This standard specifies the classification and code, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of cold-drawn or cold-rolled precision seamless steel tubes. This standard is applicable to the manufacture of cold-drawn or cold-rolled precision seamless steel tubes with special dimensional accuracy and high surface quality requirements for mechanical structures, hydraulic equipment, and automobiles. GB/T 3639-2000 Cold-drawn or cold-rolled precision seamless steel tubes GB/T3639-2000 standard download decompression password: www.bzxz.net

GB/T3639--2000
This standard adopts the German DIN2391/1-1994 "Precision Seamless Steel Tubes with Special Precision" and DIN2391/2-1994 "Technical Conditions for Supply of Precision Seamless Steel Tubes with Special Dimensional Precision" standards. The main difference is that this standard does not directly include the terms of quality grade C, but is given in other requirements, which are determined by negotiation between the supply and demand parties. This standard has revised the scope of application and classification code of the original national standard, added terms such as ellipticity and uneven wall thickness, density, surface roughness, and added two delivery states of annealing and normalizing. And the mechanical properties of the two delivery states of annealing and normalizing are specified. This standard replaces GB/T3639-1983 "Cold-drawn or Cold-rolled Precision Seamless Steel Tubes" from the date of implementation. This standard is proposed by the State Bureau of Metallurgical Industry. This standard is under the jurisdiction of the National Technical Committee for Steel Standardization. The drafting unit of this standard: Shanghai Steel Pipe Co., Ltd. The main drafters of this standard are Zhang Yaofei, Li Fuliang, Luo Yuqing and Yuan Weiming. This standard was first issued in 1983.
1 Scope
National Standard of the People's Republic of China
Cold-drawn or
cold-rolled precision seamless steel tubesGB/T 3639--2000
Replaces GB/T3639-1983
This standard specifies the classification and code, size, shape, weight and allowable deviation, technical requirements, test methods, inspection rules, packaging, marking and quality certificate of cold-drawn or cold-rolled precision seamless steel tubes. This standard is applicable to the manufacture of cold-drawn or cold-rolled precision seamless steel tubes with special dimensional accuracy and high surface quality requirements for mechanical structures, hydraulic equipment and automobiles.
2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of this standard, the versions shown are 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/T222-1984 Sampling method for chemical analysis of steel and allowable deviation of chemical composition of finished products GB/T223.5-1997 Chemical analysis methods for steel and alloys - Determination of acid-soluble silicon content by reduced molybdenum silicate photometric method GB/T 223.12-1991
GB/T 223.23-1994
GB/T 223. 27---1994
GB/T 223. 59-1987
GB/T 223. 63-1988
GB/T 223.68-1997
GB/T 223. 69-—1997
GB/T 228-—1987
Methods for Chemical Analysis of Iron, Steel and Alloys Sodium Carbonate Separation-Diphenylcarbazide Photometric Determination of Chromium Content Methods for Chemical Analysis of Iron, Steel and Alloys
Diacetyl Spectrophotometric Determination of Nickel Content
Methods for Chemical Analysis of Iron, Steel and Alloys
Thiocyanate-Butyl Acetate Extraction Spectrophotometric Determination of Molybdenum Content Antimony Phosphorus Molybdenum Blue Photometric Determination of Phosphorus 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
Methods for Chemical Analysis of Iron, Steel and Alloys
Methods for Metal Tensile Testing
GB/T 699—1999
GB/T 1031-1995
GB/T 2102-—1988
GB/T 4336--1984
GB/T 7735—1995
High-quality carbon structural steel
Surface roughness parameters and their values
Determination of manganese content by sodium (potassium) periodate photometryDetermination of sulfur content by potassium iodate titration after combustion in a tubular furnaceDetermination of carbon content by gas volumetric method after combustion in a tubular furnaceAcceptance, packaging, marking and quality certificate of steel pipesPhotoelectric spectroscopic analysis method for carbon steel and medium and low alloy steelsEddy current flaw detection method for steel pipes
Dimensions, shape, weight and tolerances of seamless steel pipesGB/T 17395—1998
GB/T 17505---1998
YB/T5222—1993
3 Classification and code
General technical requirements for delivery of steel and steel products
High-quality carbon steel round tube
Steel tubes are divided according to delivery status (codes in brackets): cold worked/hard (BK), cold worked/soft (BKW), stress relief annealing after cold working (BKS), annealing (GBK), and normalizing (NBK). 4 Dimensions, shape, weight and allowable deviations
4.1 Diameter and wall thickness
4.1.1 The diameter and wall thickness of the steel pipe shall conform to the provisions of Table 1. Approved by the State Administration of Quality and Technical Supervision on October 25, 2000 and implemented on September 1, 2001
Allowable deviation
3±0.302.4±0.30
4±0.303. 4±0.30
4.4±0.25
6.4±0.20
GB/T 3639 --2000
3.6±0.30
5.6±0.30
8.4±0.15
7.6±0.25
10.4±0.1510±0.159.6±0.20
4. 4±0. 354±0. 353.6±0.406.4±0.30
8.4±0.25
11.4±0.1511±0.1510.6±0.2010±0.20
9.4±0.25
13±0.1012.4±0.10
12±0.1011.6±0.15
14.4±0.10
10.4±0.20
12.4±0.1512±0.15
14±0.1013.6±0.10
17±0. 10 16. 4±0. 101
16±0.1015.6±0.10
14.4±0.101
5.6±0.35
7.5±0.30
8.6±0.30
9. 6±0. 25
11.6±0.20
13.6±0.20
Wall thickness ±10%
(nominal value and
7±0.306.4±0.406±0.40
7.4±0.40||t t||8.4±0.30
11±0.2010.4±0.30
13±0.2012.4±0.20
15±0.1514.4±0.1514±0.20
19±0.1018. 4±0. 10
18±0. 1017. 6±0. 10
16.4±0.1016±0.1015.6±0.1517±0.10
21±0. 1020. 4±0.102
19.6±0.10
19±0.1018.4±0.1018±0.10
17±0.1516.4±0 .15
17.6±0.10
021.4±0.1021±0.1020.6±0.1020±0.1019.4±0.1524±0. 1023.4±0.10
23±0.1022.0±0.122±0.10
25±0. 10 24. 4±0. 10 24±0. 10 23. 6±0. 1023±0.1022.4±0.1022±0.10
27±0.1026.4±0.10 26±0.1025.6±0.1021.6±0.1021±0.1020.4±0.1520±0.1523.6±0.1023±0.10|22.4±0.1022±0.1525±0.10.24.4±0.102 4±0.10
29±0.1028.4±0.1028±0.1027.6±0.1027±0.1026.4±0.1026±0.1031±0.1530.4±0.1530±0.15
29.6±0.15
34±0.1533.4±0.15
37±0.1536.4±0.15
39±0.1538.4±0.15
29±0. 15 28 . 4±0. 15
32. 6± 0. 15 32±0. 15
±0, 15
35.6±0.1535±0.15
37.6±0.1537±0.15
36.4±0.15
28±0 . 15
31±0,15
34±0. 15 | | tt | |tt||33. 6±0. 1
33±0.1532.4±0.1532±0.15
35±0.1534.4±0.1534±0.15
35.6±0.15
39.6±0.2039±0.2038.4± 0.2037.6±0.20 37±0.2036.4±0.2036±0.2038±0.20
42. 6±0. 20 42±0. 20 41. 4±0. 20|46±0.2045.6±0.20 45±0.2044.4±0.2040.6±0.2040±0.2039.4±0.2039±0.2041±0.20
43.6± 0.2043±0.2042.4±0.2042±0.2044±0.20
48±0.2047.6±0.2047±0.2046.4 ±0.2045.6±0.2045±0.2044.4±0.2044±0.2046±0.20k
52.6±0.2552±0.2 551.4±0.2551±8.2550.6±0.2550±0.2549.4±0.2549±0.2553±0.25
56±0. 25 55.6±0.2555±0.2554. 4±0.2554±0.2557.6±0.2557±0.2556.4±0.2558±0.25
0 |60. 6±0. 30 60±0. 30 59. 4±0. 3059±0.3058.6±0.3058±0.3057.4±0.3057±0.3061±0.30
66±0.3065.6±0 .3065±0.3064.4±0.3068±0.3067.6±0.3067±0.30
66.4±0.30
74±0. 35 73. 6±0. 35 73±0. 35 72. 4±0. 3572±0.3571.6±0.3571±0.3570.4±0.3570±0.3578±0. 3577.6±0. 3577±0.3576.4±0.3576±0.3575. 6±0.3575±0.3574.4±0.3574±0.3587±0. 40:86. 4±0.40
96.4±0.45
Note: the dimensions in brackets are not recommended
86± 0.4085.6±0.40 85±0.4084.4±0.4084±0.4096±0.4595.6±0.4595±0.4594.4±0.4594±0.45106±.0.50
105.6±0.50105±0.50104.4±0.50116±0 .50115.6±0.50|115±0.50114.4±0.50104±0.50
114±0.50
124±0.65
134±0.65
144±0.75||tt| |(min ±0.12 mm)
allowable deviation)
11±0.3510±0.35
68±0.3567±0.35
72±0.3571±0.35
103±0.50102±0.50
113±0.50|112±0.50
123±0.65
133±0.65| |tt||122±0.65
132±0.65
143±0.75
142±0.75
152±0.80||tt| |101±0.50100±0.5099±0.50
111±0.50110±0.50109±0.50
121±0.65120±0. 65119±0. 65131±0.65
141±0.75
151±0.80
162±0.85
161±0.85
130±0.65
129± 0.65
140±0.75
139±0.75
150±0.80
149±0.80
160±0.85
159±0.85
170±0.90|| tt||169±0.90
GB/T 3639—2000
108±0.50
118±0.65
128±0.65
138±0.75
148±0.80
158± 0,85
168±0.90
178±0.95
106±0.50
116±0.65
126±0.65
136±0.75
146± 0.80
1 56±0.85
166±0.90
176±0.95
104±0.50
114±0.65
124±0.65
-82 ±0.45
10 2±0.50
112±0.65
100±0.50
110±0.65
122±0.65120±0.65
134±0.75
132±0.7513 0±0.75
144±0.80
154±0.85
164±0.90
174±0.95
142±0.80
152± 0.85
162 ±0.90
172±0.95
140±0.80
150±0.85
160±0.90
170±0.95
108±0.65
118± 0.65
128±0.75
138±0.80
148±0.85
158±0.90
168±0.95
105±0.65| |tt||115±0 .65
125±0.75
135±0.80
145±0.85
155±0.90
165±0.95
4.1.2 Diameter allowable deviation
GB/T 36392
4.1.2.1 The allowable deviations of the outer and inner diameters of steel tubes in the cold worked/hard (BK) state and the cold worked/soft (BKW) state shall comply with the provisions of Table 1.
4.1.2.2 The allowable deviation of the outer diameter and inner diameter of steel pipes in the state of stress relief annealing (BKS), annealing (GBK) and normalizing (NBK) after cold working shall comply with the provisions of Table 2.
Allowable deviation of the outer diameter and inner diameter of steel pipes in heat treatment state Wall thickness (S)/outer diameter (D)
S/D≥1/20
1/40≤S/D1/20
S/D≤1/40
4.1.3 The allowable deviation of the wall thickness of steel pipes shall comply with the provisions of Table 1. Allowable deviation
According to the value specified in Table 1
According to 1.5 times the value specified in Table 1
According to 2.0 times the value specified in Table 1
4.1.4 Steel pipes are usually supplied with outer diameter and wall thickness. When the purchaser requires the supply of outer diameter and inner diameter or inner diameter and wall thickness, it should be indicated in the contract. 4.1.5 According to the requirements of the purchaser, after negotiation between the supply and demand parties and indicated in the contract, steel pipes with specifications and allowable deviations other than those in Table 1 can be provided. 4.2 Length
4.2.1 Normal length
The normal length of steel pipes is 2000～7000mm. 4.2.2 Fixed length and multiple lengths
The fixed length and multiple lengths of steel pipes should be within the normal length range, and the allowable deviation of the full length should comply with the following provisions: Length ≤5000mm
Length>5 000 mm
For steel pipes delivered with multiple lengths, each multiple length should have a cut margin according to the following provisions: For outer diameter ≤159mm25~10mm,
For outer diameter>159mm210~15mm.
4.2.3 According to the requirements of the purchaser, after negotiation between the supply and demand parties and indicated in the contract, steel pipes with other lengths and allowable deviations can be provided. 4.3 Curvature
The curvature of the steel pipe in the cold-worked/hard (BK) state and the cold-worked/soft (BKW) state shall not exceed 3.0mm/m; the curvature of the steel pipe in the cold-worked stress-relief annealing (BKS) state, annealing (GBK) state, and normalizing (NBK) state shall not exceed 1.5mm/m. 4.4 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. 4.5 Ovality and uneven wall thickness
4.5.1 The ovality of the steel pipe shall not exceed 80% of the outer diameter tolerance; 4.5.2 According to the requirements of the buyer, the uneven wall thickness of the steel pipe shall be negotiated by the supply and demand parties. 4.6 Weight
The delivery weight of the steel pipe shall comply with the provisions of GB/T17395. The density of steel is 7.85kg/dm2. When the steel pipe is delivered by theoretical weight, the allowable deviation between the actual weight of the delivered steel pipe and the theoretical weight shall comply with the following provisions according to the requirements of the purchaser, after consultation between the supply and demand parties and indicated in the contract: ±8% for a single steel pipe, ±7.5% for a batch of steel pipes with a minimum of 10 tons; 4.7 Marking example
The outer diameter of 50mm, the inner diameter of 30mm, and the cold-worked/hardened cold-rolled precision seamless steel pipe made of 20 steel is marked as: Finished 20-$50×$30BK-GB/T3639-2000 The outer diameter of 38mm, the wall thickness of 3mm, the cut length of 5000mm, and the cold-worked/softened cold-rolled precision seamless steel pipe made of 10 steel is marked as:
GB/T 3639—2000
Fine rolling 10-$38×3×5000BKW-GB/T3639—2000The cold drawn precision seamless steel pipe made of 35 steel with an inner diameter of 30mm, a wall thickness of 2mm, a multiple length of 1800mm, and a stress relief annealing state is marked as:
Fine drawing 35-inner $30×2×1800 times BKS-GB/T3639—20005 Technical requirements
5.1 Steel grade and chemical composition
5.1.1 Steel pipes are made of 10, 20, 35, and 45 steels, and their chemical composition shall comply with the provisions of GB/T699. The steel pipes are accepted according to the smelting composition. 5.1.2 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 shall comply with the provisions of GB/T222.
5.1.3 According to the requirements of the purchaser, after negotiation between the supply and demand parties, other grades of high-quality carbon structural steel and alloy structural steel pipes can be provided. 5.2 Manufacturing method
5.2.1 The steel smelting method shall be selected by the manufacturer. 5.2.2 Round pipes shall comply with the provisions of YB/T5222. 5.2.3 Steel pipes are manufactured by cold drawing or cold rolling. When the purchaser specifies a certain method for manufacturing steel pipes, it shall be indicated in the contract. 5.3 Delivery status
Steel pipes are delivered in the states listed in Table 3.
Table 3 Delivery status
Delivery status
Cold working/hard
Cold working/soft
After cold working
Stress relief annealing
5.4 Mechanical properties
No heat treatment is performed after the final cold working, so the pipe may only be deformed very slightly. After the final heat treatment, cold working with a small deformation amount is performed, and limited cold deformation (for example: bending, expanding) is allowed during reprocessing of the steel pipe.
Annealing is performed below the Ac1 point after the final cold working to eliminate cold working stress. After the final cold working, the steel pipe is fully annealed under protective gas. After the final cold working, the steel pipe is normalized under protective gas. The mechanical properties of the steel pipe shall comply with the provisions of Table 4. Table 4 Mechanical properties
Delivery condition
Elongation
Elongation
Elongation
Elongation
Note: For steel pipes with an outer diameter not exceeding 30 mm and a wall thickness exceeding 3 mm, the minimum yield point can be reduced by 10 MPa Tensile strength
Service point
Elongation
GB/T 3639—2000
5.4.2 The mechanical properties of other grades of steel pipes shall be negotiated by the supply and demand parties. 5.5 Compactness
According to the requirements of the purchaser, after negotiation between the supply and demand parties and indicated in the contract, the steel pipes delivered in the state of stress relief annealing (BKS), annealing (GBK), and normalizing (NBK) after cold working can be tested for compactness. The compactness test shall be carried out by eddy current flaw detection in accordance with the provisions of acceptance level A of GB/T7735.
5.6 Surface roughness
When the purchaser has roughness requirements for the steel pipe surface, it should be indicated in the contract. The surface roughness parameters are measured according to the arithmetic mean deviation Ra of the profile specified in GB/T1031. The surface roughness value and the sampling length value during the measurement shall be negotiated by the supply and demand parties. 5.7 Surface quality
The inner and outer surfaces of the steel pipe should be smooth, and the depth of local pits, scratches and fine scratches should not exceed 0.08mm. The actual wall thickness of the steel pipe at these defects should not be less than the minimum value allowed by the wall thickness deviation. Other defects on the inner and outer surfaces of the steel pipe can be removed by appropriate methods. After removal, the actual wall thickness of the steel pipe should not be less than the minimum value allowed by the wall thickness deviation.
The inner and outer surfaces of the steel pipe delivered in the cold working state are allowed to have phosphate and lubricant adhesion layers from the manufacturing process. The inner and outer surfaces of the steel pipe delivered in the heat treatment state are allowed to have an oxide film layer that does not affect the surface inspection, but there should be no loose oxide scale. 5.8 Other requirements bzxZ.net
When the purchaser has requirements beyond the requirements of this standard and other additional conditions, the supply and demand parties shall negotiate and indicate them in the contract. 6 Test methods
6.1 The size and shape of the steel pipe shall be measured and inspected one by one using measuring tools with appropriate accuracy. 6.2 The inner and outer surfaces of the steel pipe shall be visually inspected one by one under sufficient lighting conditions. 6.3 Other inspections
The test methods for 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 Serial number
7 Inspection rules
7.1 Inspection and acceptance
Inspection items
Chemical composition
Tensile test
Solidity test
Surface roughness inspection
Test method
GB/T 222
GB/T223
GB/T4336
GB/T228
GB/T7735
GB/T1031
Sampling quantity
1 specimen for each heat ()
1 specimen for each batch
Take 1 specimen from each of the 2 steel pipes in each batch
The inspection and acceptance of steel pipes shall be carried out by the supplier’s technical supervision department. The inspection and acceptance of steel pipes shall comply with the provisions of GB/T2102, except for those already specified in this standard.
7.2 Batch rules
Steel pipes shall be inspected and accepted in batches. Each batch shall consist of steel pipes of the same brand, furnace (tank) number, specification and delivery status. The number of steel pipes in each batch shall not exceed 200. 7.3 Sampling quantity
The sampling quantity for each inspection of steel pipes shall comply with the provisions of Table 5. 118
7.4. Judgment and re-inspection rules
GB/T3639—2000
The judgment and re-inspection rules of steel pipes shall comply with the provisions of GB/T2102 and GB/T17505. 8.|tt||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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