ASTM A182 F12
ASTM A182 F12 Alloy Steel Pipe Flanges / Fittings
ASTM A182 F12 is a chromium-molybdenum (Cr-Mo) alloy steel grade used for forged flanges, fittings, valves, and high-temperature components. It is widely chosen for elevated-temperature service, offering better strength, creep resistance, and oxidation resistance compared to carbon steels.
This material is especially suited for refinery piping, steam lines, pressure vessels, and other high-temperature industrial environments.
Key Features
Excellent high-temperature strength and stability
Good creep resistance for long-term service
Improved oxidation and scaling resistance
Suitable for forged components such as flanges & fittings
Good fabrication and weldability with proper heat treatment
Cost-effective compared to stainless steels for similar temperature ranges
Specification
| Specification | Details |
|---|---|
| Standard | ASTM A182 / ASME SA182 |
| Grade | F12 (Class 1 & Class 2) |
| Material Type | Chromium-Molybdenum Alloy Steel |
| UNS Number | K11562 |
| Manufacturing Process | Forged / Rolled |
| Common Forms | Flanges, Forged Fittings, Valves, Rings, Discs |
| Heat Treatment | Annealed / Normalized & Tempered |
| Size Range | ½” to 48″ (Flanges), custom forged sizes available |
Equivalent Grades
| Standard | Grade |
|---|---|
| UNS | K11562 |
| WNR / EN | 1.7335 |
| DIN | 13CrMo44 / 13CrMo4-5 |
| BS | 620 A/B |
| Other | ASTM A336 F12 (for boiler/rotor forgings) |
Available Sizes
Flanges:
½” to 48″
Pressure Classes: 150#, 300#, 600#, 900#, 1500#, 2500#
Forged Fittings:
½” to 4″ (Socket Weld & Threaded)
Bars & Billets:
Dia: 20 mm to 500 mm
(Custom sizes available as per drawing or forging requirement.)
Chemical Composition
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.05 – 0.20 |
| Manganese (Mn) | 0.30 – 0.60 |
| Silicon (Si) | 0.50 – 1.00 |
| Chromium (Cr) | 1.00 – 1.50 |
| Molybdenum (Mo) | 0.44 – 0.65 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.030 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 380–585 MPa |
| Yield Strength (0.2% Offset) | Min. 205 MPa |
| Elongation | Min. 22% |
| Hardness | Max. 187 HB (Class 1), Max. 223 HB (Class 2) |
Physical Properties
| Property | Value (Typical) |
|---|---|
| Density | 7.85 g/cm³ |
| Modulus of Elasticity | 200 GPa |
| Thermal Conductivity | ~ 42 W/m·K |
| Specific Heat | 460 J/kg·K |
| Melting Range | 1425 – 1460°C |
Types / Forms Available
Weld Neck Flanges
Slip-On Flanges
Blind Flanges
Socket Weld Flanges
Threaded Flanges
Forged Elbows, Tees & Reducers
Valve Bodies & Components
Rings, Discs & Custom-Forged Shapes
Corrosion Resistance
Provides good resistance to oxidation and scaling in high-temperature environments
Not suitable for wet corrosive or chloride-rich environments
Performs well in steam, hot gases, and moderate sulfur environments
Heat Resistance
Designed for high-temperature service up to 500–600°C
Stable mechanical strength in steam lines & pressure piping
Good creep strength ensures long-term durability
Chromium improves oxidation resistance during continuous temperature cycles
Heat Treatment
Annealing: 760–900°C followed by slow cooling
Normalizing & Tempering (Class 2):
Normalize: 900–950°C
Temper: 650–760°C
PWHT may be required after welding based on service conditions
Welding & Fabrication
Can be welded using standard alloy steel welding procedures
Suitable filler metals: ER/F 9Cr-1Mo or equivalent
Preheat recommended (150–300°C depending on thickness)
PWHT required to restore toughness & reduce hardness
Good machinability in the annealed condition
Applications
- Oil & Gas
High-pressure flanges
Forged fittings
Hot hydrocarbon lines
- Power Plants
Steam pipelines
Turbine casing parts
Boiler components
- Petrochemical & Refineries
Reactor lines
Furnace & heater tubes
High-temperature valve parts
Heat exchangers
Pressure vessels
Manifolds & header systems