ASTM A403 WP310S
ASTM A403 WP310S Pipe Fittings
ASTM A403 WP310S is a premium grade of austenitic stainless steel butt-weld fittings specially engineered for high-temperature and high-oxidation environments. This low-carbon variant of 310 stainless steel offers excellent thermal stability, superior oxidation resistance, and enhanced weldability, making it ideal for continuous elevated-temperature operations in industries like petrochemical, heat processing, power generation, and furnace equipment manufacturing.
With high chromium and nickel content, WP310S fittings perform exceptionally well in severe carburizing and nitrogen-rich atmospheres, ensuring long-lasting resistance to corrosion, scaling, and thermal fatigue.
Key Features
Low-carbon stainless grade for improved weldability
High nickel & chromium content for exceptional oxidation resistance
Ideal for high-temperature and cyclic heating environments
Strong resistance to sulfur-bearing atmospheres
Excellent creep strength and thermal stability
Minimal risk of sensitization after welding
Suitable for continuous service up to 1050–1100°C
Technical Specification
| Specification | Details |
|---|---|
| Standard | ASTM A403 / ASME SA403 |
| Grade | WP310S |
| UNS | S31008 |
| Material | Austenitic Stainless Steel |
| Dimension Standards | ASME B16.9 / B16.28 / MSS-SP-43 |
| Size Range | ½” to 48” |
| Thickness | SCH 10S to SCH XXS |
| Manufacturing | Seamless / Welded / ERW / Fabricated |
| Ends | Beveled / Plain End |
Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM / ASME | A403 / SA403 WP310S |
| UNS | S31008 |
| EN | 1.4845 |
| DIN | X8CrNi25-21 |
Available Sizes
Size: ½” – 48”
Schedule: SCH 10S, SCH 40S, SCH 80S, SCH 160, SCH XXS
Types: Seamless / Welded / Fabricated
Chemical Composition
| Element | % |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Chromium (Cr) | 24.0 – 26.0 |
| Nickel (Ni) | 19.0 – 22.0 |
| Molybdenum (Mo) | ≤ 0.75 |
| Silicon (Si) | ≤ 1.50 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorous (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | ≥ 515 MPa |
| Yield Strength | ≥ 205 MPa |
| Elongation | ≥ 40% |
| Hardness | ≤ 217 HB |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.9 g/cm³ |
| Melting Point | 1400 – 1454°C |
| Thermal Conductivity | 14.2 W/m-K |
| Modulus of Elasticity | ~200 GPa |
| Thermal Expansion | 15.9 µm/m°C |
Types of ASTM A403 WP310S Fittings
ASTM A403 WP310S Elbow
ASTM A403 WP310S Tee
ASTM A403 WP310S Reducers
ASTM A403 WP310S Caps
ASTM A403 WP310S Cross Fittings
ASTM A403 WP310S Nipples
ASTM A403 WP310S Couplings
ASTM A403 WP310S Stub Ends
Corrosion Resistance
Excellent resistance to oxidation and scaling up to 1100°C
Highly resistant to carburizing & nitriding atmospheres
Good corrosion resistance in sulfur-bearing environments
Suitable for high-temperature and marine exposure
Heat Resistance
Sustains temperatures up to 1050–1100°C
Excellent creep and stress-rupture strength
Performs well under cyclic heating conditions
Heat Treatment
| Process | Requirement |
|---|---|
| Solution Annealing | 1040°C – 1150°C |
| Cooling | Rapid water quench |
Welding
Weldable with TIG, MIG, SMAW, FCAW
No preheating required
Post-weld annealing generally not required
Low-carbon content reduces carbide precipitation
Fabrication
Good machinability and formability
Cold forming might need stress-relief annealing
Use carbide tools & moderate speed during machining
Applications
Heat treatment equipment & furnace parts
Petrochemical & refinery pipelines
Boiler & heat exchanger components
Power plant high-temperature lines
Thermal processing plants
Cryogenic equipment
Exhaust systems & incinerators
Chemical processing units