Alloy steel flanges are important connecting components commonly used to join pipelines, valves, and other equipment. Unlike ordinary flanges, alloy steel flanges are made from high-strength, highly corrosion-resistant alloy steel materials. They offer excellent mechanical properties and corrosion resistance, making them suitable for demanding conditions involving high temperature, high pressure, and strong corrosive environments.
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Main Characteristics of Alloy Steel Flanges:
High Strength: The alloy steel material offers excellent strength and rigidity, ensuring the stability and reliability of the connection.
Durability: The addition of alloying elements enhances the overall durability and service life of the flange, especially under harsh working conditions.
Corrosion Resistance: Alloy steel can withstand long-term exposure to highly corrosive media such as acids, alkalis, and seawater without deterioration.
High-Temperature Performance: Alloy steel flanges maintain stable performance even in high-temperature environments.
Weldability: Most alloy steels used for flanges offer good weldability, making installation into piping systems more convenient.
What are the Grades of Alloy Steel Flanges?(ASTM A182)
F5 : A chromium-molybdenum alloy steel with enhanced high-temperature strength, suitable for high-temperature applications.
F9 : A chromium-molybdenum alloy steel that offers improved creep resistance and high-temperature corrosion resistance, commonly used in refineries and power plants.
F11 : A low alloy steel with enhanced creep resistance, available in three classes: Class 1, Class 2, and Class 3.
F22 : A chromium-molybdenum alloy steel known for its excellent creep strength, oxidation resistance, and corrosion resistance.
F91 : A high-strength low alloy steel featuring good toughness and high-temperature strength, suitable for power generation and petrochemical applications.
F92 : A high performance ferritic alloy steel grade designed for high temperature and high pressure applications, especially in power plants and the petrochemical industry.
Chemical Composition of ASTM A182 Alloy Steel Flanges
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | Cb |
| ASTM A182 F5 | MIN | 0.30 | 4.00 | 0.44 | ||||||
| MAX | 0.15 | 0.60 | 0.030 | 0.030 | 0.50 | 0.50 | 6.00 | 0.65 | ||
| ASTM A182 F9 | MIN | 0.30 | 0.50 | 8.00 | 0.90 | |||||
| MAX | 0.15 | 0.60 | 0.030 | 0.030 | 1.00 | 10.00 | 1.10 | |||
| ASTM A182 F11 CL1 | MIN | 0.05 | 0.30 | 0.50 | 1.00 | 0.44 | ||||
| MAX | 0.15 | 0.60 | 0.03 | 0.03 | 1.00 | 1.50 | 0.65 | |||
| ASTM A182 F11 CL2 | MIN | 0.10 | 0.30 | 0.50 | 1.00 | 0.44 | ||||
| MAX | 0.20 | 0.80 | 0.04 | 0.04 | 1.00 | 1.50 | 0.65 | |||
| ASTM A182 F11 CL3 | MIN | 0.05 | 0.30 | 0.50 | 1.00 | 0.44 | ||||
| MAX | 0.15 | 0.60 | 0.03 | 0.03 | 1.00 | 1.50 | 0.65 | |||
| ASTM A182 F12 CL1 | MIN | 0.05 | 0.30 | 0.80 | 0.44 | |||||
| MAX | 0.15 | 0.60 | 0.45 | 0.45 | 0.50 | 1.25 | 0.65 | |||
| ASTM A182 F12 CL2 | MIN | 0.10 | 0.30 | 0.10 | 0.80 | 0.44 | ||||
| MAX | 0.20 | 0.80 | 0.40 | 0.40 | 0.60 | 1.25 | 0.65 | |||
| ASTM A182 F22 CL1，CL3 | MIN | 0.05 | 0.30 | 2.00 | 0.87 | |||||
| MAX | 0.15 | 0.60 | 0.04 | 0.04 | 0.50 | 2.50 | 1.13 | |||
| ASTM A182 F91 | MIN | 0.08 | 0.30 | 0.02 | 8.00 | 0.85 | 0.06 | |||
| MAX | 0.12 | 0.60 | 0.02 | 0.01 | 0.50 | 0.40 | 9.50 | 1.05 | 0.10 | |
| ASTM A182 F92 | MIN | 0.07 | 0.30 | 8.50 | 0.30 | 0.04 | ||||
| MAX | 0.13 | 0.60 | 0.02 | 0.01 | 0.50 | 0.40 | 9.50 | 0.60 | 0.09 |
Mechanical Property of ASTM A182 Alloy Steel Flanges
| MATERIAL | ASTM A182 F5 | ASTM A182 F9 | ASTM A182 F12 CL1 | ASTM A182 F12 CL2 | ASTM A182 F11 CL1 | ASTM A182 F11 CL2 | ASTM A182 F11 CL3 | ASTM A182 F12 CL1 | ASTM A182 F12 CL2 | ASTM A182 F22 CL1 | ASTM A182 F22 CL3 | ASTM A182 F91 | ASTM A182 F92 |
| T.S (MPA) | 485 min | 585 min | 415 min | 485 min | 415 min | 485 min | 515 min | 415min | 485min | 415min | 515min | 620min | 620min |
| Y.S (MPA) | 275 min | 380 min | 220 min | 275 min | 205 min | 275 min | 310 min | 220min | 275min | 205min | 310min | 415min | 440min |
| EL % | 20 min | 20 min | 20 min | 20 min | 20 min | 20 min | 20 min | 20min | 20min | 20min | 20min | 20min | 20min |
| R/A % | 35 min | 40 min | 45 min | 30 min | 45 min | 30 min | 30 min | 45min | 30min | 35min | 30min | 40min | 45min |
| HARDNESS | 143-217 | 179-217 | 121-174 | 143-207 | 121-174 | 143-207 | 150-207 | 121-174 | 143-207 | 170 | 156-207 | 190-248 | 269 |
Different Types of Alloy Steel Flanges
Weld neck flange refers to a flange with a neck and a groove on the outside of the neck, which is used for butt welding with pipes or equipment.
2. Blind Flange
Blind flange is a type of flange connection. In fact, it is a flange without a hole in the middle. It is usually fixed to the flange of the pipe or equipment by bolts, and a gasket is used between the two to achieve sealing.
Socket welding flange is a type of flange that is welded by inserting the end of the pipe into the socket hole of the flange and then performing annular fillet weld.
Threaded flange is a non-welded flange that processes the inner hole of the flange into a pipe thread and connects it with a threaded pipe.
Slip on flange refers to a type of flange that is welded by putting the flange on the end of the pipe and then performing annular fillet welds on the inside and outside of the flange.
The lap joint flange is not directly welded to the pipe, but is connected to the pipe through a flanged nipple.
Manufacturing of Alloy Steel Flanges:
The manufacturing of alloy steel flanges typically involves forging. This process shapes the heated alloy steel billet under high pressure, resulting in a dense, strong, and durable flange with excellent grain flow. Manufacturers then machine the flanges to the required dimensions and tolerances according to relevant standards like ASME B16.5 or other specific requirements. They may also apply heat treatment processes to achieve the desired mechanical properties.
When selecting alloy steel flanges, it is crucial to consider the specific application requirements, including pressure, temperature, fluid media, and relevant industry standards, to ensure the selection of the appropriate grade and type of flange for safe and efficient operation.
Advantages of Using Alloy Steel Flanges
1. High Strength and Toughness
Alloy steel flanges offer superior tensile strength and impact resistance compared to carbon steel.
2. Excellent High-Temperature Performance
Maintain mechanical properties and dimensional stability at elevated temperatures.
Suitable for boilers, heat exchangers, and power generation systems.
3. Enhanced Corrosion Resistance
Chromium, molybdenum, and other alloying elements provide resistance
4. Long-Term Durability
Resistant to wear, fatigue, and thermal degradation.
Reduces maintenance costs and downtime over time.
5. Good Weldability and Machinability
Most alloy steel grades are weldable and can be easily machined to precise specifications.Facilitates custom fabrication and easy integration into complex piping systems.
6. Versatility
Used in sectors like oil & gas, chemical processing, aerospace, nuclear, and marine.
Alloy Steel Flanges for High-Pressure Applications
Off-Shore Oil Drilling Companies
Power Generation
Petrochemicals
Gas Processing
Specialty Chemicals
Pharmaceuticals
Pharmaceutical Equipment
Chemical Equipment
Sea Water Equipment
You can Get an Offer for Products in Below Material Forms:
-Pipe and Tube (EN 10216-5, ASTM A213, ASTM A249, A312, A790,)
-Forged Fitting and Flange (ASTM A182 , ASTM A105,ASTM B564 )
-Butt Weld Fittings (ASTM A234, ASTM A403,ASTM A815)
-Round bar , Billet (ASTM A276, ASTM A479)
– Plate, Sheet, Strip(ASTM A240, EN 10028-7, A480)
-Bolting, Nuts（ASTM A193, A194, A320）
Alloy Steel Flanges Exported Countries
We Export Alloy Steel Flanges to Saudi Arabia, United Arab Emirates, Qatar, Bahrain, Oman, Kuwait, Turkey, Egypt, Yemen , Syria, Jordan, Cyprus, Singapore, Malaysia, Indonesia, Thailand, Vietnam, South Korea, Japan, Sri Lanka, Maldives, Bangladesh, Cambodia, Argentina, Bolivia, Brazil, Venezuela, Colombia, Ecuador, Guyana, Paraguay, Uruguay, United States Of America, Canada, Mexico, Panama, Jamaica, Bahamas, Denmark, Norway, Germany, France,Italy, United Kingdom, Spain, Belgium, Greece, Czech Republic, Portugal, Hungary, Albania, Austria, Finland, Ireland, Croatia, Malta, Nigeria, Algeria, Angola, South Africa, Libya, Egypt, Sudan, Europe, Africa, Asia, North America, South America, Middle East.etc
We are professional in manufacturing and exporting flanges in various materials.
