Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Durehete Chemical Composition — Alloy T41 / T31 / T22 (EN 10269)
The Durehete family chemistry is tightly controlled within the EN 10269 envelope. Durehete 1055 (Alloy T41 / 20CrMoVTiB4-10 / 1.7729) carries the titanium and boron microalloying that distinguishes it from the plain Cr-Mo-V grades 950 and 900.
Durehete 1055 (Alloy T41 / 1.7729 / 20CrMoVTiB4-10)
| Element | Range (wt %) |
|---|---|
| Carbon (C) | 0.17 to 0.23 |
| Silicon (Si), max | 0.40 |
| Manganese (Mn) | 0.35 to 0.75 |
| Phosphorus (P), max | 0.025 |
| Sulphur (S), max | 0.025 |
| Chromium (Cr) | 0.90 to 1.20 |
| Molybdenum (Mo) | 0.90 to 1.10 |
| Vanadium (V) | 0.60 to 0.80 |
| Titanium (Ti) | 0.07 to 0.15 |
| Boron (B), max | 0.02 |
Durehete 950 (Alloy T31 / 1.7711 / 40CrMoV4-6)
| Element | Range (wt %) |
|---|---|
| Carbon (C) | 0.36 to 0.44 |
| Silicon (Si), max | 0.40 |
| Manganese (Mn) | 0.40 to 0.70 |
| Phosphorus (P), max | 0.025 |
| Sulphur (S), max | 0.025 |
| Chromium (Cr) | 0.90 to 1.20 |
| Molybdenum (Mo) | 0.50 to 0.70 |
| Vanadium (V) | 0.25 to 0.35 |
Durehete 900 (Alloy T22 / 42CrMoV5-6)
| Element | Range (wt %) |
|---|---|
| Carbon (C) | 0.38 to 0.46 |
| Silicon (Si), max | 0.40 |
| Manganese (Mn) | 0.50 to 0.80 |
| Phosphorus (P), max | 0.025 |
| Sulphur (S), max | 0.025 |
| Chromium (Cr) | 1.20 to 1.50 |
| Molybdenum (Mo) | 0.50 to 0.65 |
| Vanadium (V) | 0.20 to 0.35 |
Why Ti+B Microalloying Matters
The titanium and boron additions in Durehete 1055 are the procurement differentiator from the plain Cr-Mo-V grades. Titanium ties up free nitrogen as TiN dispersoids that pin grain boundaries; boron segregates to grain boundaries and slows M23C6 carbide coarsening at long-duration high-temperature exposure. The combined effect is a 25-50°C lift in usable service temperature versus 950 and 900 at the same 100,000-hour design stress.
Frequently Asked Questions
What is the difference between Durehete 1055 and 950 chemistry?
1055 (Alloy T41) is lower carbon (0.17-0.23 vs 0.36-0.44), higher Mo (0.90-1.10 vs 0.50-0.70), higher V (0.60-0.80 vs 0.25-0.35), plus the Ti+B microalloying. The combined effect lifts the service temperature ceiling from 540 to 565 degrees Celsius.
Is Durehete 900 chemically the same as Durehete 950?
No. Durehete 900 (42CrMoV5-6) has higher chromium (1.20-1.50 vs 0.90-1.20) but lower molybdenum (0.50-0.65 vs 0.50-0.70). Service ceiling is 500 degrees Celsius.
What is the closest ASTM equivalent for Durehete 950 chemistry?
ASTM A193 Grade B16. Chemistry envelopes overlap; both specifications cover the Cr-Mo-V bolting family at 540 degrees Celsius continuous service.
Are inclusion limits specified?
EN 10269 references EN 10247 for non-metallic inclusion rating. TorqBolt heat lineage maintains low-inclusion practice with secondary refining (vacuum degassing or ladle refining) on the EN 10269 heat lots.
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