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| Brand Name: | TORICH |
| Model Number: | GB/T20409 |
| MOQ: | 2 Ton |
| Price: | 1000-1500 USD/Ton |
| Payment Terms: | L/C, D/A, D/P, T/T, Western Union, MoneyGram |
| Supply Ability: | 50000Ton per year |
Product Name:TORICH GB/T20409 20G 20MnG 25MnG SA210 SA213 Multi-rifled High-pressure Boiler Seamless Steel Tubes
Standard: GB/T20409
OD: 3-420mm
WT: 0.5-50mm
Length: 8-12m or according to customers' actual application and production.
Application:High-pressure Boiler
Steel Grade:20G 20MnG 25MnG SA210 SA213
Technology:Hot rolled,cold rolled,cold drawn
Characteristic:
Good concentricity
Good surface quality
Good OD and ID tolerance
High Precision
Stable quality
Smooth Roughness
TORICH QUALITY ASSURANCE
Table6 Longitudinal mechanical properties of internal screw tubes at room temperature
| Number | Grade | tensile strength
MPa(N/ | Lower yield strength /MPa((N/) | Elongation A/% | Impact energy
|
| Not less than | |||||
| 1 | 20G | 410~550 | 245 | 24 | 35 |
| 2 | 20MnG | ≥415 | 240 | 22 | 35 |
| 3 | 25MnG | ≥485 | 275 | 20 | 35 |
| 4 | 12CrMoG | 410~560 | 205 | 21 | 35 |
| 5 | 15CrMoG | 440~640 | 235 | 21 | 35 |
Table4 The grade and chemical composition of steel
| Number | Brand | chemical composition(mass fraction)/ % | ||||||
| C | Mn | Si | Cr | Mo | S | P | ||
| 1 | 20G | 0.17~0.23 | 0.35~0.65 | 0.17~0.37 | -- | -- | ≤0.020 | ≤0.025 |
| 2 | 20MnG | 0.17~0.23 | 0.70~1.00 | 0.17~0.37 | -- | -- | ≤0.020 | ≤0.025 |
| 3 | 25MnG | 0.22~0.29 | 0.7~1.00 | 0.17~0.37 | -- | -- | ≤0.020 | ≤0.025 |
| 4 | 12CrMoG | 0.08~0.15 | 0.40~0.70 | 0.17~0.37 | 0.40~0.70 | 0.40~0.55 | ≤0.020 | ≤0.025 |
| 5 | 15CrMoG | 0.12~0.18 | 0.40~0.70 | 0.17~0.37 | 0.80~1.10 | 0.40~0.55 | ≤0.020 | ≤0.025 |
| Note1:Residual element content of 20G,20MnG,25MnG should satisfy: Cu≤0.20%,Cr≤0.25%,Ni≤0.25%,V≤0.08%,Mo≤0.15%；The remaining elements of other brands should satisfy: Cu≤0.20%,Ni≤0.30%. Note2:The acid soluble aluminum in 20G steel should not be more than 0.010%. Note3:The nitrogen content of the steel produced by the oxygen converter plus the refining of the furnace should not be more than 0.008%. | ||||||||
The size of the internal screw tubes and the allowable deviation of the thread parameters
| Code | Project | “A” teeth types allowable deviation | “B” teeth types allowable deviation |
| A | O.D≤38.1mm 38.1mm＜O.D＜50.8mm 50.8mm≤O.D≤63.5mm O.D≥63.5mm | ±0.15mm ±0.20mm ±0.25mm ±0.30mm | -- |
| B | O.D≤38.1mm 38.1mm＜O.D＜50.8mm 50.8mm≤O.D≤63.5mm O.D≥63.5mm | -- | ±0.15mm ±0.20mm ±0.25mm ±0.30mm |
| C | I.D of the root of the screw Thread: O.D-(1.11×Minimum W.T×2) O.D≤38.1mm 38.1mm＜O.D＜50.8mm 50.8mm≤O.D≤63.5mm O.D≥63.5mm | ±0.15mm ±0.20mm ±0.25mm ±0.30mm | ±0.15mm ±0.20mm ±0.25mm ±0.30mm |
| E | Minimum I.D | Negative deviation to zero | Negative deviation to zero |
| F | Minimum W.T | +22% 0 | +22% 0 |
| G | Thread tips | -- | -- |
| I | Thread top width | -- | -- |
| Height of thread: O.D≤38.1mm 38.1mm＜O.D＜50.8mm 50.8mm≤O.D≤63.5mm O.D≥63.5mm | ±0.3mm | ±0.18mm ±0.20mm ±0.23mm ±0.28mm |
| K | Side Angle of thread. | ±15° | ±15° |
| O | radius of rounded corner at the root of thread | -- | -- |
| M | Thread pitch | ±3.2mm | ±3.2mm |
| N | Thread lead | ±3.2mm×thread tips | ±3.2mm×thread tips |
| Helix angle | Rating | Rating |
| T | Thread top width (axial) | ±1.3mm | ±1.3mm |
| U | Thread top (axial) groove width | -- | -- |
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