ASTM A815 CR27
ASTM A815 CR27 Stainless Steel Pipe Fittings
ASTM A815 CR27 refers to corrosion-resistant stainless steel pipe fittings produced under the ASTM A815/A815M standard, which covers wrought ferritic, ferritic/austenitic, and martensitic stainless steel fittings.
The CR27 grade falls under the CR (Corrosion-Resistant) class, specifically intended for low-pressure and corrosive service applications. These fittings are manufactured in accordance with MSS-SP-43 requirements.
CR27 corresponds to UNS S44627, a high-chromium ferritic stainless steel grade. The designation “27” reflects its chromium content—approximately 27%, giving the material outstanding resistance to scaling, corrosion, and chloride-induced degradation.
Key Features:
Exceptional corrosion resistance especially against pitting and crevice corrosion
High tensile and yield strength for pressure resistance
Good resistance to oxidation at elevated temperatures
Suitable for welding, bending, and fabrication processes
Complies with ASTM A815 standards for ferritic stainless steel piping fittings
Technical Specification Overview
| Specification | Details |
|---|---|
| Standard | ASTM A815 / ASME SA815 |
| Grade | CR27 Duplex Stainless Steel |
| Form | Seamless, Welded, Fabricated Buttweld Fittings |
| Size Range | ½” – 48” |
| Schedule | SCH 5S – XXS |
| Pressure Class | 150# – 2500# |
| Manufacturing Standard | ASME B16.9 / B16.28 / MSS-SP43 |
Equivalent Grades
| Standard | Equivalent Grade* |
|---|---|
| UNS | S32750 / S32760 (Performance Equivalent) |
| WNR | 1.4410 / 1.4501 |
| EN | X2CrNiMoN25-7-4 / X2CrNiMoCuWN25-7-4 |
| Trade Names | Super Duplex / CR27 Duplex Family |
Chemical Composition (Typical)
| Element | Content (%) |
|---|---|
| C | ≤ 0.03 |
| Mn | ≤ 2.00 |
| Si | ≤ 1.00 |
| P | ≤ 0.035 |
| S | ≤ 0.020 |
| Cr | 26.0 – 28.0 |
| Ni | 6.0 – 8.0 |
| Mo | 3.0 – 4.0 |
| N | 0.20 – 0.30 |
| Fe | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | ≥ 750 MPa |
| Yield Strength | ≥ 550 MPa |
| Elongation | ≥ 25% |
| Hardness | ≤ 32 HRC |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.8 g/cm³ |
| Melting Range | ~1350°C |
| Thermal Conductivity | 14 W/m-K |
| Modulus of Elasticity | 200 GPa |
| Electrical Resistivity | 0.85 µΩ-m |
Types of ASTM A815 CR27 Fittings
ASTM A815 CR27 Elbow
ASTM A815 CR27 Tee
ASTM A815 CR27 Reducers
ASTM A815 CR27 Caps
ASTM A815 CR27 Cross Fittings
ASTM A815 CR27 Nipples
ASTM A815 CR27 Couplings
ASTM A815 CR27 Stub Ends
Corrosion Resistance
Exceptional resistance to chloride-induced corrosion
Excellent resistance to pitting & crevice corrosion
Resistant to sour gas & brine environments
Ideal for marine & chemical service
Heat Resistance
Stable mechanical properties up to 300–350°C
Excellent oxidation resistance in moderate high temperatures
Heat Treatment
Solution Annealing: 1040–1120°C
Rapid cooling for optimum duplex microstructure
Not hardened by heat treatment
Welding
Suitable for TIG / MIG / SMAW
Recommended filler metal: ER2594
Avoid excessive heat input to prevent phase imbalance
Post-weld cleaning recommended
Fabrication
Good machinability & formability
Requires rigid tooling due to high strength
Best worked in annealed condition
Applications
Offshore Oil & Gas Platforms
Seawater & Desalination Plants
Chemical & Petrochemical Plants
Heat Exchangers & Pressure Vessels
Power Generation & Energy Plants
Marine & Shipbuilding
Water Treatment Systems
Pulp & Paper Industry