ASTM A815 CRS41008
ASTM A815 CRS41500 Martensitic Stainless Steel Pipe Fittings
ASTM A815 CRS41500 Pipe Fittings are manufactured from martensitic stainless steel grade 41500 (UNS S41500), known for its exceptional strength, toughness, and corrosion resistance. This grade is a modification of the 410 family, enriched with nickel and molybdenum, offering superior resistance to pitting, scaling, and oxidation.
Produced in accordance with ASTM A815 / ASME SA815, these fittings are designed for high-pressure and high-temperature service in industries such as power generation, oil & gas, chemical processing, and marine systems. The “CRS” designation highlights the corrosion-resistant stainless nature of the alloy, optimized for both mechanical performance and durability in harsh environments.
Key Features
Excellent corrosion and pitting resistance due to Mo and Ni addition.
High tensile and yield strength suitable for heavy-duty pressure applications.
Good oxidation and scaling resistance up to 650°C.
Magnetic and machinable in annealed condition.
Improved weldability and formability compared to 410 and 420 grades.
Suitable for both moderate and elevated temperature service.
Specification
| Standard | ASTM A815 / ASME SA815 |
|---|---|
| Grade | CRS41500 |
| Material Type | Martensitic Stainless Steel |
| UNS Number | S41500 |
| W.Nr. | 1.4313 |
| Manufacturing Process | Seamless / Welded / Fabricated |
| Size Range | ½” NB to 48” NB |
| Wall Thickness | SCH 10S to SCH 160 / XXS |
| Form | Elbows, Tees, Reducers, Caps, Stub Ends, Crosses |
| End Connections | Beveled, Plain, or Custom Ends |
| Testing | NDT, PMI, Hydrostatic & Visual Inspections |
Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| ASTM / ASME | WPS41500 / CRS41500 |
| UNS | S41500 |
| EN | X4CrNiMo16-5-1 |
| W.Nr | 1.4313 |
| JIS | SUS630 (Approx.) |
| BS | 431S29 |
Available Sizes
Seamless Fittings: ½” NB – 24” NB
Welded Fittings: ½” NB – 48” NB
Wall Thickness: SCH 10S, 40S, 80S, 160, XXS
Custom Dimensions: Available upon request
Chemical Composition
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.05 |
| Manganese (Mn) | ≤ 1.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.040 |
| Sulfur (S) | ≤ 0.030 |
| Chromium (Cr) | 14.0 – 16.0 |
| Nickel (Ni) | 4.0 – 6.0 |
| Molybdenum (Mo) | 0.4 – 1.0 |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 760 – 930 MPa |
| Yield Strength (0.2% Proof) | 550 MPa (min) |
| Elongation | 16% (min) |
| Hardness (Brinell) | ≤ 280 HB |
| Impact Strength | ≥ 35 J (at room temperature) |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.74 g/cm³ |
| Melting Point | 1440°C |
| Modulus of Elasticity | 200 GPa |
| Thermal Conductivity | 24.9 W/m·K (at 100°C) |
| Specific Heat | 460 J/kg·K |
| Magnetic Properties | Fully Magnetic |
Types of ASTM A815 CRS41500 Fittings
ASTM A815 CRS41500 Elbow
ASTM A815 CRS41500 Tee
ASTM A815 CRS41500 Reducers
ASTM A815 CRS41500 Caps
ASTM A815 CRS41500 Cross Fittings
ASTM A815 CRS41500 Nipples
ASTM A815 CRS41500 Couplings
ASTM A815 CRS41500 Stub Ends
Corrosion Resistance
The CRS41500 grade offers superior resistance to:
Mild acids, freshwater, and atmospheric corrosion.
Oxidizing environments and steam exposure.
Pitting and crevice corrosion in chloride environments.
This makes it ideal for marine, refinery, and desalination plant applications. The molybdenum and nickel content significantly enhance its performance over standard 410 grades.
Heat Resistance
Retains mechanical integrity and scaling resistance up to 650°C (1200°F).
Withstands cyclic heating and cooling without loss of strength.
Avoid prolonged exposure between 400–600°C to prevent embrittlement.
Heat Treatment
Solution Annealing: 1000–1050°C, air or oil quenched.
Tempering: 400–600°C to achieve desired balance of hardness and ductility.
Heat treatment restores corrosion resistance and removes welding stresses.
Welding
Readily weldable using TIG (GTAW), MIG (GMAW), SMAW, and SAW processes.
Preheat: 150–250°C | Post-weld tempering: 650–750°C recommended.
Filler Metals: E410NiMo or E309 (for dissimilar joints).
Post-weld heat treatment enhances toughness and reduces stress cracking risk.
Fabrication
Good machinability and formability in the annealed state.
Can be cold-formed with minimal spring-back.
Stress-relief annealing recommended after heavy forming.
Surface finishing and polishing achievable for high-specification process systems.
Applications
Oil & Gas Processing Plants
Power Generation Systems
Heat Exchangers & Condensers
Steam Turbines & Pressure Vessels
Marine & Offshore Components
Pump Shafts, Valves & Fasteners
Petrochemical & Pulp Industry Equipment