Grade |
Quality Class |
Chemical Property |
||||||||||||||
C |
Si |
Mn |
P |
S |
Nb |
V |
Ti |
Cr |
Ni |
Cu |
Nd |
Mo |
B |
Als" |
||
不大于 |
不小于 |
|||||||||||||||
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 |
0.18 |
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 | ||||||||||||||
Except for 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 Should meet the requirements in the table. When combined, Nb + V + Ti <0.22% °For Q345, Q390, Q420 and Q46O grades, Mo + Cr <0.30% oWhen each grade of Cr and Ni is used as the residual element, the content of Cr and Ni should not be more than 0.30%; when it needs to be added, its content should meet the requirements in the table or be determined by the supplier and the buyer through consultation.J If the supplier can guarantee 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. 'When using all aluminum, the total aluminum content AIt ^ 0.020% B |
No |
Grade |
Mechanical Property |
||||
|
|
Tensile MPa |
Yield MPa |
Extend L/T |
Impect (J) Vertical/ Horizontal |
Handness HB |
1 |
20G |
410- 550 |
≥ 245 |
24/22% |
40/27 |
— |
2 |
20MnG |
415- 560 |
≥ 240 |
22/20% |
40/27 |
— |
3 |
25MnG |
485- 640 |
≥ 275 |
20/18% |
40/27 |
— |
4 |
15MoG |
450- 600 |
≥ 270 |
22/20% |
40/27 |
— |
6 |
12CrMoG |
410- 560 |
≥ 205 |
21/19% |
40/27 |
— |
7 |
15CrMoG |
440- 640 |
≥ 295 |
21/19% |
40/27 |
— |
8 |
12Cr2MoG |
450- 600 |
≥ 280 |
22/20% |
40/27 |
— |
9 |
12Cr1MoVG |
470- 640 |
≥ 255 |
21/19% |
40/27 |
— |
10 |
12Cr2MoWVTiB |
540- 735 |
≥ 345 |
18/-% |
40/- |
— |
11 |
10Cr9Mo1VNbN |
≥ 585 |
≥ 415 |
20/16% |
40/27 |
≤ 250 |
12 |
10Cr9MoW2VNbBN |
≥ 620 |
≥ 440 |
20/16% |
40/27 |
≤ 250 |
If there is no special requirements, pipe gonna be delivery as norminal outter diameter and norminal wall thickness. As follow sheet
Classification designation |
Method of manufacture |
Size of pipe |
Tolerance |
|||
Normal grade |
High grade |
|||||
W H |
Hot Rolled(extrude) pipe |
Norminal outter Diameter (D) |
<57 |
士 0.40 |
±0,30 |
|
57 〜325 |
SW35 |
±0.75%D |
±0.5%D |
|||
S>35 |
±1%D |
±0.75%D |
||||
>325 〜6。。 |
+ 1%D or + 5.Take lesser one一2 |
|||||
>600 |
+ 1%D or + 7,Take lesser one一2 |
|||||
Norminal Wall Thickness (S) |
<4.0 |
±|・丨) |
±0.35 |
|||
>4.0-20 |
+ 12.5%S |
±10%S |
||||
>20 |
DV219 |
±10%S |
±7.5%S |
|||
心219 |
+ 12.5%S -10%S |
土 10%S |
W-H |
Thermal expansion pipe |
Norminal outter Diameter
(D) |
all |
±1%D |
±0.75%。 |
Norminal Wall Thickness
(S) |
all |
+ 20%S -10%S |
+ 15%S -io%s |
||
W-C |
Cold drawn(rolled) Ppipe |
Norminal outter Diameter
(D) |
<25.4 |
±'L1j |
— |
>25.4 〜4() |
±0.20 |
||||
>40 〜50 |
|:0.25 |
— |
|||
>50 〜60 |
±0.30 |
||||
>60 |
±0.5%D |
||||
Norminal Wall Thickness (S) |
<3.0 |
±0.3 |
±0.2 |
||
>3.0 |
S |
±7.5%S |
According to the requirements of the purchaser and stated in the contract, the steel pipe with outer diameter ≤76mm and wall thickness ≤8mm can be done flaring test . The experiment was performed at room temperature with a taper of 60 °. After the flaring, the flaring rate of the outer diameter should meet the requirements of the following table, and the test material must not show cracks or rips
Steel Type |
Outter diameter flaring rate of steel pipe/% |
||
Inner Diameter/Outter Diameter |
|||
<0.6 |
>0.6 〜0.8 |
>0.8 |
|
High-quality carbon structural steel |
10 |
12 |
17 |
Structural alloy steel |
8 |
10 |
15 |
•The inner diameter is calculated for the sample. |