GOST 550-75 15X5M Pipe | 15Х5М Seamless Alloy Steel Pipe | ASTM A335 P5 Equivalent

GOST 550-75 15X5M seamless pipe is a chromium-molybdenum low alloy steel pipe developed for petroleum refining, petrochemical processing, and high-temperature service applications.

Known in Russian standards as 15Х5М (15Kh5M), this alloy steel pipe contains approximately 5% chromium and 0.5% molybdenum, providing excellent oxidation resistance, high-temperature strength, and long-term stability under elevated operating temperatures.

15X5M alloy steel pipes are widely used in:

  • Oil refineries
  • Petrochemical plants
  • Catalytic cracking units
  • Hydrogen processing units
  • High-temperature process piping
  • Heat exchangers
  • Furnace tubes

We are a professional supplier and exporter of:

  • GOST 550-75 15X5M Pipe
  • 15Х5М Seamless Pipe
  • 15Cr5Mo Alloy Steel Pipe
  • ASTM A335 P5 Equivalent Pipe
  • 5Cr-0.5Mo Seamless Pipe
  • Refinery Process Steel Tubes

from China.


What is GOST 550-75?

GOST 550-75  is the Russian standard covering:

Seamless steel tubes for petroleum processing and petrochemical industries.

The standard specifies:

  • Hot-finished seamless pipes
  • Cold-drawn seamless pipes
  • Warm-worked seamless pipes

used in:

  • Refinery units
  • Petrochemical facilities
  • High-temperature process systems

Pipes are supplied in Group A and Group B according to manufacturing and inspection requirements.


What is 15X5M Steel?

15Х5М (15Kh5M) is a low-alloy chromium-molybdenum steel designed for elevated temperature service.

The alloy contains:

  • Chromium: 4.5–6.0%
  • Molybdenum: 0.45–0.60%

which provide:

  • High temperature oxidation resistance
  • Good creep resistance
  • Sulfidation resistance
  • Long service life in refinery environments

15Х5М is commonly considered the Russian equivalent of:

  • ASTM A335 P5
  • ASTM A213 T5
  • DIN 1.7362
  • X12CrMo5
  • 5Cr-0.5Mo Steel

GOST 550-75 15X5M Pipe Specification

Item Description
Standard GOST 550-75
Material 15Х5М (15Kh5M)
Equivalent Grade ASTM A335 P5
Product Type Seamless Pipe
Manufacturing Method Hot Finished / Cold Drawn
Pipe Form Round Seamless
Ends Plain End / Bevel End
Length 4m – 12m
Inspection EN10204 3.1

Equivalent Grades of 15X5M

Standard Grade
GOST 15Х5М
ASTM A335 P5
ASTM A213 T5
DIN/WNr 1.7362
DIN X12CrMo5
EN 5CrMo16
JIS STPA25
JIS STBA25
GB/T 12Cr5Mo
UNS K41545

Chemical Composition of 15X5M Steel

Element %
Carbon (C) ≤0.15
Silicon (Si) ≤0.50
Manganese (Mn) ≤0.50
Nickel (Ni) ≤0.60
Sulfur (S) ≤0.025
Phosphorus (P) ≤0.030
Chromium (Cr) 4.5–6.0
Molybdenum (Mo) 0.45–0.60
Copper (Cu) ≤0.20
Titanium (Ti) ≤0.03
Vanadium (V) ≤0.05

The high chromium content significantly improves oxidation and corrosion resistance at elevated temperatures.


Mechanical Properties of GOST 550-75 15X5M Pipe

Property Value
Tensile Strength ≥392 MPa
Yield Strength ≥216 MPa
Elongation ≥22%
Reduction of Area ≥50%
Impact Toughness (KCU) ≥1180 kJ/m²
Hardness ≤170 HB

These properties provide excellent performance under thermal cycling and refinery operating conditions.


Heat Treatment

15X5M pipes are typically supplied in the annealed condition.

Annealing Parameters

Treatment Temperature
Annealing 840–870°C
Cooling Furnace Cooling / Air Cooling

Heat treatment improves:

  • Microstructure stability
  • Weldability
  • High-temperature strength
  • Service life

High Temperature Performance

15Х5М alloy steel is specifically designed for:

  • 400°C – 650°C service
  • Refinery furnace piping
  • Hydroprocessing units
  • Catalytic reformers

The chromium and molybdenum combination provides:

  • Oxidation resistance
  • Sulfidation resistance
  • Hydrogen attack resistance
  • Creep resistance

Weldability

15Х5М is considered:

Conditionally Weldable

Recommended procedures include:

  • Preheating before welding
  • Controlled welding parameters
  • Post Weld Heat Treatment (PWHT)

This helps prevent:

  • Cold cracking
  • Heat-affected zone embrittlement

Inspection and Testing

All GOST 550-75 15X5M pipes can be supplied with:

  • Chemical analysis
  • Mechanical testing
  • Hardness testing
  • Hydrostatic testing
  • Ultrasonic Testing (UT)
  • Eddy Current Testing (ET)
  • PMI Testing
  • Dimensional inspection

Certificates:

  • EN 10204 3.1
  • Third-party inspection available

Applications of GOST 550-75 15X5M Pipe

Petroleum Refining

Used in:

  • Crude distillation units
  • Catalytic cracking units
  • Hydrocrackers

Petrochemical Plants

Suitable for:

  • Process piping
  • High-temperature reactors
  • Furnace systems

Heat Exchangers

Used for:

  • High-temperature heat transfer systems
  • Process heaters

Power Generation

Applied in:

  • Steam lines
  • Superheater systems

ASTM A335 P5 vs 15X5M

Property 15X5M ASTM A335 P5
Chromium 4.5–6.0% 4–6%
Molybdenum 0.45–0.60% 0.45–0.65%
Service Temperature Up to 650°C Up to 650°C
Refinery Service Excellent Excellent
Equivalent Yes Yes

15Х5М is widely accepted as the Russian equivalent of ASTM A335 P5 for refinery applications.


Example Ordering Information

Product: Seamless Alloy Steel Pipe
Standard: GOST 550-75
Material: 15Х5М (15X5M)
Equivalent Grade: ASTM A335 P5
Size: 6 Inch
Wall Thickness: SCH STD
Length: 6000 mm
Ends: Beveled Ends (BE)
Certificate: EN10204 3.1
Quantity: As Required


Frequently Asked Questions

What is 15X5M pipe equivalent to?

15Х5М is generally considered equivalent to ASTM A335 P5 and ASTM A213 T5 chromium-molybdenum alloy steel.

What is GOST 550-75?

GOST 550-75 is the Russian standard for seamless steel tubes used in petroleum refining and petrochemical industries.

What is the operating temperature of 15X5M steel?

Typically up to 650°C for long-term service.

Is 15X5M suitable for refinery applications?

Yes. It is specifically developed for refinery and petrochemical processing units.

Can 15X5M pipe be supplied with EN10204 3.1 certificates?

Yes. EN10204 3.1 and third-party inspection reports are available.


ASTM A335 P5 Seamless steel pipes A335 Gr P5 Pipe

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