ASTM A312 TP309HCb Austenitic Stainless Steel Pipes
ASTM A312 TP309HCb is a modified, stabilized high-temperature austenitic stainless steel pipe designed for enhanced strength, creep resistance, and oxidation performance. The addition of Columbium (Cb/Nb) provides superior carbide stabilization, making TP309HCb ideal for severe high-temperature environments, including furnaces, reformer tubes, boilers, and petrochemical processing units.
Its composition is similar to TP309H but upgraded with niobium stabilization, offering extended service life in thermal cycling and carburizing conditions.
Key Features
- Columbium (Nb/Cb) stabilized for enhanced high-temperature creep strength
- Excellent oxidation & scaling resistance up to 1100°C
- High stability against sensitization & carbide precipitation
- Superior strength in cyclic thermal loads
- Great weldability and fabricability
- Ideal for severe high-temperature & carburizing atmospheres
- Extended service life in heat-treating and petrochemical applications
Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ASTM / ASME | TP309HCb |
| UNS | Based on S30909 (H-grade) + Cb Addition |
| EN/DIN | Similar to 1.4828 (modified) |
| JIS | SUS309H (modified with Nb) |
Available Sizes
-
Outside Diameter (OD): 6 mm – 610 mm
-
Wall Thickness: 1 mm – 60 mm
-
Pipe Types: Seamless, ERW, EFW, Fabricated
-
Length: Up to 12 meters
ASTM A312 TP309HCb Chemical Composition
| Element | Content (%) |
|---|---|
| C | 0.04 – 0.10 |
| Mn | ≤ 2.00 |
| Si | ≤ 1.00 |
| P | ≤ 0.045 |
| S | ≤ 0.030 |
| Cr | 22.0 – 24.0 |
| Ni | 12.0 – 15.0 |
| Cb/Nb | 0.20 – 1.0 |
| N | ≤ 0.10 |
| Fe | Balance |
ASTM A312 TP309HCb Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | ≥ 620 MPa |
| Yield Strength (0.2% Proof) | ≥ 290 MPa |
| Elongation | ≥ 40% |
| Hardness | ≤ 192 HB |
ASTM A312 TP309HCb Physical Properties
| Property | Value |
|---|---|
| Density | 7.90 g/cm³ |
| Melting Range | 1398 – 1454°C |
| Thermal Conductivity (100°C) | 14.2 W/m·K |
| Electrical Resistivity | 0.78 µΩ·m |
| Specific Heat | 500 J/kg·K |
| Coefficient of Thermal Expansion | 15.3 µm/m°C (20–100°C) |
Types of TP309HCb Pipes
- Seamless Pipes
- Welded Pipes
- ERW Pipes
- EFW Pipes
- Hot Finished Pipes
- Cold Drawn Pipes
- Polished Pipes (180 / 240 / 320 / 600 Grit)
- Fabricated Pipes
Applications
- Furnace Components
- Heat Exchanger Tubes
- Reformer Tubes
- Petrochemical Processing
- Boiler & Superheater Systems
- High-Temperature Reactors
- Carburizing & Annealing Furnace Parts
- Chemical Processing Plants
- Kilns & Burner Assemblies
Reviews
There are no reviews yet.