Core definitions and application scenarios

High-pressure alloy elbow pipes are made of alloy steel (containing alloy elements such as Cr, Mo, V, and Nb) and are used for elbow pipes in high-pressure (≥10MPa), high-temperature, corrosive or alternating load working conditions. Its core advantage lies in:

High strength: Yield strength ≥355MPa (such as 15CrMo alloy elbow pipe), which is more than 1.5 times that of ordinary carbon steel;

High-temperature resistance: It can work for a long time at 500-650℃ (for example, the P91 alloy elbow pipe can withstand a temperature of up to 620℃).

Corrosion resistance: Resistant to media such as H₂S, CO₂, and Cl⁻ (for example, the pitting corrosion equivalent PREN of 22Cr duplex steel elbow pipe is ≥32).

Typical application scenarios

Power industry: Main steam pipeline of supercritical power station (pressure 25MPa, temperature 566℃);

Petrochemical industry: High-pressure pipe of hydrocracking unit (H₂ partial pressure 15MPa, temperature 480℃);

Marine engineering: Deep-sea oil and gas risers (pressure 100MPa, containing H₂S/CO₂ mixed medium);

Hydrogen energy storage and transportation: High-pressure hydrogen pipelines (70MPa, -40℃ low-temperature environment).

The role of alloying elements

Cr: Forms an oxide film to enhance high-temperature oxidation resistance (for example, 5% Cr enables a temperature resistance of up to 600℃);

Mo: Inhibits creep and enhances high-temperature strength (1% Mo increases strength at 500℃ by 30%);

V/Nb: Refine the grain structure and improve fatigue resistance (increase fatigue limit by 20%).