15NiCuMoNb5-6-4 Alloy Steel Pipe

High-strength Seamless Pipe For Boiler Systems

15nicumonb5-6-4 seamless alloy steel pipe offers superior corrosion resistance and high-temperature strength for boiler and power plant pipelines up to 500°c.

Pipeline Corrosion Protection Boiler Pipeline Steel High-Temperature Steel Ni-Cu-Mo Alloy +1 More

15NiCuMoNb5-6-4 Alloy Steel Pipe

High-strength Seamless Pipe For Boiler Systems

15nicumonb5-6-4 seamless alloy steel pipe offers superior corrosion resistance and high-temperature strength for boiler and power plant pipelines up to 500°c.

Pipeline Corrosion Protection Boiler Pipeline Steel High-Temperature Steel Ni-Cu-Mo Alloy +1 More

15NiCuMoNb5-6-4, also known as WB36, is a bainitic Ni-Cu-Mo steel micro-alloyed with niobium, developed for pipeline corrosion protection and boiler pipeline steel applications. Conforming to EN 10216-2, ASTM A213 T36, and ASTM A335 P36 standards, it is ideal for high-pressure, high-temperature environments up to 500°C in power plants, petrochemical industries, and nuclear facilities.

The alloy’s composition, including nickel (1.00-1.30%), copper (0.50-0.80%), molybdenum (0.25-0.50%), and niobium (0.015-0.045%), enhances its high-temperature steel properties, such as creep resistance and oxidation resistance. It is used in boiler drums, steam separators, headers, steam generators, and steam pipelines, ensuring reliability in industrial piping solutions.

Manufactured via hot-rolled or cold-drawn processes, 15NiCuMoNb5-6-4 undergoes normalizing and tempering to achieve a bainite + ferrite + sorbite microstructure. It undergoes rigorous testing, including ultrasonic, hydrostatic, and flattening tests, to meet standards. Welding requires preheating (150-200°C) and post-weld heat treatment (590-610°C) to ensure weld integrity. Available in sizes from 10.2-711mm OD and 1.6-100 karmel wall thickness, with lengths up to 16,000mm, it supports customization and U-bending.

Compared to ASTM A335 P9 and P11, 15NiCuMoNb5-6-4 offers a cost-effective balance of strength and corrosion resistance, making it ideal for high-pressure boiler systems. Its equivalents, such as 15Ni1MnMoNbCu (China), provide flexibility, but substitution requires evaluation. This high-temperature steel ensures safety and longevity in demanding environments.

Chemical Composition (typical % by weight)
Element	Content (%)
Carbon (C)	0.03 – 0.08
Nickel (Ni)	5.0 – 6.5
Copper (Cu)	4.5 – 6.0
Molybdenum (Mo)	0.8 – 1.2
Niobium (Nb)	0.05 – 0.10
Manganese (Mn)	0.30 – 0.70
Silicon (Si)	≤ 0.35
Phosphorus (P)	≤ 0.025
Sulfur (S)	≤ 0.015

Mechanical Properties (typical room temperature)
Property	Value
Yield Strength	≥ 275 MPa
Tensile Strength	450 – 600 MPa
Elongation	≥ 25 %
Impact (Charpy V‑Notch)	≥ 34 J @ –196 °C

Global Equivalent Grades for 15NiCuMoNb5-6-4 Alloy Pipe
Country	Standard	Equivalent Grade
Germany	DIN EN 10216-4	15NiCuMoNb5-6-4
France	NF A 36-205	15D3 (with NiCuMoNb)
USA	ASME SA/ASTM A333 Grade 8 / Grade 3 (partial)	Low Temp Nickel Steel
Russia	GOST	09MnNiCuMoNb
China	GB/T	15NiCuMoNb5 (相近成分)

Available Heat Treatment Conditions
Condition	Code	Description
Normalized	N	Heat treated above critical temperature and air cooled
Quenched and Tempered	QT	Heat treated and tempered for improved strength and toughness
Annealed	A	Softened for improved machinability and ductility

Recommended Welding Parameters
Process	Preheating Temp	Interpass Temp	Post-weld Heat Treatment (PWHT)
GTAW / TIG	150 – 200°C	≤ 250°C	620 – 700°C / 1 – 2 hrs
SMAW / Stick	160 – 200°C	≤ 250°C	Required for wall >12 mm

What are the grades of alloy steel?

Alloy steel pipes are categorized by both standards and grades, each designed for specific performance requirements and applications. Common standards include ASTM A335, A519, and A213, while grades like P5, P9, P11, P22, and P91 are frequently used within these standards.

Detailed Grades of Alloy Steel Pipes by Standard
Standard	Detailed Grades	Main Applications
ASTM A335 / ASME SA335	P1, P2, P5, P9, P11, P12, P15, P21, P22, P23, P24, P36, P91, P92, P122, P911	High-temperature pressure systems: power plants, refineries, and chemical plants
ASTM A213 / ASME SA213	T2, T5, T5b, T9, T11, T12, T17, T22, T23, T24, T91, T92, T122, T911	Boiler tubes, superheaters, and heat exchangers
ASTM A519	4130, 4135, 4140, 4145, 4150, 1020, 1026, 1330, 8620	Mechanical tubing, structural applications, automotive components
API 5L	A25, A, B, X42, X46, X52, X56, X60, X65, X70, X80, X100	Oil and gas transmission pipelines (onshore and offshore)
EN 10216‑2	13CrMo4-5, 10CrMo9-10, 12CrMo19-5, X10CrMoVNb9-1, X11CrMo5, 14MoV6-3, X20CrMoV12-1	European pressure vessels and high-temperature piping
GB / SH Standards	15CrMoG, 12Cr1MoVG, 10CrMo910, 12CrMo, 1Cr5Mo, WB36, 10Cr9Mo1VNb (equiv. T91)	Petrochemical, power generation, high-pressure boilers in Chinese systems

Alloy steel is made by combining carbon steel with one or several alloying elements, such as titanium, copper, chromium, aluminum, manganese, silicon, and nickel. This produces specific properties that are not found in standard carbon steel. Common alloy steel grades include 4130, 4140, 4340, and 8620 for their balance of characteristics like strength, toughness, machinability, and weldability.

Alloy steel pipes are made from carbon steel combined with alloying elements like chromium, molybdenum, nickel, or vanadium to improve strength, heat resistance, and corrosion performance—suitable for challenging industrial applications.

Common standards include ASTM A335/ASME SA335 (P1, P5, P9, P11, P22, P91, P92), ASTM A213 (T5, T9, T11, T22, T91), as well as EN 10216‑2 (e.g., 13CrMo4‑5).

They’re available as seamless, ERW, LSAW, SSAW, and CD pipes. Typical processes include hot or cold finishing, with precise control for pressure/temperature specifications.

Available diameters span 1/8″–42″ (OD ~6–1067 mm), wall thicknesses from schedule 20 to XXS or custom. Lengths include SRL, DRL, or fixed lengths up to 23m.

Surfaces may be epoxy-coated, varnished, oil-treated, galvanized, or shot-blasted. Inspection includes PMI, tensile, hardness, impact, flaring, flattening, hydrostatic, and NDT testing.

Widely used in power generation (boilers, superheaters), petrochemical plants, refineries, oil & gas pipelines, aerospace, and industrial machinery where heat, pressure, and corrosion demand superior performance.

Pipes are delivered in conditions such as cold-finished/hard (BK), cold-finished/soft (BKW), annealed (GBK), or normalized (NBK), with certificate and traceability of heat/furnace number.

Alloy steel pipes contain alloying elements that enhance their strength, hardness, and resistance to wear and corrosion. Carbon steel pipes, on the other hand, primarily consist of carbon and iron, making them more susceptible to corrosion and wear.

Selecting the right alloy steel pipe involves considering factors such as the operating temperature, pressure, corrosion environment, and mechanical stress. It's essential to consult with material experts and refer to relevant standards to ensure compatibility with your specific application.

Yes, alloy steel pipes are designed to withstand high temperatures and are commonly used in applications such as power plants, boilers, and heat exchangers, where elevated temperatures are prevalent.

Alloy Steel Pipe Industry Applications

Alloy steel pipes offer superior strength, temperature and corrosion resistance, making them ideal for demanding environments across energy, petrochemical, construction, and more.

Oil & Gas Industry

Used extensively in drilling, subsea and onshore pipelines for crude oil, natural gas, and refined products due to high strength and corrosion resistance.

Chemical & Petrochemical Plants

Ideal for transporting corrosive chemicals, high-pressure reactor feeds, and heat exchanger tubing where carbon steel fails.

Power & Utility Boilers

Used in high-temp boiler tubes, superheaters, reheaters, and steam piping; withstands extreme temperatures and pressures efficiently.

Construction & Infrastructure

Used as structural pipelines, piling tubes, and transport lines in high-rise buildings and bridges due to high structural strength.

Cryogenic & Low-Temperature Services

Suitable for transporting liquefied gases and cold media, where toughness and strength must endure sub-zero temperatures.

Energy & Environmental Efficiency

Alloy steel pipes are fully recyclable and support energy-efficient systems, aligning with green standards in modern industry.

Key Considerations

Service Conditions: Choose grade based on temperature, pressure, and fluid compatibility.
Fabrication & Welding: Follow proper heat treatment and filler materials to avoid cracking or weakening.
Inspection & Maintenance: Regular checks for corrosion, fatigue, wear — especially in high-stress environments.

15NiCuMoNb5-6-4 Alloy Steel Pipe

15NiCuMoNb5-6-4 Alloy Steel Pipe

What are the grades of alloy steel?