The cause of uneven wall thickness of carbon steel seamless steel tube

- Jan 29, 2019-

Based on a plug mill rolling once anatomical analysis of steel seamless steel tube, assume perforation capillary once plug mill rolling, longitudinal and steel seamless steel tube wall thickness uneven stay for the most part within the sort of the perforation thickness uneven distribution of MAO, the steel seamless steel tube still have once rolling spiral of uneven thickness, and therefore the crosswise uneven wall thickness raised considerably.The reasons for the uneven wall thickness of automatic tube steel plant are as follows: (1) the shape and severity of the uneven wall thickness of perforated tubing directly have an effect on the form and severity of the uneven wall thickness of seamless steel tube of steel once rolling.(2) within the automatic steel plant on the pipe, as a result of the rod bending, so the highest position deviation from the middle of the opening and cause uneven wall thickness, the tube and tube head on the cross section of the utmost wall thickness and minimum wall thickness position is sort of fixed;However, the uneven degree of wall thickness from the top of the pipe to the end of the pipe will increase step by step. Therefore, reducing the residual bending degree of the ejector rod and therefore the axial force of the ejector rod throughout pipe rolling will considerably scale back the uneven degree of wall thickness.(3) the larger the wall reduction, the a lot of serious the uneven wall thickness of piping, the less the wall reduction, the automated tube rolling machine has the result of reducing the uneven wall thickness of perforated pipe.(4) hole adjustment isn't correct, once the roll seam uneven, can build the wall thickness of the pipe uneven aggravation.



For seamless steel seamless steel tube mill Φ four hundred millimeter automatic tube rolling unit, perforation, secondary perforation (extension), automatic tube rolling and rolling method are the four tubes measured wall thickness information of Fourier rework, it's all over that the measure of uneven wall thickness and its forming reasons, and on this basis, argue for up the steel seamless steel tube wall thickness uneven way:(1) the distribution characteristics of the coiling wall thickness uneven on the pipe once secondary perforation (extension) stay to the finished pipe, therefore up the secondary perforation (extension) is that the key to enhance the preciseness of the finished pipe wall thickness, the most live is to enhance the tool style, improve the disk shape of the rod and therefore the high and the rolling line within the rotation method.(2) improve the wall thickness of the capillary once perforation is a very important a part of the uneven, the most live is to enhance the heating uniformity of tube billet, improve the preciseness of centering hole, lengthen the length of the highest of the whole belt and therefore the length of the cone, improve the disk shape of the rod and therefore the high within the method of rotation and rolling line.(3) rolling pipe can turn out serious symmetry wall thickness, however to cut back the spiral wall thickness contains a sure role.Therefore, ought to be rolling 2 tube rolling, lane between tubes ought to be flip ninety °.(4) the total method will primarily eliminate the symmetry wall thickness difference, however to eliminate the role of the spiral wall thickness difference is incredibly little, therefore, ought to improve the power of the total machine.Fourier rework is a good technique to review the uneven wall thickness within the method of oblique rolling.


Cangzhou Steel Pipe Group (CSPG) Co., Ltd

Cangzhou Steel Pipe Group (CSPG) Co., Ltd. is a large-sized, key metallurgic enterprise of Hebei Province in North China, whose history dates back to 1994. CSPG currently em/paces six member companies with products varying from SSAW, LSAW, ERW, seamless steel pipes to 3PE pipes, galvanized pipes, casing pipes, etc. A Joint-stock corporation, CSPG occupies an area of 600,000 square meters with a total asset of $530 million.



Specialized in the production of straight welded pipe spiral pipe galvanized pipe 3PE/3PP/FBE/TPEP internal and external epoxy powder internal and external epoxy resin cement mortar two cloth three oil buried pipeline IPN8710 non-toxic drinking water internal and external plastic coated lining plastic and other anti-corrosion pipe fittings for oil and gas pipeline water conservancy projects



Executive standard :DIN30670 DIN30678 CSA Z245 AFNOR nf49-710/711 NACE rp0394/0490 AWWAC 210/C213GB/T9711 API 5L ISO 3183Material: Q235B/Q355BGR A GR B x42-x80 l245-l555

 

Business scope: 21.3mm-3620mmLSAW submerged arc welded pipe 325-2020mmERW straight welded pipe 6mm-711mmSMLS seamless tube 10-1120mmSSAW spiral steel tube 219-3620mmDemand for quality suppliers and partners



Types of Steel Pipe for Machine Structures
Product nameManufacturing methodMain features and applications
Carbon Steel Pipe for Machine StructuresThese products normally conform to JIS G 3445 Carbon Steel Tubes for Machine Structural Purposes. 
We also manufacture such carbon steel pipe products using materials that conform to JIS G 4051 Steel for Machine Structural Purposes, as well as to other standards and specifications.
These steel pipe products are used in machines, automobiles, bicycles, furniture, tools and utensils, and other machine parts.
Alloy Steel Pipe for Machine StructuresThese products normally conform to JIS G 3441 Alloy Steel Tubes for Machine Structure Purposes, but we also manufacture such alloy steel pipe products using materials that conform to JIS G 4053 Low-Alloyed Steels for Machine Structural Use, as well as to other standards and specifications.These steel pipe products are used in machines, automobiles, and other machine parts.
ERW Carbon Steel Pipe for Machine StructuresThese products are manufactured based on JIS G 3472 Electric Resistance Welded Carbon Steel Tubes for Automobile Structural Purposes.They are used mainly in automotive machine parts.
High-Strength Steel Pipe for Machine StructuresThese steel pipe products, include seamless steel pipe, ERW steel pipe, and hot finished ERW steel pipe.They are used in marine structures and cylinders for their excellent weldability and low-temperature properties, and in machine parts for reduced weight and increased strength.


TypeSignalTensile testing
Tensile strength
kg/㎟
(MIN)
Yield point
kg/㎟
(MIN)
Elongation(%) (MIN)
Grade 11 Test piece
Grade 12 Test piece
Longitudinal
Grade 5 Test piece
transverse
11 TypeASTKM11A30 or more-35 or more30 or more
12 TypeASTKM12A35 or more18 or more35 or more30 or more
BSTKM12B40 or more28 or more25 or more20 or more
CSTKM12C48 or more36 or more20 or more15 or more
13 TypeASTKM13A38 or more22 or more30 or more25 or more
BSTKM13B45 or more31 or more20 or more15 or more
CSTKM13C52 or more39 or more15 or more10 or more
14 TypeASTKM14A42 or more25 or more25 or more20 or more
BSTKM14B51 or more36 or more15 or more10 or more
CSTKM14C56 or more42 or more15 or more10 or more
15 TypeASTKM15A48 or more28 or more22 or more17 or more
CSTKM15C59 or more44 or more12 or more7 or more
16 TypeASTKM16A52 or more33 or more20 or more15 or more
CSTKM16C63 or more47 or more12 or more7 or more
17 TypeASTKM17A56 or more35 or more20 or more15 or more
CSTKM17C66 or more49 or more10 or more5 or more
18 TypeASTKM18A45 or more28 or more25 or more20 or more
BSTKM18B50 or more32 or more23or more18or more
CSTKM18C52 or more39 or more15 or more10 or more
19 TypeASTKM19A50 or more32 or more23 or more18 or more
CSTKM19C56 or more42 or more15 or more10 or more
20 TypeASTKM20A55 or more40 or more23 or more18 or more


TypeSignalTensile testingIntended use
CSiMnPS
11 Type A STKM11A0.12 Less than0.35 Less than0.60 Less than0.040 Less than0.040 Less thanStarter Motor Yoke General use
12 TypeASTKM12A0.200.350.600.0400.040

Cross Member
Jack Propeller Shaft
The Rod

BSTKM12B
CSTKM12C
13 TypeASTKM13A0.250.350.30~0.900.0400.040Propeller Shaft
Steering Shaft
Oil pressure Cylinder, Axle Tube
BSTKM13B
CSTKM13C
14 TypeASTKM14A0.300.350.30~1.000.0400.040Oil pressure Cylinder
Axle Tube
BSTKM14B
CSTKM14C
15 TypeASTKM15A0.25~0.350.350.35~1.000.0400.040Extensing Tube
Cross Member
CSTKM15C
16 TypeASTKM16A0.35~0.450.400.40~1.000.0400.040Rocker Arm Tube
Axle Tube Steering System
CSTKM16C
17 TypeASTKM17A0.45~0.550.400.40~1.000.0400.040Boring Rod
Axle Tube
CSTKM17C
18 TypeASTKM18A0.180.551.500.0400.040Hydraulic prop
Fork Tube
Boom Repeated oil pressure Cylinder
BSTKM18B
CSTKM18C
19 TypeASTKM19A0.250.551.500.0400.040
CSTKM19C
20 TypeASTKM20A0.250.551.600.0400.040


DivisionTolerance for outer diameter
No. 150mm Less than
50mm or more

±0.5mm
±1%
No. 250mm Less than
50mm or more

±0.25mm
±0.5%
No. 325mm Less than
25mm or more
40mm or more
50mm or more
60mm or more
70mm or more
80mm or more
90mm or more
100mm or more 
40mm Less than
50mm Less than
60mm Less than
70mm Less than
80mm Less than
90mm Less than
100mm Less than
±0.12mm
±0.15mm
±0.18mm
±0.20mm
±0.23mm
±0.25mm
±0.30mm
±0.40mm
±0.50%
Steel Pipe for Building Structures

Advanced, high-performance steel pipe that can be found on almost any construction site.

In addition to delivering its highly trusted JIS-compliant steel pipe for building structures (e.g., STK and STKR) for a long time. In addition, we engage constantly and actively in R&D, so that we can deliver even more advanced and capable materials.

Tolerance:
Steel typePipe Out diameter
(D)
Pipe wall thickness
(S)
Cold Drawing PipeO.D.
(mm)
Tolerance
(mm)
W.T.
(mm)
Tolerance
(mm)
>30~50±0.3≤30±10%
>50~219±0.8%
Hot Rolled Pipe>219±1.0%>20±10%
Mechanical properties:
StandardGradeTensile Strength
(MPa)
Yield strength
(MPa)
elongation
(%)
GB/T816210≥335≥205≥24
20≥390≥245≥20
35≥510≥305≥17
45≥590≥335≥14
Q345≥490≥325≥21
15CrMo≥440≥295≥22
12Cr1MoV≥490≥245≥22
ASTM A53
ASME SA53
A≥330≥205查看ASTM A53的表


查看ASME SA53的表
B≥415≥240
Chemical composition:
StandardGradeComposition(%)
CSiMnPSCuNiMoCrV
GB/T8162100.07~0.140.17~0.370.35~0.65≤0.035≤0.035≤0.25≤0.25/≤0.15/
200.17~0.240.17~0.370.35~0.65≤0.035≤0.035≤0.25≤0.25/≤0.25/
350.32~0.400.17~0.370.50~0.80≤0.035≤0.035≤0.25≤0.25/≤0.25/
450.42~0.500.17~0.370.50~0.80≤0.035≤0.035≤0.25≤0.25/≤0.25/
Q3450.12~0.200.20~0.551.20~1.60≤0.035≤0.035≤0.25≤0.25/≤0.25/
15CrMo0.12~0.180.17~0.370.40~0.70≤0.035≤0.035≤0.25≤0.300.40~0.550.80~1.10/
12Cr1MoV0.08~0.150.17~0.370.40~0.70≤0.035≤0.035≤0.25≤0.300.25~0.350.90~1.200.15~0.30
ASTMA53
ASMESA53
A≤0.25/≤0.95≤0.05≤0.06≤0.40≤0.40≤0.15≤0.40≤0.08
B≤0.30/≤1.20≤0.05≤0.06≤0.40≤0.40≤0.15≤0.40≤0.08