What is 16Mo3 filler material?
16Mo3 is a EN10028 specified pressure vessel grade chrome molybdenum steel alloy for use in elevated working temperatures. The material is used as a weldable steel in the fabrication of industrial boilers and steel pressurised vessels found in the oil, gas and chemical industry.
16Mo3 is a low-alloy chromium-molybdenum steel (EN 10028-2, Werkstoff 1.5415) for high-temperature industrial service. It is commonly used in pressure vessels, heat exchangers, boilers, and pipelines. It retains mechanical strength and creep resistance up to 500–600°C. Plates, sheets, and fittings are available, and it has good weldability, making it ideal for chemical, energy, and petrochemical industries.
Key Characteristics
Composition: Chromium 0.3–0.5%, molybdenum 0.2–0.3%, manganese for weldability.
High-Temperature Reliability: Creep strength and tensile properties stable at 500–600°C.
Weldability & Forming: Low-carbon design allows safe welding.
Oxidation Resistance: Reduced scaling in high-temperature steam and flue gas.
Decoding the Name
"16" ≈ 0.16% carbon
"Mo" = molybdenum for high-temperature creep and oxidation resistance
"3" = EN series identifier
Indicates low-alloy steel for boilers and pressure vessels.
Comparison
16Mo3 has chromium and molybdenum → superior high-temperature strength.
St35.8 (plain carbon steel) limited to ~300–350°C.
16Mo3 suitable for industrial boilers, superheaters, and heat exchangers.
Both are weldable, but 16Mo3 requires preheating and PWHT at thicker sections.
Common Applications
Industrial boilers and superheaters
Heat exchangers in chemical/oil industries
High-temperature pipelines
Power plant exhaust and hot steam piping
Why is 16Mo3 preferred for pressure vessels?
16Mo3 offers high tensile and yield strength, excellent creep resistance, and oxidation stability at elevated temperatures, making it reliable for pressure vessels and boilers. Its chromium-molybdenum alloy composition ensures long-term mechanical stability, safety under internal pressure, and resistance to thermal fatigue, while remaining weldable and formable for industrial fabrication.
Can 16Mo3 be welded?
16Mo3 has good weldability using TIG, MIG, or submerged arc processes. Preheating (150–250°C) and post-weld heat treatment are recommended for thick sections to avoid hydrogen-induced cracking, relieve residual stress, and maintain high-temperature mechanical properties in boilers, pipelines, and pressure vessels.
Is 16Mo3 suitable for high-pressure service?
Yes, 16Mo3 can safely handle internal pressures in high-temperature boilers, heat exchangers, and pipelines. Its combination of tensile strength, yield strength, and creep resistance ensures reliable performance. Proper fabrication and welding techniques enhance structural integrity for sustained high-pressure and high-temperature operations.
Chemical composition % of steel 16Mo3 (1.5415): EN 10028-2-2003
| C | Si | Mn | Ni | P | S | Cr | Mo | N | Cu |
| 0.12 - 0.2 | max 0.35 | 0.4 - 0.9 | max 0.3 | max 0.025 | max 0.01 | max 0.3 | 0.25 - 0.35 | max 0.012 | max 0.3 |
Chemical composition % of steel 16Mo3 (1.5415): EN 10028-2-2003
| C | Si | Mn | Ni | P | S | Cr | Mo | N | Cu |
| 0.12 - 0.2 | max 0.35 | 0.4 - 0.9 | max 0.3 | max 0.025 | max 0.01 | max 0.3 | 0.25 - 0.35 | max 0.012 | max 0.3 |
Mechanical properties of steel 16Mo3 (1.5415)
| Nominal thickness (mm): | to 60 | 60 - 100 | 100 - 150 | 150 - 250 |
| Rm - Tensile strength (MPa) (+N) | 440-590 | 430-580 | 420-570 | 410-570 |
| Nominal thickness (mm): | to 16 | 16 - 40 | 40 - 60 | 60 - 100 | 100 - 150 | 150 - 250 |
| ReH - Minimum yield strength (MPa) (+N) | 275 | 270 | 260 | 240 | 220 | 210 |
| KV - Impact energy (J) transverse, (+N) | +20° 27 |
| KV - Impact energy (J) longitud., (+QT) | +20° 50 |
| KV - Impact energy (J) transverse, (+QT) | +20° 34 |
| KV - Impact energy (J) longitud., | +20° 4 |
| A - Min. elongation at fracture (%) longitud., (+QT) | 23 |
| A - Min. elongation at fracture (%) transverse, (+N) | 20 |
1. Can 16Mo3 resist creep at high temperatures?
Yes, 16Mo3 retains strength under long-term stress at elevated temperatures due to molybdenum and chromium content. It resists microstructural changes, maintaining dimensional stability in boilers, superheaters, pipelines, and pressure vessels operating up to 500–600°C, which prevents premature deformation or failure during prolonged service.
2. Is post-weld heat treatment necessary for 16Mo3?
PWHT is recommended for thick or critical sections to relieve residual stresses and maintain creep resistance. Typical tempering ranges from 600–650°C. For thin plates or non-critical components, PWHT may be optional. Proper treatment ensures long-term reliability and prevents cracking in high-temperature pressure equipment.
3. What is the typical tensile strength of 16Mo3?
Tensile strength typically ranges from 440–590 MPa depending on thickness and manufacturing. Combined with yield strength of 220–275 MPa and elongation of 19–24%, 16Mo3 ensures safety and structural stability in superheater tubes, pipelines, and high-temperature pressure vessels under long-term thermal stress.
4. How does 16Mo3 perform at high temperatures?
16Mo3 maintains mechanical strength, creep resistance, and microstructural stability up to 500–600°C. It resists oxidation, scaling, and thermal degradation, making it ideal for boilers, superheater tubes, pipelines, and pressure vessels. Its alloying elements ensure reliable operation under prolonged thermal and mechanical stress.
5. Can 16Mo3 be used in steam environments?
Yes, 16Mo3 performs well in high-temperature steam due to its chromium and molybdenum content. It resists oxidation, scaling, and microstructural degradation, making it suitable for boilers, superheaters, heat exchangers, and pipelines exposed to continuous high-temperature steam conditions.
6. What heat treatment does 16Mo3 require?
16Mo3 is typically supplied in normalized or stress-relieved conditions. Normalizing (~890–950°C) refines the grain structure and improves mechanical properties. Post-weld tempering (600–650°C) is recommended for welded components. Heat treatment ensures creep resistance, mechanical stability, and long-term reliability in boilers, pipelines, and high-temperature pressure vessels.
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