Hangbo Alloy Group
Shanghai · Est. 2012
N06205 technical guide: nominal chemical composition, mechanical and physical properties, corrosion resistance, welding, product forms and ASTM standards...
Hastelloy D-205 (UNS N06205) is a silicon-bearing nickel-chromium-molybdenum alloy. Silicon-bearing for hot H2SO4 + abrasion. Hard, acid-resistant surface. This guide covers its nominal chemical composition, typical mechanical and physical properties, corrosion behaviour, welding, common applications, available product forms and the ASTM standards that apply — everything a specifier needs to evaluate Hastelloy D-205 for a project.
Hastelloy D-205 belongs to the silicon-bearing nickel-chromium-molybdenum alloy class of materials. It is silicon-bearing for hot h2so4 + abrasion. It is hard, acid-resistant surface. It is pump/valve parts in abrasive acids.
Nominal (wt%) composition of Hastelloy D-205 (UNS N06205):
| Element | Composition (wt%) |
|---|---|
| Nickel (Ni) | Balance |
| Chromium (Cr) | 15.0 – 17.0 |
| Molybdenum (Mo) | 15.0 – 17.0 |
| Copper (Cu) | 1.0 – 2.0 |
| Silicon (Si) | 3.5 – 4.5 |
| Iron (Fe) | ≤ 3.0 |
| Carbon (C) | ≤ 0.05 |
| Manganese (Mn) | 1.0 – 2.0 |
| Phosphorus (P) | ≤ 0.040 |
| Sulphur (S) | ≤ 0.030 |
Typical physical properties:
| Property | Value |
|---|---|
| Density | 8.50 g/cm³ |
| Melting Range | 1300 – 1360 °C |
| Thermal Expansion (20–1000 °C) | 12.5 µm/m·K |
| Thermal Conductivity (100 °C) | 12.0 W/m·K |
| Electrical Resistivity | 1.20 µΩ·m |
| Modulus of Elasticity | 200 GPa |
Typical room-temperature mechanical properties (annealed / specified condition unless noted):
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 760 MPa (110 ksi) |
| Yield Strength, 0.2% (Rp0.2) | 380 MPa (55 ksi) |
| Elongation in 50 mm | 35% |
| Hardness (Rockwell B) | 90 – 100 HRB |
| Property | Value |
|---|---|
| Service temperature | Up to ≈ 500 °C |
| Service note | Resists hot H2SO4 + abrasion |
D-205 is a silicon-bearing Ni-Cr-Mo alloy that resists both hot concentrated sulphuric acid and abrasive/erosive conditions – the original Hastelloy D niche, updated with chromium and molybdenum for broader corrosion resistance. The silicon provides a hard, acid-resistant surface.
Welded with matching fillers under a qualified procedure; the high silicon requires controlled heat input. Often used for pump/valve parts in abrasive acid slurries.
The grade is supplied to the following common specifications:
| Standard | Product Form / Scope |
|---|---|
| ASTM B333 | Plate, sheet & strip |
| ASTM B335 | Bar |
| ASTM B366 | Fittings |
| ASTM A494 | Castings (reference) |
D-205 (UNS N06205) is a silicon-bearing Ni-Cr-Mo alloy that resists hot concentrated sulphuric acid and abrasive/erosive conditions – the classic Hastelloy D niche, updated with chromium and molybdenum for broader corrosion resistance. Silicon gives a hard, acid-resistant surface.
Annealed: ≈ 760 MPa tensile, ≈ 380 MPa yield, 35 % elongation, 90–100 HRB.
Hot concentrated sulphuric acid handling, pumps/valves/fittings in abrasive acid slurries, pickling and concentrating equipment and erosion-corrosion service.
Yes, with matching fillers under a qualified procedure; the high silicon needs controlled heat input. Often applied to pump/valve parts.
C-276 is the general chloride/pitting specialist; D-205 is specialised for hot concentrated sulphuric acid plus abrasion, thanks to its silicon content.
Plate/sheet/strip ASTM B333, bar ASTM B335, fittings ASTM B366, with casting references under ASTM A494.
As a dedicated nickel alloy manufacturer serving chemical processing, oil & gas sectors, Hangbo Alloy Group supplies the grades discussed here across all standard product forms with full ASTM/ASME documentation and EN 10204 3.1 certification. Our material is specified for applications where corrosion resistance, high-temperature strength, and traceable quality are non-negotiable. See our production & testing facilities for more on how every heat is verified.