GB/T 5310 Seamless Steel Tubes
12Cr2MoWVTiB High Pressure Boiler Tubes
GB/T 5310 12Cr2MoWVTiB High Pressure Boiler Tubes
Short Description:
12Cr2MoWVTiB Seamless Steel Tubes can be used for boiler superheat tube panel and reheat The manufacture of boiler tube and main steam tube, in which superheater tube and reheater tube are called serpentine tube.
12Cr2MoWVTiB steel is a kind of multi-element microalloyed low-alloy bainite heat-resistant steel developed by ourselves from the end of 1960s to the middle of 1970s in China. Due to the proper coordination of various alloy elements, the steel has high heat strength, and its heat strength performance and service temperature are higher than those of the same kind of steel abroad. Therefore, 12Cr2MoWVTiB can be used for boiler superheat tube panel and reheat The manufacture of boiler tube and main steam tube, in which superheater tube and reheater tube are called serpentine tube.
Temperature application range: wall temperature ≤ 600 ℃ (620 ℃ can be used when considering oxidation loss in strength calculation)
GB/T 5310 12Cr1MoVG High Pressure Boiler Tubes Quick Details
Manufacture:Seamless process
Specification: 38mm * 5mm, 42mm * 3.5mm, 42mm * 5mm
Length: 6M or specified length as required.
Additional Info
Surface: Tubes will be varnished (Outside only) to prevent rust.
Marking: Standard + Steel Grade + Size + Heat No + Lot No
Package: Bundles (hexagonal), Wooden Boxes, Crates (steel/wooden) or as required
Chemical composition of GB/T 5310 12Cr2MoWVTiB
| Grade | C | Si | Mn | Cr | Mo | V |
| 12Cr2MoWVTiB | 0.08-0.15 | 0.45-0.75 | 0.45-0.65 | 1.60-2.10 | 0.50-0.65 | 0.28-0.42 |
| Ti | B | W | P | S | ||
| 0.08-0.18 | 0.002-0.008 | 0.30-0.55 | ≤0.025 | ≤0.015 |
Mechanical properties of GB/T 5310 12Cr2MoWVTiB
| Grade | Tensile strength(MPa) | Yield strength(MPa) | Elongation | Hardness |
| 12Cr2MoWVTiB | 540-735 | ≥345 | ≥18% | — |
Tolerance of outer diameter and wall thickness
| Type of steel pipe | Outer diameter(mm) | Tolerance | |||
| ordinary | advanced | ||||
| Hot rolled tube | OD | ≤50 | ±0.40 | ±0.30 | |
| ＞50～≤325 | WT≤35 | ±0.75% | ±0.5% | ||
| WT＞35 | ±1% | ±0.75% | |||
| ＞325 | ±1% | ±0.75% | |||
| WT | ≤4.0 | ±0.4 | ±0.3 | ||
| ＞4.0～≤20 | ±10% | ±7.5% | |||
| ＞20 | OD＜219 | ±10% | ±7.5% | ||
| OD≥219 | +12.5% -10% | ±10% | |||
| Cold drawn tube | OD | ≤25.4 | ±0.15 | — |
| ＞25.4～≤40 | ±0.20 | — | ||
| ＞40～≤50 | ±0.25 | — | ||
| ＞50～≤60 | ±0.30 | — | ||
| ＞60 | ±0.5% | — | ||
| WT | ≤2.8 | ±0.2 | — | |
| ＞2.8 | ±7.5% | — |
Testings of GB/T 5310 12Cr2MoWVTiB
(1)Hydraulic test
(2)Flattening test
(3)Bending test
(4)Flaring test
(5)Low-power test
(6) Non-metallic inclusions
(7)grain size
(8)Microstructure
(9)Decarburization layer
(10)Non-destructive testing
Process performance of 12Cr2MoWVTiB
(1) Forging:
The start temperature of rolling (forging) of 12Cr2MoWVTiB steel is 1150 ~ 1200ec, and the end temperature is 850 ° C. after rolling (forging), the steel is cooled by stacking.
(2) Cold bending
12Cr2MoWVTiB steel is mainly used for small-diameter steel tubes. Generally, the steel pipes need to be cold bent and do not need heat treatment after cold bending.
(3) Heat treatment process (according to GB5310-2008 standard)
Normalizing and tempering: normalizing temperature: 1020ec ~ 1060 ° C; holding for 30min; tempering temperature: 760ec ~ 790ec, holding for 3h; normalizing structure is granular bainite, normalizing + high temperature tempering structure is tempered bainite.
(4) Selection of welding materials:
The weldability of 12Cr2MoWVTiB steel is good. It can be used for manual arc welding, gas welding, friction welding, TIG welding and plasma welding. R347 welding rod is used for manual arc welding, h08cr2movnb welding wire is used for gas welding, butt joint with 12Cr1MoV steel, h08crmov or h08cr2movnb welding wire is used. Neutral partial oxidation flame is suitable for gas welding. After welding, it shall be normalized at 1000-1030 ℃ and tempered at 760-780 ° C. before manual arc welding with thickness greater than 6mm, it shall be preheated to 250-300ec, and tempered at 760-780 ° C after welding. After butt welding, it should be heated to 780ec, kept warm for 40 minutes, and then cooled to below 400ec