20MnMoNi4-5 1.6311 Special Steel for Boiler and Pressure Vessel
20MnMoNi4-5 1.6311 Special Steel for Boiler and Pressure Vessel
1. 1.6311 Applications
• Boiler installations in accordance with Technical Rules TRD 101, EN 12952 etc. for temperatures up to 375 °C.
• Pressure vessel installations in accordance with the AD 2000-Merkblätter series W and HP for temperatures of – 10 °C to 375 °C.
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2.All Grades Comparison
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3.Quality Standard
EN 10250 Open steel die forgings for general engineering purposes. Alloy special steels
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4. 1.6311 Chemical Composition(%)
| C | Mn | Si | P | S | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|
| 0.17-0.23 | 1.00-1.50 | 0.40 max | 0.035 max | 0.035 max | 0.50 max | 0.40-0.80 | 0.45-0.60 |
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5.Mechanical Properties(T=20°C if not differently stated)
| Process | Diameter(mm) | Tensile Strength Rm (Mpa) | Yield Strength Rp0.2 (Mpa) | Elongation A5 (%) | Impact Value Kv (J) Room Temperature |
|---|---|---|---|---|---|
| QUENCHED AND TEMPERED | 40 max | 590-750 | 470 min | 18 min | 35 min |
| QUENCHED AND TEMPERED | 40-60 | 590-730 | 460 min | 18 min | 35 min |
| QUENCHED AND TEMPERED | 60-100 | 570-710 | 450 min | 18 min | 35 min |
| QUENCHED AND TEMPERED | 100-160 | 570-710 | 440 min | 18 min | 35 min |
| QUENCHED AND TEMPERED | 160-330 | 550 min | 390 min | 17 min | 39 min |
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6. 1.6311 HEAT TREATMENT:
- Stress Relieving: Heat to 580 – 620°C. Generally the maximum stress relieving time shall be restricted to 150 min. If it exceeds 90 min or in case of repeated heat treatment the lower range of recommended temperatures shall apply.
- Austenitizing + Quenchingg: Heat to 870 to 940 °C. After temperature achievement over the whole section cooling in water
- Tempering: Heat to 610 to 690 °C. Holding 30 min time after temperature achievement over the whole section, cooling in still air
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7.Forming properties and weldability:
1.6311 Special Steel can be hot or cold formed and can be welded and flame cut according to the general procedures. The guidelines
according to EN 1011 and VdTÜV-material data sheet 440/1 shall be observed. For the fabrication of pressure vessels in accordance with AD 2000 Merkblatt in the context of PED qualified welding consumables have to be applied.
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8.Mill′s test certificate:
EN 10204/3.1 with all relevant data reg. chem. composition, mech. properties and results of testing.
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