China OEM China Wholesale Seamless Steel Pipe
Our company is mainly engaged in the export business of seamless steel tubes, China Steel Tube, chinese SMLS, Seamless Steel Pipes, Seamless steel tubes, SMLS, SMLS China, SMLS structure pipes.
Several main models of hot rolled seamless steel tube production
1, Hot rolled steel pipes
become the mainstream model for seamless steel pipe production. Multi-stand continuous pipe rolling technology.
Compared with other models, the continuous rolling mill has become the first choice for the world’s major seamless steel tube production enterprises due to its high quality, high output, high efficiency, and low consumption.
2, 3 roll continuous pipe rolling mill
opened a new era of continuous rolling steel pipe technology
Since 2005, there have been more than 20 sets of 3-roll continuous rolling mills that have been built and are under construction worldwide. The construction of these rolling mills has created a new era of 3-roll continuous rolling steel pipe technology.
3. Automatic pipe rolling machine, also known as Plug mill
Among them, large and medium-sized automatic pipe rolling mills still play an important role after technical transformation.
4. Periodic pipe rolling mill, also known as Pilger mill
is suitable for the production of medium and thick wall large and medium caliber steel pipes. It is one of the oldest models in the world
Due to the low production efficiency and poor external surface quality of this mill, its production cost and product quality are difficult to compete with other mills. Most of the small and medium-caliber mills have been eliminated. Large-scale periodic tube rolling mill still has an advantage in the production of large-diameter thick-walled steel tubes, especially for the production of large-diameter thick-wall power station tubes. Periodic tube rolling mills are still an effective method, so they are retained.
5. Precision tube rolling machine, 3-roll tube rolling machine
The precision tube rolling machine is also called Accu2Roll tube rolling machine, and the 3-roll tube rolling machine is also called Assel tube rolling machine. It is also a seamless steel tube rolling mill with high rolling accuracy. The configuration of the front and back processes is basically the same as the Accu2Roll tube mill except that the stretcher uses 3-roll cross-rolling.
6. Other tube rolling machines
Except for China, extruders, large-diameter pipe jacking machines, and large-diameter skew rolling and expanding machines have little new development in other countries in the world. In China, due to the rapid development of seamless steel pipe production and the demand for high-end products, the construction of these rolling mills has also made new developments.
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Overview
Application
It Is Mainly Used To Make Carbon Structural Steel, Alloy Structural Steel and mechanical structures.
Main Grade
Grade Of Carbon Structural Steel: 10,20,35, 45,Q345,Q460,Q490,Q620,, Etc
Grade Of Alloy Structural Steel: 42CrMo,35CrMo, Etc
Chemical Component
Steel Grade |
Quality level |
Chemical composition |
||||||||||||||
C |
Si |
Mn |
P |
S |
Nb |
V |
Ti |
Cr |
Ni |
Cu |
Nd |
Mo |
B |
Als” |
||
no greater than |
not less than |
|||||||||||||||
Q345 | A |
0.20 |
0.50 |
1.70 |
0.035 | 0.035 |
0.30 |
0.50 |
0.20 |
0.012 |
0.10 |
—— | — | |||
B | 0.035 | 0.035 | ||||||||||||||
C | 0.030 | 0.030 |
0.07 |
0.15 |
0.20 |
0.015 |
||||||||||
D |
0.18 |
0.030 | 0.025 | |||||||||||||
E | 0.025 | 0.020 | ||||||||||||||
Q390 | A |
0.20 |
0.50 |
1.70 |
0.035 | 0.035 |
0.07 |
0.20 |
0.20 |
0.3 |
0.50 |
0.20 |
0.015 |
0.10 |
— | — |
B | 0.035 | 0.035 | ||||||||||||||
C | 0.030 | 0.030 |
0,015 |
|||||||||||||
D | 0.030 | 0.025 | ||||||||||||||
E | 0.025 | 0.020 | ||||||||||||||
Q42O | A |
0.20 |
0.50 |
1.70 |
0.035 | 0.035 |
0.07 |
0.2 |
0.20 |
0.30 |
0.80 |
0.20 |
0.015 |
0.20 |
—— |
—— |
B | 0.035 | 0.035 | ||||||||||||||
C | 0.030 | 0.030 |
0.015 |
|||||||||||||
D | 0.030 | 0.025 | ||||||||||||||
E | 0.025 | 0.020 | ||||||||||||||
Q46O | C |
0.20 |
0.60 |
1.80 |
0.030 | 0.030 |
0.11 |
0.20 |
0.20 |
0.30 |
0.80 |
0.20 |
0.015 |
0.20 |
0.005 |
0.015 |
D | 0.030 | 0.025 | ||||||||||||||
E | 0.025 | 0.020 | ||||||||||||||
Q500 | C |
0J8 |
0.60 |
1.80 |
0.025 | 0.020 |
0.11 |
0.20 |
0.20 |
0.60 |
0.80 |
0.20 |
0.015 |
0.20 |
0.005 |
0.015 |
D | 0.025 | 0.015 | ||||||||||||||
E | 0.020 | 0.010 | ||||||||||||||
Q550 | C |
0.18 |
0.60 |
2.00 |
0.025 | 0,020 | 0.11 |
0.20 |
0.20 |
0.80 |
0.80 |
0.20 |
0.015 |
0.30 |
0.005 |
0.015 |
D | 0.025 | 0,015 | ||||||||||||||
E | 0.020 | 0.010 | ||||||||||||||
Q62O | C |
0.18 |
0.60 |
2.00 |
0.025 | 0.020 |
0.11 |
0.20 |
0.20 |
1.00 |
0.80 |
0.20 |
0.015 |
0.30 |
0.005 |
0.015 |
D | 0.025 | 0.015 | ||||||||||||||
E | 0.020 | 0.010 | ||||||||||||||
a. In addition to Q345A and Q345B grades, the steel should contain at least one of the refined grain elements Al, Nb, V, and Ti. According to the needs, the supplier can add one or more refined grain elements. The maximum value shall be as specified in the table. When combined, Nb + V + Ti is not more than 0.22%b. For Q345, Q390, Q420 and Q46O grades, Mo + Cr is not greater than 0.30%c. When Cr and Ni of each grade are used as residual elements, the content of Cr and Ni should not be greater than 0.30%; when it is necessary to add, the content should meet the requirements in the table or be determined by the supplier and the buyer through consultation.d. If the supplier can ensure that the nitrogen content meets the requirements in the table, the nitrogen content analysis may not be performed. If Al, Nb, V, Ti and other alloy elements with nitrogen fixation are added to the steel, the nitrogen content is not limited. The nitrogen fixation content should be specified in the quality certificate.e. When using full aluminum, the total aluminum content Alt ≥ 0020%. |
Grade |
Carbon equivalent CEV (mass fraction) /% |
|||||
Nominal wall thickness s≤ 16mm |
Nominal wall thickness S2>16 mm〜30 mm |
Nominal wall thickness S>30mm |
||||
Hot rolled or normalized normalized |
Quenching +tempering |
Hot rolled or normalized |
Quenching +tempering |
Hot rolled or normalized |
Quenching +tempering |
|
Q345 |
<0.45 |
— |
<0.47 |
— |
<0.48 |
一 |
Q390 |
<0.46 |
一 |
W0.48 |
— |
<0.49 |
— |
Q420 |
<0.48 |
一 |
<0.50 |
<0.48 |
<0.52 |
<0,48 |
Q460 |
<0.53 |
<0.48 |
W0.55 |
<0.50 |
<0.55 |
W0.50 |
Q500 |
一 |
<0.48 |
一 |
<0.50 |
一 |
W0.50 |
Q550 |
— |
<0.48 |
.一 |
<0.50 |
一 |
<0.50 |
Q62O |
— |
<0.50 |
— |
<0.52 |
— |
W0.52 |
Q690 |
— |
<0.50 |
— |
<0.52 |
— |
W0.52 |
Mechanical Property
Mechanical properties of high-quality carbon steel structural steel and low-alloy high-strength structural steel pipes
Grade | Quality level | Yield Strength | Lower yield strength | Elongation after breaking | Impact test | |||
Nominal wall thickness | temperature | Absorb energy | ||||||
<16 mm | >16 mm〜 | 〉30 mm | ||||||
30 mm | ||||||||
not less than | not less than | |||||||
10 | — | >335 | 205 | 195 | 185 | 24 | — | — |
15 | — | >375 | 225 | 215 | 205 | 22 | — | 一 |
20 | —— | >410 | 245 | 235 | 225 | 20 | — | — |
25 | — | >450 | 275 | 265 | 255 | 18 | — | — |
35 | — | >510 | 305 | 295 | 285 | 17 | 一 | — |
45 | — | 2590 | 335 | 325 | 315 | 14 | — | — |
20Mn | —• | >450 | 275 | 265 | 255 | 20 | — | 一 |
25Mn | — | >490 | 295 | 285 | 275 | 18 | — | — |
Q345 | A | 470—630 | 345 | 325 | 295 | 20 | — | 一 |
B | 4~20 | 34 | ||||||
C | 21 | 0 | ||||||
D | -20 | |||||||
E | -40 | 27 | ||||||
Q39O | A | 490—650 | 390 | 370 | 350 | 18 | ||
B | 20 | 34 | ||||||
C | 19 | 0 | ||||||
D | -20 | |||||||
E | -40 | 27 | ||||||
Q42O | A | 520〜680 | 420 | 400 | 380 | 18 | ||
B | 20 | 34 | ||||||
C | 19 | 0 | ||||||
D | -20 | |||||||
E | -40 | 27 | ||||||
Q46O | C | 550〜720 | 460 | 440 | 420 | 17 | 0 | 34 |
D | -20 | |||||||
E | -40 | 27 | ||||||
Q500 | C | 610〜770 | 500 | 480 | 440 | 17 | 0 | 55 |
D | -20 | 47 | ||||||
E | -40 | 31 | ||||||
Q550 | C | 670〜830 | 550 | 530 | 490 | 16 | 0 | 55 |
D | -20 | 47 | ||||||
E | -40 | 31 | ||||||
Q62O | C | 710〜880 | 620 | 590 | 550 | 15 | 0 | 55 |
D | -20 | 47 | ||||||
E | -40 | 31 | ||||||
Q690 | C | 770〜94。 | 690 | 660 | 620 | 14 | 0 | 55 |
D | -20 | 47 | ||||||
E | -40 | 31 |
Mechanical properties of alloy steel pipes
NO | Grade | Recommended heat treatment regime | Tensile properties | Annealed or high temperature tempered steel pipe Delivery condition Brinell hardness HBW | ||||||
Quenching (normalizing) | Tempering | Yield StrengthMPa | Tensile Strength MPa | Elongation after breaking A% | ||||||
temperature | Coolant | Temperature | Coolant | |||||||
Frirst | Second | not less than | no greater than | |||||||
1 | 40Mn2 | 840 | Water, oil | 540 | Water, oil | 885 | 735 | 12 | 217 | |
2 | 45Mn2 | 840 | Water,oil | 550 | Water, oil | 885 | 735 | 10 | 217 | |
3 | 27SiMn | 920 | Water | 450 | Water, oil | 980 | 835 | 12 | 217 | |
4 | 40MnBc | 850 | oil | 500 | Water, oil | 980 | 785 | 10 | 207 | |
5 | 45MnBc | 840 | oil | 500 | Water, oil | 1 030 | 835 | 9 | 217 | |
6 | 20Mn2Bc’f | 880 | oil | 200 | Water, air | 980 | 785 | 10 | 187 | |
7 | 20CrdJ | 880 | 800 | Water,oil | 200 | Water, air | 835 | 540 | 10 | 179 |
785 | 490 | 10 | 179 | |||||||
8 | 30Cr | 860 | oil | 500 | Water, oil | 885 | 685 | 11 | 187 | |
9 | 35Cr | 860 | oil | 500 | Water, oil | 930 | 735 | 11 | 207 | |
10 | 40Cr | 850 | oil | 520 | Water, oil | 980 | 785 | 9 | 207 | |
11 | 45Cr | 840 | oil | 520 | Water, oil | 1 030 | 835 | 9 | 217 | |
12 | 50Cr | 830 | oil | 520 | Water, oil | 1 080 | 930 | 9 | 229 | |
13 | 38CrSi | 900 | oil | 600 | Water, oil | 980 | 835 | 12 | 255 | |
14 | 20CrModJ | 880 | Water,oil | 500 | Water, oil | 885 | 685 | 11 | 197 | |
845 | 635 | 12 | 197 | |||||||
15 | 35CrMo | 850 | oil | 550 | Water, oil | 980 | 835 | 12 | 229 | |
16 | 42CrMo | 850 | oil | 560 | Water, oil | 1 080 | 930 | 12 | 217 | |
17 | 38CrMoAld | 940 | Water, oil | 640 | Water, oil | 980 | 835 | 12 | 229 | |
930 | 785 | 14 | 229 | |||||||
18 | 50CrVA | 860 | oil | 500 | Water, oil | 1 275 | 1 130 | 10 | 255 | |
19 | 2OCrMn | 850 | oil | 200 | Water、air | 930 | 735 | 10 | 187 | |
20 | 20CrMnSif | 880 | oil | 480 | Water, oil | 785 | 635 | 12 | 207 | |
21 | 3OCrMnSif | 880 | oil | 520 | Water, oil | 1 080 | 885 | 8 | 229 | |
980 | 835 | 10 | 229 | |||||||
22 | 35CrMnSiA£ | 880 | oil | 230 | Water、air | 1 620 | 9 | 229 | ||
23 | 20CrMnTie-f | 880 | 870 | oil | 200 | Water、air | 1 080 | 835 | 10 | 217 |
24 | 30CrMnTie*f | 880 | 850 | oil | 200 | Water、air | 1 470 | 9 | 229 | |
25 | 12CrNi2 | 860 | 780 | Water,oil | 200 | Water、air | 785 | 590 | 12 | 207 |
26 | 12CrNi3 | 860 | 780 | oil | 200 | Water、air | 930 | 685 | 11 | 217 |
27 | 12Cr2Ni4 | 860 | 780 | oil | 200 | Water、air | 1 080 | 835 | 10 | 269 |
28 | 40CrNiMoA | 850 | —— | oil | 600 | Water、air | 980 | 835 | 12 | 269 |
29 | 45CrNiMoVA | 860 | — | oil | 460 | oil | 1 470 | 1 325 | 7 | 269 |
a. Allowable adjustment range of heat treatment temperature listed in the table: quenching ± 15 ℃, low temperature tempering ± 20 ℃, high temperature tempering soil 50 ℃.b. In the tensile test, transverse or longitudinal samples can be taken. In case of disagreement, the longitudinal sample is used as the basis for arbitration.c. Boron-containing steel can be normalized before quenching, and the normalizing temperature should not be higher than its quenching temperature.d. Delivery according to a set of data specified by the demander. When the demander has not specified, delivery can be made according to any of the data.e. The first quenching of titanium steel with Ming Meng can be replaced by normalizing.
f. Isothermal quenching at 280 C ~320 C. g. In the tensile test, if Rel cannot be measured, Rp0.2 can be measured instead of Rel. |
Test Requirement
Chemical composition:
Stretch,Hardness,Shock,Squash,Bending,Ultrasonic testing,Eddy current,detection,Leak detection,Galvanized