2.4610 is a low-carbon austenitic nickel–chromium–molybdenum alloy — the most microstructurally stable of the widely used Ni-Cr-Mo materials. This datasheet presents the material within the European (DIN / EN / Werkstoff-Nummer / VdTÜV) standard system.
Its defining attribute is exceptional thermal/structural stability: controlled low carbon, silicon and iron, the absence of tungsten, and a small titanium addition together suppress the nucleation and growth of deleterious second-phase precipitates (such as M₆C carbides and sigma/mu phases) in the grain boundaries of the weld heat-affected zone. As a result the alloy can be welded without fear of sensitisation, and it retains structural stability and ductility even after prolonged exposure in the 650–1040 °C range.
With its high chromium and molybdenum contents it withstands both oxidising and non-oxidising acids — in particular hydrochloric, sulphuric, formic and acetic acids and acid blends — and resists pitting and crevice attack in chloride and other halide media. Like other nickel alloys it is ductile, easy to form and weld, and possesses outstanding resistance to chloride stress-corrosion cracking. It is used widely in chemical-process equipment, and is listed in ISO 15156-3 / ISO 15156 for sour service.
Values per manufacturer (VDM / Haynes) data, solution-annealed condition.
| Property | Value | Unit |
|---|---|---|
| Density | 8.64 | g/cm³ |
| Melting range | 1350–1380 | °C |
| Young's modulus (20 °C) | 211 | GPa |
| Thermal conductivity (20 °C) | 10.1 | W/m·K |
| Specific heat capacity (20 °C) | 406 | J/kg·K |
| Electrical resistivity (20 °C) | 1.25 | µΩ·m |
| Coefficient of thermal expansion (20–100 °C) | 10.8 | µm/m·°C |
| Maximum structural-stability temperature | ~1040 | °C |
| Structure | Austenitic (FCC) | — |
Composition per VdTÜV-Wbl 505 / DIN 17744 (W.Nr. 2.4610, NiMo16Cr16Ti).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Nickel | Ni | Balance | — | Base; SCC resistance |
| Chromium | Cr | 14.0 | 17.0 | Oxidising-media resistance |
| Molybdenum | Mo | 14.0 | 17.0 | Reducing-acid + pitting/crevice resistance |
| Iron | Fe | — | 3.0 | Residual |
| Cobalt | Co | — | 2.0 | Residual |
| Titanium | Ti | — | 0.7 | Stabiliser (anti-sensitization) |
| Manganese | Mn | — | 1.0 | Deoxidiser |
| Carbon | C | — | 0.009 | Ultra-low (thermal stability) |
| Silicon | Si | — | 0.05 | Very low (thermal stability) |
| Phosphorus | P | — | 0.02 | Residual impurity |
| Sulphur | S | — | 0.01 | Residual impurity |
Nominal: Ni-16Cr-16Mo-Ti. The very low carbon (≤0.009%) and silicon (≤0.05%) suppress grain-boundary precipitation between 650-1040 °C, giving improved thermal stability and intergranular-corrosion resistance; titanium stabilises the alloy.
Solution-annealed condition (20 °C), per VdTÜV-Wbl 505 for W.Nr. 2.4610.
| Property | Value | Unit |
|---|---|---|
| Tensile strength (Rm) | 700–900 | MPa |
| 0.2% proof strength (Rp0.2) | ≥300 | MPa |
| Elongation at fracture (A5.65) | ≥40 | % |
| Modulus of elasticity | 211 | GPa |
Values per EN/DIN; confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| Hydrochloric acid | Excellent | High Mo content |
| Sulphuric acid | Excellent | Both oxidising + reducing conditions |
| Formic / acetic acid | Excellent | Organic-acid resistance |
| Acid blends (e.g. HCl + HNO₃) | Outstanding | Balanced Cr/Mo; resists contaminated mineral acids |
| Pitting / crevice (halides) | Excellent | High Mo; chloride/halide media |
| Chloride SCC | Outstanding | Routinely specified where stainless steels fail |
| Weld HAZ / sensitisation | Outstanding | Most stable Ni-Cr-Mo; no σ/μ/M₆C in HAZ |
| Thermal stability (650–1040 °C) | Outstanding | No detrimental intermetallic phases |
A solid-solution, low-carbon Ni-Cr-Mo alloy; not age-hardenable. Heat treatment is solution annealing only.
Solution Anneal Temperature: ~1065 °C (1950 °F), followed by rapid cooling (water quench) Purpose: dissolves secondary phases, restores maximum corrosion resistance and ductility.
C-4's defining advantage is that, owing to its exceptional microstructural stability, it resists sensitisation even after exposure in the 650–1040 °C range — so welded assemblies generally do not require a post-weld solution anneal for corrosion service.
Outstanding weldability — the key advantage of C-4. Its microstructural stability means it can be welded without fear of HAZ sensitisation (no second-phase grain-boundary precipitation), so it is suitable for as-welded service in aggressive media.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Excellent | EN ISO 18274 matching Ni-Cr-Mo filler (2.4610 type) |
| GMAW / MIG | Excellent | EN ISO 18274 matching Ni-Cr-Mo filler (2.4610 type) |
| SMAW / stick | Good | EN ISO 14172 matching electrode |
Keep the joint clean and oxide-free. Post-weld heat treatment is generally not required for corrosion service, owing to the alloy's stability.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Work hardening | Moderate-to-high; rigid setup, sharp tooling, positive rake |
| Cutting | Low speed, sufficient feed/depth to cut below work-hardened layer |
| Coolant | Ample flood coolant |
| Preferred condition | Solution-annealed |
Forming Processes
| Process | Notes |
|---|---|
| Hot forming | ~954–1107 °C; solution-anneal after hot forming |
| Cold forming | Readily cold-formed; solution-anneal after heavy reductions |
| All standard techniques | Cold and hot formable |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Chemical processing | Reactors, heat exchangers, columns, piping | Mixed-acid + thermal stability + as-welded service |
| Hydrochloric / sulphuric acid | Process vessels and piping | Strong-acid resistance |
| Halide / chloride media | Equipment exposed to chlorides | Pitting/crevice + SCC resistance |
| Welded fabrications | Structures needing as-welded corrosion resistance | No HAZ sensitisation |
| High-temperature corrosion | Components in 650–1040 °C corrosive service | Thermal stability |
| Product Form | DIN Standard | VdTÜV | Other |
|---|---|---|---|
| Rod and bar | DIN 17752 | VdTÜV 424 | AFNOR AIR 9161 |
| Plate, sheet and strip | DIN 17750 | VdTÜV 424 | — |
| Seamless tube | DIN 17751 | VdTÜV 424 | — |
| Composition | DIN 17744 | — | — |
| Wire | DIN 17753 | — | — |
| Welding consumables | EN ISO 18274 matching Ni-Cr-Mo filler | — | — |
W.Nr. 2.4610 (NiMo16Cr16Ti); VdTÜV-Werkstoffblatt 424; listed in ISO 15156-3 / ISO 15156.
| W.Nr. | Ni % | Cr % | Mo % | Other | Best Used For |
|---|---|---|---|---|---|
| 2.4610 | bal | 14.5–17.5 | 14–17 | Ti, no W | Most thermally stable; as-welded service |
| 2.4819 | bal | 14.5–16.5 | 15–17 | W 3–4.5 | Broad corrosion workhorse; as-welded |
| 2.4602 | bal | 20–22.5 | 12.5–14.5 | W 2.5–3.5 | Best pitting/crevice; oxidising media |
| 2.4675 | bal | 22–24 | 15–17 | Cu 1.6 | Most versatile; Cu for reducing acids |
| 2.4600 | bal | 1–3 | 27–32 | C ≤0.01 | Reducing acids only (Ni-Mo, near-zero Cr) |




