What is p11 material properties

A335 P11 is a high-temperature, high-pressure ferritic alloy seamless steel pipe conforming to the American standard ASTM A335. Its core alloy composition is 1.00%-1.50% chromium (Cr) and 0.44%-0.65% molybdenum (Mo), commonly known as "1.25Cr-0.5Mo alloy pipe". This material is processed through heat treatment processes such as normalizing and tempering, possessing excellent high-temperature strength, oxidation resistance, and sulfide corrosion resistance.

It can operate stably for extended periods in hydrogen-containing environments at 350–480℃, effectively resisting damage from hydrogen embrittlement and hydrogen corrosion. It also has good weldability and formability, meeting processing requirements such as bending and flange connections. Due to its outstanding high-temperature and high-pressure resistance, it has become a core pipe material for critical equipment such as high-pressure boilers and hydrogenation reactors.

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SA335 Gr P11 High Pressure Steel Pipe Material Specification

	1/8NB TO 24NB inch
	ASTM A 335, and ASME SA 335
	19.05milimeter – 114.3milimeter
	2.0milimeter – 14 milimeter
	max 16000milimeter
	Schedule 20 - XXS up to 250 milimeter thk.
	Round, Rectangular, Square, Hydraulic Etc.
	Single, Double Random & Cut to Length.
	Plain, Beveled, Treaded.

 

A335 P11 Alloy Steel Pipe Chemical Composition

UNS Designa-tion	K11597
	0.05-0.60
	0.30-0.60
Phosphorus(max.)	0.025
Sulfur(max.)	0.025
	0.50-1.00
	…
	1.00-1.50
	0.44-0.65
	…

 

Mechanical properties of A335 P11 Alloy Steel Pipe

	415 Mpa
	205 Mpa
	30/20

 

A335 P11 Seamless Ferritic Alloy-Steel Pipe Features

1. : Thanks to the addition of chromium and molybdenum, this steel pipe can operate for extended periods at relatively high temperatures (typically up to approximately 593℃). A stable chromium oxide protective film forms on its surface, slowing down further oxidation.

2. : It possesses sufficient strength, toughness, and creep resistance at both room and high temperatures, capable of withstanding internal medium pressure and external loads.

3. The chromium content provides some resistance to oxidizing environments, but its resistance to highly corrosive media is limited, and it is generally not used in applications where corrosion is a primary concern.

4. A335P11 steel pipe can be cold-bent and cut. Welding requires the use of matching welding materials and preheating and post-heating processes to prevent cold cracking.

 

A335 P11 Heater Tubes Production Process

Hot-rolled (extruded seamless steel pipe): Round billet → heating → piercing → three-roll skew rolling, continuous rolling or extrusion → tube removal → sizing (or reduction) → cooling → billet tube → straightening → hydrostatic test (or flaw detection) → marking → warehousing.

Cold-drawn (rolled) seamless steel pipe: Round billet → heating → piercing → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → billet tube → heat treatment → straightening → hydrostatic test (flaw detection) → marking → warehousing.

 

A335 P11 High Pressure Alloy Steel Seamless Pipe Applications

Its primary service is in industrial piping systems requiring tolerance to medium to high temperatures.

1. Power Industry: In boiler systems of thermal power plants, it is commonly used in the relatively high-temperature sections of superheaters, reheaters, and main steam pipelines to transport high-temperature, high-pressure steam.

2. Petrochemical Industry: In oil refineries and chemical plants, it is used in the manufacture of process pipelines in hydrotreating, catalytic cracking, and other units to transport high-temperature oils, oil gases, or other process fluids.

3. Other Industries: It can also be used in piping of certain industrial boilers and tube bundles of heat exchangers.

 

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