Alloy Steel Flange

Alloy Steel Flange is a pipeline connector made of alloy steel, which combines high strength, high temperature resistance, corrosion resistance and other characteristics by adding alloy elements such as chromium, molybdenum, nickel, etc. It is widely used in industrial pipeline systems with high temperature, high pressure and complex media.

Material and Performance

Common materials include:

Chromium molybdenum alloys (such as 2.25Cr-1Mo, 9Cr-1Mo): high temperature resistance, creep resistance, and can withstand high pressure (≥ 10MPa) for a long time at 593 ℃;

Nickel based alloys (such as Inconel 625): resistant to strong corrosion, suitable for chlorine containing and acidic media (such as seawater, hydrochloric acid);

Low alloy steel pipes (such as 16Mn): balance strength and cost, suitable for medium pressure (4-10MPa) scenarios.

The alloy element increases the tensile strength of the flange by 30% -50%, and has better impact toughness than carbon steel, which can adapt to temperature fluctuations from -40 ℃ to 650 ℃.

Manufacturing and Specifications

Produced using forging technology, stress is eliminated through heat treatment to ensure material uniformity. The specifications comply with ASME B16.5 and GB/T 9115 standards, covering types such as butt welding and socket welding, with a pressure rating of Class 2500 (42MPa) and diameters ranging from DN15 to DN1200. The sealing surface is mostly concave convex or mortise and tenon groove surface, suitable for metal gaskets to ensure high-pressure sealing.

Applicable scenarios

Main steam pipeline of power plant boiler (9Cr-1Mo flange can withstand high temperature of 540 ℃);

Refining and hydrogenation unit (2.25Cr-1Mo flange resistant to hydrogen corrosion);

Deep sea oil and gas pipeline (Inconel 625 flange resistant to seawater corrosion).

Although the cost is higher than that of carbon steel flanges, it can significantly reduce the risk of leakage under harsh working conditions and is the core component of high-pressure complex systems.