ASTM A182 F347H
ASTM A182 F347H Stainless Steel Flange
Emirerri Steel offers premium-quality ASTM A182 F347H Stainless Steel Flanges, designed for high-temperature and corrosion-resistant applications. F347H is a titanium-stabilized austenitic stainless steel, which prevents intergranular corrosion and maintains excellent mechanical properties at elevated temperatures.
These flanges are widely used in power plants, chemical industries, refineries, and high-temperature processing units, where durability, strength, and resistance to oxidation are critical.
Key Features
Titanium-Stabilized: Minimizes carbide precipitation and prevents intergranular corrosion.
High-Temperature Strength: Retains mechanical integrity at elevated temperatures.
Excellent Oxidation & Scaling Resistance for prolonged service life.
Superior Corrosion Resistance in oxidizing and mildly reducing environments.
Good Weldability & Fabrication Characteristics.
Durable and Reliable for critical industrial applications.
Specification
| Standard | Details |
|---|---|
| Product Standard | ASTM A182 / ASME SA182 |
| Grade | F347H |
| UNS Number | S34709 |
| Material Type | Austenitic Stainless Steel (Titanium Stabilized) |
| Manufacturing Process | Forged / Rolled / Heat Treated |
| Delivery Condition | Solution Annealed |
| Form | Flanges (WNRF, SORF, Slip-On, Blind, Lap Joint) |
Equivalent Grades
| Standard | Equivalent Grade |
|---|---|
| UNS | S34709 |
| EN / DIN | X6CrNiNb18-10 / 1.4550 |
| BS | 347H |
| JIS | SUS 347H |
| AFNOR | Z6CN18-12 |
Available Sizes
| Type of Flange | Size Range |
|---|---|
| Welding Neck (WN) | ½” to 48” (Class 150 – 2500) |
| Slip-On (SO) | ½” to 48” |
| Socket Weld (SW) | ½” to 4” |
| Blind (BL) | ½” to 48” |
| Lap Joint (LJ) | ½” to 48” |
Chemical Composition
| Element | Percentage (%) |
|---|---|
| Carbon (C) | 0.04 max |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 1.00 max |
| Chromium (Cr) | 17.00 – 19.00 |
| Nickel (Ni) | 9.00 – 13.00 |
| Titanium (Ti) | ≥ 5×C, typically 0.70 max |
| Phosphorus (P) | 0.045 max |
| Sulfur (S) | 0.03 max |
| Nitrogen (N) | 0.10 max |
| Iron (Fe) | Balance |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength (MPa) | 515 min |
| Yield Strength (MPa) | 205 min |
| Elongation (%) | 40 min |
| Hardness (Brinell) | 217 max |
| Modulus of Elasticity (GPa) | 200 |
Physical Properties
| Property | Value |
|---|---|
| Density | 7.9 g/cm³ |
| Melting Point | 1400 – 1450°C |
| Thermal Conductivity (at 100°C) | 16 W/m·K |
| Electrical Resistivity (20°C) | 0.75 µΩ·m |
| Coefficient of Expansion (20–100°C) | 16.0 µm/m·°C |
Types of F347H Stainless Steel Flanges
Welding Neck Flanges (WN)
Slip-On Flanges (SO)
Socket Weld Flanges (SW)
Blind Flanges (BL)
Lap Joint Flanges (LJ)
Custom Machined Flanges
Corrosion Resistance
F347H flanges offer excellent resistance to intergranular corrosion, oxidation, and scaling. Titanium stabilization prevents sensitization during welding, ensuring long-term reliability in high-temperature and chemically aggressive environments.
Heat Resistance
Continuous Service: Up to 870°C (1600°F)
Intermittent Service: Up to 925°C (1700°F)
Maintains mechanical strength and oxidation resistance under cyclic thermal conditions.
Heat Treatment
Solution Annealing: 1010–1120°C followed by rapid water or air quenching.
Purpose: Restores corrosion resistance and mechanical properties after fabrication or welding.
Welding
F347H can be welded using TIG, MIG, or SMAW techniques. Use fillers such as ER347 for maintaining corrosion resistance and structural integrity. No post-weld heat treatment is generally required.
Fabrication
Hot Working: 950–1200°C
Cold Working: Possible with higher force; maintains high strength
Post-Fabrication Annealing: Recommended to restore full corrosion resistance after welding or machining
Applications
Furnace and Heat Treatment Equipment
Power Plants and Boilers
Chemical & Petrochemical Processing Equipment
Marine and Offshore High-Temperature Applications
Laboratory and Industrial Reactors
Gas Turbines and Aerospace Components