Seamless steel tubes for normal structure
Standard: GB/8162-2008 | Alloy Or Not: Alloy or carbon |
Grade Group: 10,20,35, 45,Q345,Q460,Q490,Q620,42CrMo,35CrMo,Etc | Application: Structural pipe, mechanical pipe |
Thickness: 1 - 100 mm | Surface Treatment: As customer's requirement |
Outer Diameter(Round): 10 - 1000 mm | Technique: Hot Rolled or Cold Rolled |
Length: Fixed length or random length | Heat treatment: Annealing/Normalizing/Stress Relieving |
Section Shape: Round | Special Pipe: Thick Wall Pipe |
Place of Origin: China | Usage: Construction, mechanical |
Certification: ISO9001:2008 | Test: ECT/UT |
It Is Mainly Used To Make Carbon Structural Steel, Alloy Structural Steel and mechanical structures.
Grade Of Carbon Structural Steel: 10,20,35, 45,Q345,Q460,Q490,Q620,, Etc
Grade Of Alloy Structural Steel: 42CrMo,35CrMo, Etc
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 | 0.2 | 0.5 | 1.7 | 0.035 | 0.035 | 0.3 | 0.5 | 0.2 | 0.012 | 0.1 | —— | — | |||
B | 0.035 | 0.035 | ||||||||||||||
C | 0.03 | 0.03 | 0.07 | 0.15 | 0.2 | 0.015 | ||||||||||
D | 0.18 | 0.03 | 0.025 | |||||||||||||
E | 0.025 | 0.02 | ||||||||||||||
Q390 | A | 0.2 | 0.5 | 1.7 | 0.035 | 0.035 | 0.07 | 0.2 | 0.2 | 0.3 | 0.5 | 0.2 | 0.015 | 0.1 | — | — |
B | 0.035 | 0.035 | ||||||||||||||
C | 0.03 | 0.03 | 0,015 | |||||||||||||
D | 0.03 | 0.025 | ||||||||||||||
E | 0.025 | 0.02 | ||||||||||||||
Q42O | A | 0.2 | 0.5 | 1.7 | 0.035 | 0.035 | 0.07 | 0.2 | 0.2 | 0.3 | 0.8 | 0.2 | 0.015 | 0.2 | —— | —— |
B | 0.035 | 0.035 | ||||||||||||||
C | 0.03 | 0.03 | 0.015 | |||||||||||||
D | 0.03 | 0.025 | ||||||||||||||
E | 0.025 | 0.02 | ||||||||||||||
Q46O | C | 0.2 | 0.6 | 1.8 | 0.03 | 0.03 | 0.11 | 0.2 | 0.2 | 0.3 | 0.8 | 0.2 | 0.015 | 0.2 | 0.005 | 0.015 |
D | 0.03 | 0.025 | ||||||||||||||
E | 0.025 | 0.02 | ||||||||||||||
Q500 | C | 0J8 | 0.6 | 1.8 | 0.025 | 0.02 | 0.11 | 0.2 | 0.2 | 0.6 | 0.8 | 0.2 | 0.015 | 0.2 | 0.005 | 0.015 |
D | 0.025 | 0.015 | ||||||||||||||
E | 0.02 | 0.01 | ||||||||||||||
Q550 | C | 0.18 | 0.6 | 2 | 0.025 | 0,020 | 0.11 | 0.2 | 0.2 | 0.8 | 0.8 | 0.2 | 0.015 | 0.3 | 0.005 | 0.015 |
D | 0.025 | 0,015 | ||||||||||||||
E | 0.02 | 0.01 | ||||||||||||||
Q62O | C | 0.18 | 0.6 | 2 | 0.025 | 0.02 | 0.11 | 0.2 | 0.2 | 1 | 0.8 | 0.2 | 0.015 | 0.3 | 0.005 | 0.015 |
D | 0.025 | 0.015 | ||||||||||||||
E | 0.02 | 0.01 | ||||||||||||||
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 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. |
Allowable deviation of outer diameter of steel pipe
Type of steel pipe |
Allowable Tolerance |
Hot rolled steel pipe |
± 1% D or ± 0.5, whichever is greater |
Cold drawn steel pipe |
Soil 0,75% D or soil 0.3, whichever is greater |
Allowable deviation of wall thickness of hot rolled (extended) steel pipe
Type of steel pipe |
D |
S/D |
Allowable Tolerance |
Hot rolled steel pipe |
<102 |
— |
± 12.5% S or ± 0.4, whichever is greater |
>102 |
<0.05 |
± 15% S or ± 0,4, whichever is greater |
|
>0.05 〜0.10 |
± 12.5% S or ± 0.4, whichever is greater |
||
>0.10 |
+ 12.5%S -10%S |
||
Heat expanded steel pipe |
一 |
土 15%S |
Allowable deviation of wall thickness of cold drawn (rolled) steel pipe
|
S |
Allowable Tolerance |
Cold drawing (rolling) |
V |
+ 15% S Or 0.15, whichever is greater —10% S |
>3 — 10 |
+ 12.5%S —10%S |
|
>10 |
土 10%S |
Chemical composition,Stretch,Hardness,Shock,Squash,Bending,Ultrasonic testing,Eddy current,detection,Leak detection,Galvanized
Seamless Steel Tubes For Structural Purposes, Seamless Steel Tubes For Mechanical Structures In GB/8162-2008 Standard. In the seamless steel tube series, there is a kind of material called Q345B seamless steel tube is a low alloy series. In the low alloy material, this material is the most common. Q345 seamless steel tube is a kind of steel tube material. Q is the yield of this material, and 345 is the yield of this material, which is around 345. And the yield value will decrease with the increase of material thickness. Q345A level, is not impact; Q345B, is 20 degrees normal temperature impact; Q345C class, is 0 degree impact; Q345D, is -20 degree impact; Class Q345E, minus 40 degrees. The impact value is also different at different impact temperatures. Q345A, Q345B, Q345C, Q345D, Q345E. This is the grade of distinction, which represents, mainly impact temperature is different.
Execution standard
1. Seamless pipe for structure (GB/T8162-2018) is a seamless steel pipe for general structure and mechanical structure. 2. Seamless steel pipe for fluid transportation (GB/T8163-2018) is used for conveying water, oil, gas and other fluids in general seamless steel pipe. 3. Seamless steel tubes for low and medium pressure boilers (GB3087-2018) are high quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel tubes, which are used for manufacturing superheated steam pipes, boiling water pipes of various structures of low and medium pressure boilers and superheated steam pipes and arch brick pipes for locomotive boilers. 4. Seamless steel tube for high pressure boiler (GB5310-2018) is used for manufacturing high pressure and above pressure water tube boiler heating surface with high quality carbon steel, alloy steel and stainless heat resistant steel seamless steel tube.
Q345B Seamless steel tube specification sheet |
|||
specification |
specification |
specification |
specification |
14*3 |
38*5.5 |
89*5 |
133*18 |
14*3.5 |
42*3 |
89*5.5 |
159*6 |
14*4 |
42*3.5 |
89*6 |
159*6.5 |
16*3 |
42*4 |
89*7 |
159*7 |
18*2 |
42*5 |
89*7.5 |
159*8 |
18*3 |
42*6 |
89*8 |
159*9.5 |
18*4 |
42*8 |
89*9 |
159*10 |
18*5 |
45*3 |
89*10 |
159*12 |
19*2 |
45*4 |
89*11 |
159*14 |
21*4 |
45*5 |
89*12 |
159*16 |
22*2.5 |
45*6 |
108*4.5 |
159*18 |
22*3 |
45*7 |
108*5 |
159*20 |
22*4 |
48*4 |
108*6 |
159*28 |
22*5 |
48*4.5 |
108*7 |
168*6 |
25*2.5 |
48*5 |
108*8 |
168*7 |
25*3 |
48*6 |
108*9 |
168*8 |
25*4 |
48*7 |
108*10 |
168*9.5 |
25*5 |
48.3*12.5 |
108*12 |
168*10 |
25*5.5 |
51*3 |
108*14 |
168*11 |
27*3.5 |
51*3.5 |
108*15 |
168*12 |
27*4 |
51*4 |
108*16 |
168*14 |
27*5 |
51*5 |
108*20 |
168*15 |
27*5.5 |
51*6 |
114*5 |
168*16 |
28*2.5 |
57*4 |
114*6 |
168*18 |
28*3 |
57*5 |
114*7 |
168*20 |
28*3.5 |
57*5.5 |
114*8 |
168*22 |
28*4 |
57*6 |
114*8.5 |
168*25 |
30*2.5 |
60*4 |
114*9 |
168*28 |
32*2.5 |
60*4 |
114*10 |
180*10 |
32*3 |
60*5 |
114*11 |
194*10 |
32*3.5 |
60*6 |
114*12 |
194*12 |
32*4 |
60*7 |
114*13 |
194*14 |
32*4.5 |
60*8 |
114*14 |
194*16 |
32*5 |
60*9 |
114*16 |
194*18 |
34*3 |
60*10 |
114*18 |
194*20 |
34*4 |
76*4.5 |
133*5 |
194*26 |
34*4.5 |
76*5 |
133*6 |
219*6.5 |
34*5 |
76*6 |
133*7 |
219*7 |
34*6.5 |
76*7 |
133*8 |
219*8 |
38*3 |
76*8 |
133*10 |
219*9 |
38*3.5 |
76*9 |
133*12 |
219*10 |
38*4 |
76*10 |
133*13 |
219*12 |
38*4.5 |
89*4 |
133*14 |
219*13 |
38*5 |
89*4.5 |
133*16 |
219*14 |
219*16 |
273*36 |
356*28 |
426*12 |
219*18 |
273*40 |
356*36 |
426*13 |
219*20 |
273*42 |
377*9 |
426*14 |
219*22 |
273*45 |
377*10 |
426*17 |
219*24 |
298.5*36 |
377*12 |
426*20 |
219*25 |
325*8 |
377*14 |
426*22 |
219*26 |
325*9 |
377*15 |
426*30 |
219*28 |
325*10 |
377*16 |
426*36 |
219*30 |
325*11 |
377*18 |
426*40 |
219*32 |
325*12 |
377*20 |
426*50 |
219*35 |
325*13 |
377*22 |
457*9.5 |
219*38 |
325*14 |
377*25 |
457*14 |
273*7 |
325*15 |
377*32 |
457*16 |
273*8 |
325*16 |
377*36 |
457*19 |
273*9 |
325*17 |
377*40 |
457*24 |
273*9.5 |
325*18 |
377*45 |
457*65 |
273*10 |
325*20 |
377*50 |
508*13 |
273*11 |
325*22 |
406*9.5 |
508*16 |
273*12 |
325*23 |
406*11 |
508*20 |
273*13 |
325*25 |
406*13 |
508*22 |
273*15 |
325*28 |
406*17 |
558.8*14 |
273*16 |
325*30 |
406*22 |
530*13 |
273*18 |
325*32 |
406*32 |
530*20 |
273*20 |
325*36 |
406*36 |
570*12.5 |
273*22 |
325*40 |
406*40 |
610*13 |
273*25 |
325*45 |
406*55 |
610*18 |
273*28 |
356*9.5 |
406.4*50 |
610*78 |
273*30 |
356*12 |
406.4*55 |
624*14.2 |
273*32 |
356*15 |
406*60 |
824*16.5 |
273*35 |
356*19 |
406*65 |
824*20 |
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 |
0.2 |
0.5 |
1.7 |
0.035 |
0.035 |
0.3 |
0.5 |
0.2 |
0.012 |
0.1 |
—— |
— |
|||
B |
0.035 |
0.035 |
||||||||||||||
C |
0.03 |
0.03 |
0.07 |
0.15 |
0.2 |
0.015 |
||||||||||
D |
0.18 |
0.03 |
0.025 |
|||||||||||||
E |
0.025 |
0.02 |
||||||||||||||
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 |
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 |
|||||||
Q345 |
A |
470—630 |
345 |
325 |
295 |
20 |
— |
一 |
B |
4~20 |
34 |
||||||
C |
21 |
0 |
||||||
D |
-20 |
|||||||
E |
-40 |
27 |
Test Requirement
Chemical Composition: Stretch,Hardness,Shock,Squash,Bending,Ultrasonic Testing,Eddy Current,Detection,Leak Detection,Galvanized