Alloy Steel P91 Tubes are tubular and contain larger concentrations of alloying elements such as molybdenum (Mo), chromium (Cr), nickel, etc. than conventional carbon steel pipes. “Low-Alloy” steel Tube, or pipes with a total amount of alloying elements below 5%, are cover by ASTM A335.
Transformation of steel in higher alloys, such as stainless steel, duplex, super-alloy materials like Inconel, Hastelloy, Monel, etc., occurs when alloy elements (for instance, Nickel and Chromium) are add in greater percentages.
In the energy sector, alloy steel p91 pipes are utilize for applications requiring extremely high pressures, cryogenic service, or high temperatures.
The presence of molybdenum (“Moly”) enhances the steel’s strength and elastic limit, and its wear resistance, impact resistance, and hardenability. And it makes chromium steel less prone to embrittlement, improves the resistance to softening, and avoids pitting. Chromium, a crucial component of stainless steel alloys, keeps the steel from oxidizing at high temperatures and boosts its corrosion resistance. Low-alloy pipes’ tensile, yield, and hardness qualities are improving at room temperature.
Other alloying components that can be found in pipes of all grades to varying degrees include:
Aluminum: Reduces oxygen production between steelmaking
Boron is use to form fine grains and increase the hardness of steel.
Cobalt is use to increase the heat and wear resistance of steel.
Manganese: improves the ability of steel to harden.
At low temperatures, nickel increases toughness, hardenability, and impact strength.
Silicon: reduces oxygen, increases toughness and hardenability
Titanium: inhibits chromium carbide precipitation
Tungsten: improves steel hardness and refines steel grain size, mainly at high temperatures
Vanadium: increases the fatigue resistance of steel.
Specification Of Alloy Steel P91 Tubes
Mechanical Properties Of Alloy Steel P91 Tubes
A335 Low-Alloy Pipe/Tube – P91
UNS Number – K91560
Yield Strength ksi – 60
Tensile Strength ksi – 85
Elongation % – 20
