Alloy 218 is the best non-galling stainless steel. It is silicon/manganese alloyed austenitic stainless steel with double yield strength of AISI 304 material. The increased silicon and manganese level inhibit wear, galling and fretting and makes the alloy fit for temperatures up to 1000°C.
| Zeon Grade | Alloy Name | UNS | Trademarks |
|---|---|---|---|
| Zeon218 | Alloy 218 | UNS S21800 | Nitronic 60 |
| Element | Content (%) |
|---|---|
| Chromium, Cr | 16-18 |
| Nickel, Ni | 8-9 |
| Manganese, Mn | 7-9 |
| Silicon, Si | 3.5-4.5 |
| Carbon, C | 0.1 max |
| Nitrogen, N | 0.08-0.18 |
| Phosphorus, P | 0.04 max |
| Sulfur, S | 0.03 max |
| Iron, Fe | Remainder |
| Properties | Metric | Imperial |
|---|---|---|
| Density | 7.7 g/cm³ | 0.28 lb/in³ |
| Properties | Metric | Imperial |
|---|---|---|
| Tensile strength | 724 MPa | 105 ksi |
| Yield strength | 379 MPa | 55 ksi |
| Poisson's ratio | 0.298 | 0.298 |
| Elongation | 35% | 35% |
| Reduction of area | 55% | 55% |
| Corrosion Resistance Properties of Alloy 218 |
|---|
| General corrosion resistance of Alloy 218 is between AISI 304 and 316. It offers better chloride pitting resistance, stress corrosion cracking resistance and crevice corrosion resistance than AISI 316L in laboratory conditions. |
| Machinability | Positive feeds, slow speeds, and resulphurized lubricants are suitable for machining super alloy NITRONIC60. |
|---|---|
| Forming | Super alloy NITRONIC60 can be formed using standard techniques. |
| Welding: | Super alloy NITRONIC60 can be welded using common welding techniques such as gas metal arc welding, gas tungsten arc welding, and submerged arc |
| Forging | Super alloy NITRONIC60 is forged by heating at 1094°C (2000°F) followed by soaking. |
| Annealing | Super alloy NITRONIC60 is annealed by soaking at 1038 to 1122°C (1900 to 2050°F) followed by quenching in water or air. |
| Hardening | Super alloy NITRONIC60 can be hardened only by cold working. |
| Applications | Internal combustion valves and seats, Pump components, Bridge spacers, Pin and roller bearings, High wear applications |