1. Core Information: Designation
Standard System: German DIN / European EN standard.
Material Number: 1.5682 (This is the primary identifier).
Steel Grade: Commonly corresponds to 13CrMo4-5 or 16CrMo4, depending on the delivery condition and standard version.
Material Type: Chromium-Molybdenum Alloy Steel, classified as a heat-resistant steel for medium-temperature service.
2. Typical Chemical Composition (%)
This is a low-alloy steel where Chromium (Cr) and Molybdenum (Mo) are key for enhanced high-temperature properties.
Carbon (C): 0.10 - 0.18
Silicon (Si): ≤ 0.35
Manganese (Mn): 0.40 - 0.70
Phosphorus (P): ≤ 0.025
Sulfur (S): ≤ 0.020
Chromium (Cr): 0.70 - 1.00 (Improves oxidation & corrosion resistance, high-temperature strength)
Molybdenum (Mo): 0.40 - 0.50 (Significantly enhances high-temperature strength and creep resistance)
3. Key Characteristics & Properties
Excellent High-Temperature Properties: Maintains good creep strength and long-term strength at elevated temperatures (typically up to 550°C - 580°C), which is the most critical property for boiler tubes.
Good Oxidation Resistance: Chromium aids in forming a protective oxide layer in steam or flue gas environments.
Good Weldability and Hot Workability: Can be welded satisfactorily with proper preheating and post-weld heat treatment (PWHT).
Moderate Corrosion Resistance: Offers better resistance to water/steam corrosion compared to plain carbon steels.
4. Primary Applications
Specifically designed for high-temperature and high-pressure components:
Power Station Boilers: Superheater tubes, reheater tubes, headers, main steam pipes.
Industrial Boilers: Heating surface tubes in high-temperature sections.
Petrochemical Plants: Tubes for high-temperature cracking furnaces, reformer furnaces.
Piping and Pressure Vessels in other high-temperature/pressure equipment.
5. Relevant Standards & Delivery Condition
Product Standard:
EN 10216-2: Seamless steel tubes for pressure purposes - Part 2: Non-alloy and alloy steel tubes with specified elevated temperature properties.
DIN 17175: Heat-resisting seamless steel tubes (older standard, largely superseded by EN).
Delivery Condition: Usually supplied in normalized + tempered condition to ensure optimal microstructure and mechanical properties for high-temperature service.
6. Equivalent / Comparable Grades
International Comparison:
USA (ASTM/ASME): A335 P11 or A213 T11 are the closest equivalents.
China (GB): 15CrMoG is the most similar and widely used grade in domestic power plants.
Japan (JIS): STBA 22 or STPA 22.
Summary
1.5682 (13CrMo4-5) is a classic and reliable chromium-molybdenum heat-resistant steel. It is a key material for manufacturing medium-temperature, high-pressure boiler and pressure vessel tubing. Its core advantage lies in its creep resistance and long-term stability under prolonged high-temperature service.
When sourcing or using this material, it is crucial to confirm the exact product standard (e.g., EN 10216-2), delivery specifications, and required inspection/test certificates to ensure full compliance with design and operational requirements.
