ASTM A182 F304H
ASTM A182 F304H Flanges & Fittings
ASTM A182 F304H is a high-carbon variant of 304 stainless steel, designed to deliver superior high-temperature strength, excellent oxidation resistance, and outstanding corrosion performance. It is widely used in high-temperature steam systems, boilers, heat exchangers, petrochemicals, and power plants.
This material is manufactured through the forging process and is specifically suitable for high-pressure and high-temperature piping systems requiring excellent mechanical strength and reliability.
Key Features
High carbon content (0.04–0.10%) for improved creep & stress rupture strength
Exceptional high-temperature performance up to 800°C
Superior corrosion and oxidation resistance
Excellent weldability & formability
Good resistance to carburizing atmospheres
Suitable for pressure & heat-intensive environments
Excellent dimensional stability at elevated temperatures
Technical Specification
| Property | Description |
|---|---|
| Standard | ASTM A182 |
| Grade | F304H |
| Material | Stainless Steel (Austenitic) |
| Product Forms | Flanges, Forged Fittings, Valves, Components |
| Manufacturing | Forged / Rolled / Heat-treated |
| Pressure Class | 150#, 300#, 600#, 900#, 1500#, 2500# |
Equivalent Grades
| Standard | Grade |
|---|---|
| UNS | S30409 |
| WNR | 1.4948 |
| ASTM | A182 F304H |
| ASME | SA182 F304H |
| EN | X6CrNi18-10 (High Carbon Variant) |
| JIS | SUS304H |
Available Sizes
| Product | Size Range |
|---|---|
| Forged Fittings | ½″ to 4″ (DN15–DN100) |
| Flanges | ½″ to 48″ (DN15–DN1200) |
| Thickness | SCH 10 to XXS |
| Class | 150 to 2500 / PN 6–PN 400 |
Chemical Composition (%)
| Element | Min | Max |
|---|---|---|
| Carbon (C) | 0.04 | 0.10 |
| Chromium (Cr) | 18.0 | 20.0 |
| Nickel (Ni) | 8.0 | 11.0 |
| Manganese (Mn) | — | 2.0 |
| Silicon (Si) | — | 1.00 |
| Phosphorus (P) | — | 0.045 |
| Sulfur (S) | — | 0.030 |
| Nitrogen (N) | — | 0.10 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 515 MPa (Min) |
| Yield Strength | 205 MPa (Min) |
| Elongation | 35% (Min) |
| Hardness | 90 HRB Max |
Physical Properties
| Property | Value |
|---|---|
| Density | 8.00 g/cm³ |
| Melting Point | 1400–1450°C |
| Modulus of Elasticity | 193 GPa |
| Thermal Expansion | 17.2 µm/m°C |
| Thermal Conductivity | 14–16 W/m-K |
Type ASTM A182 F304H Flanges & Fittings
Corrosion Resistance
Excellent resistance to oxidizing environments & chloride media
Good performance in mild acidic & alkaline environments
Superior resistance to high-pressure steam & thermal cycling
Heat Resistance
Sustained operation up to 800°C
Superior creep and stress rupture strength due to high carbon content
Suitable for boiler & furnace systems
Heat Treatment
| Process | Condition |
|---|---|
| Solution Annealing | 1010–1120°C followed by rapid cooling |
| Hardening | Not hardenable by heat treatment (work-hardening only) |
Welding
Good weldability with standard techniques
Use low-carbon filler material recommended to prevent carbide precipitation
Post-weld annealing may be required for corrosion-critical service
Fabrication
Easy to cut, bend, machine, and forge
Cold working increases strength
Pre-heating not required
Applications
Refineries & Petrochemicals
Power Plants & Boilers
Heat Exchangers & Steam Pipelines
Chemical Processing Units
Oil & Gas Equipment
Furnace & Heater Components
High-Pressure Vessels & Valves
Pharmaceutical & Food Processing