of the steel pipe. These defects must be completely removed, the removed area should be smooth, and the removal depth shall not exceed the negative deviation of the nominal wall thickness. The actual wall thickness at the cleaned area shall not be less than the minimum allowable wall thickness. Other local defects whose depth does not exceed the negative deviation of the wall thickness are allowed to exist. 4.8 Non-destructive testing
Copper pipes shall be subjected to ultrasonic flaw detection inspection one by one in accordance with the provisions of GB/T5777, cold-rolled (drawn) steel pipes shall be graded C5, and hot-rolled steel pipes shall be negotiated by the supply and demand parties.
Steel pipes that have been hydraulically inspected can be subjected to end magnetic flaw detection inspection one by one in accordance with L2 of GB/T12606. 5 Test methods
5.1 The size and shape of the steel pipe shall be measured one by one using measuring tools that meet the accuracy requirements. 5.2 The inner and outer surfaces of the steel pipe shall be visually inspected one by one under sufficient lighting conditions. Visual inspection, 5.3 Other inspections of steel pipes shall comply with the provisions of Table 5. Table 5 Inspection items, test methods and sampling quantity of steel pipes No.
Inspection items
Chemical composition
Tensile test
Impact test
Axillary pressure test
Eddy current flaw detection
Magnetic flux leakage flaw detection
Ultrasonic operation
Macro inspection
Non-metallic inclusion inspection
Inspection rules
6.1 Inspection and acceptance
Test method
GB/T 222,GB/T 223.GE/T 4336
GB/T 228
GB/T229
GB/T 241
GB/T7735
GB/T12606
GB/T 5777
GB/T 226.GB/T 1979
GB/T 10561
The inspection and acceptance of steel pipes shall be carried out by the supplier's technical supervision department. 6.2 Batch rules
Quantity of sampling
Take 1 sample for each expansion
Take 1 sample on each of the two steel pipes for each batch
Take 3 samples on each of the two steel pipes for each batch
Take 1 sample on each of the two steel pipes for each batch
Take 1 sample on each of the two steel pipes for each batch
Steel pipes shall be inspected and accepted in batches. Each batch of steel pipes shall be of the same grade, The steel pipes are composed of the same furnace () number, the same specification and the same delivery status, and the number of sections in each batch shall not exceed 200. 6.3 Sampling quantity
The sampling quantity of each batch of copper pipes for various tests shall comply with the provisions of Table 5. 6.4 Re-inspection and judgment rules
The re-inspection and judgment rules of steel pipes shall comply with the provisions of GB/T2102 and GB/T17505. 7 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel pipes shall comply with the provisions of GB/T2102.5 Solidity
The solidity test of steel pipe can be carried out by hydraulic test or non-destructive testing, and the test method is selected by the supplier. 4.5.1 During the hydraulic test, the steel pipe shall not show leakage under the test pressure of 5MPa, and the test pressure shall be maintained for not less than 5s. 4.5.2 Non-destructive testing can be carried out by eddy current testing or magnetic leakage testing. Eddy current testing shall be carried out according to the acceptance level A of GB/T7735. Magnetic leakage testing shall be carried out according to L4 of GB/T12606. 4.6 Low-power inspection and non-metallic inclusion inspection 4.6.1 Steel pipes made directly from steel ingots shall be subject to low-power inspection. There shall be no visible white spots, inclusions, subcutaneous bubbles, skin folding and delamination on the aldehyde-impregnated test piece of the cross section of the steel pipe.
Steel pipes made directly from steel ingots and steel pipes made from continuous casting pipes shall be subject to non-metallic inclusion inspection. The non-metallic inclusions of steel pipes shall be rated according to the JK series rating chart in GB/T10561. A, B, C, D types of inclusions shall be judged according to the most serious ones, and the level shall not be greater than 2.5 levels respectively.
4.6.2 The low-power inspection of rolled (forged) pipes and the low-power inspection of non-metallic inclusions and the low-power inspection of continuous casting pipes shall be carried out on the pipes and shall comply with the provisions of YB/T5137.
4.7 Surface quality
GB1B248—2000
The inner and outer surfaces of steel pipes shall not have cracks, folds, rolling folds, delamination and scarring. These defects must be completely removed, the removed area should be smooth, and the removal depth shall not exceed the negative deviation of the nominal wall thickness. The actual wall thickness at the cleaned area shall not be less than the minimum value allowed by the wall thickness. Other local defects whose depth does not exceed the negative deviation of the wall thickness are allowed to exist. 4.8 Non-destructive testing
Copper tubes shall be subjected to ultrasonic flaw detection according to the provisions of GB/T5777. Cold-rolled (drawn) steel tubes shall be subjected to C5 grade, and hot-rolled steel tubes shall be negotiated by the supply and demand parties.
Steel tubes that have been hydraulically tested can be subjected to end magnetic flaw detection according to L2 of GB/T12606. 5 Test methods
5.1 The size and shape of steel tubes shall be measured one by one using measuring tools that meet the accuracy requirements. 5.2 The inner and outer surfaces of the steel tubes shall be visually inspected one by one under sufficient lighting conditions. Visual inspection, 5.3 Other inspections of steel pipes shall comply with the provisions of Table 5. Table 5 Inspection items, test methods and sampling quantity of steel pipes No.
Inspection items
Chemical composition
Tensile test
Impact test
Axillary pressure test
Eddy current flaw detection
Magnetic flux leakage flaw detection
Ultrasonic operation
Macro inspection
Non-metallic inclusion inspection
Inspection rules
6.1 Inspection and acceptance
Test method
GB/T 222,GB/T 223.GE/T 4336
GB/T 228
GB/T229
GB/T 241
GB/T7735
GB/T12606
GB/T 5777
GB/T 226.GB/T 1979
GB/T 10561
The inspection and acceptance of steel pipes shall be carried out by the supplier's technical supervision department. 6.2 Batch rules
Quantity of sampling
Take 1 sample for each expansion
Take 1 sample on each of the two steel pipes for each batch
Take 3 samples on each of the two steel pipes for each batch
Take 1 sample on each of the two steel pipes for each batch
Take 1 sample on each of the two steel pipes for each batch
Steel pipes shall be inspected and accepted in batches. Each batch of steel pipes shall be of the same grade, The steel pipes are composed of the same furnace () number, the same specification and the same delivery status, and the number of sections in each batch shall not exceed 200. 6.3 Sampling quantity
The sampling quantity of each batch of copper pipes for various tests shall comply with the provisions of Table 5. 6.4 Re-inspection and judgment rules
The re-inspection and judgment rules of steel pipes shall comply with the provisions of GB/T2102 and GB/T17505. 7 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel pipes shall comply with the provisions of GB/T2102.5 Solidity
The solidity test of steel pipe can be carried out by hydraulic test or non-destructive testing, and the test method is selected by the supplier. 4.5.1 During the hydraulic test, the steel pipe shall not show leakage under the test pressure of 5MPa, and the test pressure shall be maintained for not less than 5s. 4.5.2 Non-destructive testing can be carried out by eddy current testing or magnetic leakage testing. Eddy current testing shall be carried out according to the acceptance level A of GB/T7735. Magnetic leakage testing shall be carried out according to L4 of GB/T12606. 4.6 Low-power inspection and non-metallic inclusion inspection 4.6.1 Steel pipes made directly from steel ingots shall be subject to low-power inspection. There shall be no visible white spots, inclusions, subcutaneous bubbles, skin folding and delamination on the aldehyde-impregnated test piece of the cross section of the steel pipe.
Steel pipes made directly from steel ingots and steel pipes made from continuous casting pipes shall be subject to non-metallic inclusion inspection. The non-metallic inclusions of steel pipes shall be rated according to the JK series rating chart in GB/T10561. A, B, C, D types of inclusions shall be judged according to the most serious ones, and the level shall not be greater than 2.5 levels respectively.
4.6.2 The low-power inspection of rolled (forged) pipes and the low-power inspection of non-metallic inclusions and the low-power inspection of continuous casting pipes shall be carried out on the pipes and shall comply with the provisions of YB/T5137.
4.7 Surface quality
GB1B248—2000
The inner and outer surfaces of steel pipes shall not have cracks, folds, rolling folds, delamination and scarring. These defects must be completely removed, the removed area should be smooth, and the removal depth shall not exceed the negative deviation of the nominal wall thickness. The actual wall thickness at the cleaned area shall not be less than the minimum value allowed by the wall thickness. Other local defects whose depth does not exceed the negative deviation of the wall thickness are allowed to exist. 4.8 Non-destructive testing
Copper tubes shall be subjected to ultrasonic flaw detection according to the provisions of GB/T5777. Cold-rolled (drawn) steel tubes shall be subjected to C5 grade, and hot-rolled steel tubes shall be negotiated by the supply and demand parties.
Steel tubes that have been hydraulically tested can be subjected to end magnetic flaw detection according to L2 of GB/T12606. 5 Test methods
5.1 The size and shape of steel tubes shall be measured one by one using measuring tools that meet the accuracy requirements. 5.2 The inner and outer surfaces of the steel tubes shall be visually inspected one by one under sufficient lighting conditions. Visual inspection, 5.3 Other inspections of steel pipes shall comply with the provisions of Table 5. Table 5 Inspection items, test methods and sampling quantity of steel pipes No.
Inspection items
Chemical composition
Tensile test
Impact test
Axillary pressure test
Eddy current flaw detection
Magnetic flux leakage flaw detection
Ultrasonic operation
Macro inspection
Non-metallic inclusion inspection
Inspection rules
6.1 Inspection and acceptance
Test method
GB/T 222,GB/T 223.GE/T 4336
GB/T 228
GB/T229
GB/T 241
GB/T7735
GB/T12606
GB/T 5777
GB/T 226.GB/T 1979
GB/T 10561
The inspection and acceptance of steel pipes shall be carried out by the supplier's technical supervision department. 6.2 Batch rules
Quantity of sampling
Take 1 sample for each expansion
Take 1 sample on each of the two steel pipes for each batch
Take 3 samples on each of the two steel pipes for each batch
Take 1 sample on each of the two steel pipes for each batch
Take 1 sample on each of the two steel pipes for each batch
Steel pipes shall be inspected and accepted in batches. Each batch of steel pipes shall be of the same grade, The steel pipes are composed of the same furnace () number, the same specification and the same delivery status, and the number of sections in each batch shall not exceed 200. 6.3 Sampling quantity
The sampling quantity of each batch of copper pipes for various tests shall comply with the provisions of Table 5. 6.4 Re-inspection and judgment rules
The re-inspection and judgment rules of steel pipes shall comply with the provisions of GB/T2102 and GB/T17505. 7 Packaging, marking and quality certificate
The packaging, marking and quality certificate of steel pipes shall comply with the provisions of GB/T2102.
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