General Properties
Alloy 316/316L (UNS S31600/S31603) is a chromium-nickelmolybdenum austenitic stainless steel developed to provide improved corrosion resistance to Alloy 304/304L in moderately corrosive environments. It is often utilized in process streams containing chlorides or halides. The addition of molybdenum improves general corrosion and chloride pitting resistance. It also provides higher creep, stress-to-rupture and tensile strength at elevated temperatures.
It is common practice for 316L to be dual certified as 316 and 316L. The low carbon chemistry of 316L combined with an addition of nitrogen enables 316L to meet the mechanical properties of 316.
Alloy 316/316L resists atmospheric corrosion, as well as, moderately oxidizing and reducing environments. It also resists corrosion in polluted marine atmospheres. The alloy has excellent resistance to intergranular corrosion in the as-welded condition. Alloy 316/316L has excellent strength and toughness at cryogenic temperatures.
Alloy 316/316L is non-magnetic in the annealed condition, but can become slightly magnetic as a result of cold working or welding. It can be easily welded and processed by standard shop fabrication practices.
Chemical Analysis
Weight % (all values are maximum unless a range is otherwise indicated)
| Element | 316 | 316L |
|---|---|---|
| Chromium | 16.0 min.-18.0 max. | 16.0 min.-18.0 max. |
| Nickel | 10.0 min.-14.0 max. | 10.0 min.-14.0 max. |
| Molybdenum | 2.00 min.-3.00 max. | 2.00 min.-3.00 max. |
| Carbon | 0.08 | 0.030 |
| Manganese | 2.00 | 2.00 |
| Phosphorus | 0.045 | 0.045 |
| Sulfer | 0.03 | 0.03 |
| Silicon | 0.75 | 0.75 |
| Nitrogen | 0.1 | 0.1 |
| Iron | Balance | Balance |
Lowest Temperature (°F) at Which the Corrosion Rate Exceeds 5mpy
| CORROSION ENVIRONMENT | Type 316L | Type 304 | 2205 (UNS S32205) | 2507 |
|---|---|---|---|---|
| 0.2% Hydrochloric Acid | >Boiling | >Boiling | >Boiling | >Boiling |
| 1% Hydrochloric Acid | 86 | 86p | 185 | >Boiling |
| 10% Sulfuric Acid | 122 | — | 140 | 167 |
| 60% Sulfuric Acid | <54 | — | <59 | <57 |
| 96% Sulfuric Acid | 113 | — | 77 | 86 |
| 85% Phosphoric Acid | 203 | 176 | 194 | 203 |
| 10% Nitric Acid | >Boiling | >Boiling | >Boiling | >Boiling |
| 65% Niitric Acid | 212 | 212 | 221 | 230 |
| 80% Acetic Acid | >Boiling | 212p | >Boiling | >Boiling |
| 50% Formic Acid | 104 | ≤50 | 194 | 194 |
| 50% Sodium Hydroxide | 194 | 185 | 194 | 230 |
83% Phosphoric Acid + | 149 | 113 | 122 | 140 |
| 60% Nitric Acid + 2% Hydrocloric Acid | >140 | >140 | >140 | >140 |
| 50% Acetic Acid + 50% Acetic Anhydride | 248 | >Boiling | 212 | 230 |
| 1% Hydrochloric Acid + 0.3% Ferric Chloride | 77p | 68p | 113ps | 203ps |
| 10% Sulfuric Acid + 2000ppm Cl- + N2 | 77 | — | 95 | 122 |
| 10% Sulfuric Acid + 2000ppm Cl- + SO2 | <<59p | — | <59 | 104 |
| WPA1, High Cl- Content | ≤50 | <<50 | 113 | 203 |
| WPA2, High F- Content | ≤50 | <<50 | 140 | 167 |
ps = pitting can occur
ps = pitting/crevice corrosion can occur
