Chemical Composition Requirements，%，
C: ≤0.30
Mn: 0.29-1.06
P: ≤0.025
S: ≤0.025
Si: ≥0.10
Ni: ≤0.40
Cr: ≤0.30
Cu: ≤0.40
V: ≤0.08
Nb: ≤0.02
Mo: ≤0.12
*Manganese content may be increased by 0.05% for each 0.01% decrease in carbon content up to 1.35%.
**Niobium content, based on agreement, may be increased up to 0.05% for melt analysis and 0.06% for finished product analysis.
Heat treatment requirements:
1. Normalize above 815°C.
2. Normalize above 815°C, then temper.
3. Hot formed between 845 and 945°C, then cooled in furnace above 845°C (for seamless tubes only).
4. Machined and then tempered as per above Point 3.
5. Hardened and then tempered above 815°C.
Mechanical performance requirements:
Yield strength: ≥240Mpa
Tensile strength: ≥415Mpa
Elongation：
|
Sample |
A333 GR.6 |
|
|
Vertical |
Transverse |
|
|
Minimum value of a standard circular specimen or a small scale specimen with a marking distance of 4D |
22 |
12 |
|
Rectangular specimens with wall thicknesses of 5/16 in. (7.94 mm) and greater,and all small-size specimens tested in full cross-section at 2 in. (50 mm) markings |
30 |
16.5 |
|
Rectangular specimens up to 5/16 in. (7.94 mm) wall thickness at 2 in. (50 mm) marking distance (specimen width 1/2 in., 12.7 mm) |
A |
A |
A Allow a 1.5% reduction in longitudinal elongation and a 1.0% reduction in transverse elongation for each 1/32 in. (0.79 mm) of wall thickness up to 5/16 in. (7.94 mm) from the elongation values listed above.
Impact Test
Test Temperature: -45°C
When small Charpy impact specimens are used and the specimen notch width is less than 80% of the actual thickness of the material, a lower impact test temperature should be used as calculated in Table 6 of the ASTM A333 specification.
|
Sample, mm |
Minimum average of three samples |
Minimum value of one of the three samples |
|
10 × 10 |
18 |
14 |
|
10 × 7.5 |
14 |
11 |
|
10 × 6.67 |
12 |
9 |
|
10 × 5 |
9 |
7 |
|
10 × 3.33 |
7 |
4 |
|
10 × 2.5 |
5 |
4 |
Steel pipes should be hydrostatically or non-destructively tested (eddy current or ultrasonic) on a branch-by-branch basis.
Tolerance of the outer diameter of the steel pipe:
|
Outside Diameter, mm |
positive tolerance,mm |
negative tolerance,mm |
|
10.3-48.3 |
0.4 |
0.4 |
|
48.3＜D≤114.3 |
0.8 |
0.8 |
|
114.3＜D≤219.10 |
1.6 |
0.8 |
|
219.1＜D≤457.2 |
2.4 |
0.8 |
|
457.2＜D≤660 |
3.2 |
0.8 |
|
660＜D≤864 |
4.0 |
0.8 |
|
864＜D≤1219 |
4.8 |
0.8 |
Wall thickness tolerance of steel pipe:
Any point shall not be less than 12.5% of the nominal wall thickness. If the minimum wall thickness is ordered, no point shall be less than the required wall thickness.
Post time: Feb-22-2024