ASTM A815 WPS41008
ASTM A815 WPS41008 Martensitic Stainless Steel Pipe fittings
ASTM A815 WPS41008 pipe fittings are manufactured from ferritic stainless steel grade 41008, in accordance with ASTM A815, which covers wrought ferritic, austenitic, and duplex stainless steel fittings for pressure applications.
Grade WPS41008 (UNS S41008) is a low-carbon modification of martensitic stainless steel 410, designed to provide enhanced weldability and toughness while maintaining excellent mechanical strength and moderate corrosion resistance. These fittings are commonly used in steam, oil & gas, power generation, and heat exchanger applications, where a combination of mechanical strength, oxidation resistance, and cost-effectiveness is required.
Key Features
Improved weldability due to lower carbon content.
Excellent mechanical strength and hardness.
Moderate corrosion resistance in mild atmospheres.
Good oxidation resistance up to 650°C.
Can be hardened through heat treatment.
Magnetic in all conditions.
Cost-effective and versatile for high-temperature service.
Specification
| Standard | ASTM A815 / ASME SA815 |
|---|---|
| Grade | WPS41008 |
| Material Type | Ferritic / Martensitic Stainless Steel |
| UNS Number | S41008 |
| W.Nr. | 1.4000 / 1.4006 equivalent range |
| Form | Elbows, Tees, Reducers, Caps, Stub Ends, Crosses |
| Manufacturing Process | Seamless / Welded / Fabricated |
| Size Range | ½” NB to 48” NB |
| Schedule | SCH 10S to SCH 160 / XXS |
| End Connections | Beveled, Plain, or Custom Ends |
Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM / ASME | WPS41008 |
| UNS | S41008 |
| EN | X2Cr12 |
| W.Nr | 1.4000 |
| JIS | SUS410L |
| BS | 410S21 (Modified) |
Available Sizes
Seamless Fittings: ½” to 24” NB
Welded Fittings: ½” to 48” NB
Wall Thickness: SCH 10S, 40S, 80S, 160, XXS
Custom Dimensions: Available on request
Chemical Composition
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.08 |
| Manganese (Mn) | ≤ 1.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 11.5 – 13.5 |
| Nickel (Ni) | ≤ 0.75 |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 415 – 480 MPa |
| Yield Strength (0.2% Proof) | 240 – 275 MPa |
| Elongation | 20% (min) |
| Hardness (Brinell) | ≤ 217 HB |
| Impact Toughness | Improved (vs WP410) due to lower carbon content |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.75 g/cm³ |
| Melting Point | 1450°C |
| Modulus of Elasticity | 200 GPa |
| Thermal Conductivity | 24.9 W/m·K at 100°C |
| Electrical Resistivity | 0.57 µΩ·m at 20°C |
Types of ASTM A815 WPS41008 Fittings
ASTM A815 WPS41008 Elbow
ASTM A815 WP33 Tee
ASTM A815 WP33 Reducers
ASTM A815 WP33 Caps
ASTM A815 WP33 Cross Fittings
ASTM A815 WP33 Nipples
ASTM A815 WP33 Couplings
ASTM A815 WP33 Stub Ends
Corrosion Resistance
ASTM A815 WPS41008 fittings offer moderate corrosion resistance in:
Mildly corrosive environments and freshwater.
Steam, alkaline, and petroleum atmospheres.
Lightly oxidizing environments.
The lower carbon content reduces the risk of sensitization and intergranular corrosion, improving weld performance and durability. However, it is not suitable for severe chloride or acidic environments.
Heat Resistance
Good oxidation and scaling resistance up to 650°C (1200°F).
Retains mechanical strength and stability at elevated temperatures.
Prolonged exposure between 400–600°C should be avoided to prevent embrittlement.
Heat Treatment
Annealing: 815–900°C, followed by slow furnace cooling.
Hardening: 925–1010°C, followed by air or oil quenching.
Tempering: 150–370°C depending on desired hardness.
Heat treatment enhances both toughness and wear resistance.
Welding
Improved weldability due to low carbon content.
Suitable welding methods: GTAW (TIG), GMAW (MIG), SMAW (Stick).
Preheat: 150–250°C; Post-weld tempering: 650–750°C recommended.
Filler metals such as E410, E309, or E410NiMo are suitable.
Fabrication
Good machinability and formability in the annealed condition.
Forming operations should be done with care to avoid cracking.
Post-forming annealing recommended for stress relief.
Magnetic in all conditions and readily polishable.
Applications
Steam Turbines and Heat Exchangers
Oil & Gas Processing Equipment
Petrochemical and Power Generation Plants
Pump & Valve Components
Automotive and Mechanical Parts
Structural Components and Pressure Vessels