Alloy 625 A nickel-chromium-molybdenum alloy, with an addition of niobium that acts with the Molybdenum to stiffen the alloy’s matrix which provides high strength without a strengthening heat Treatment. The alloy resists a wide range of severely corrosive environments and is especially resistant to pitting and crevice corrosion. Used in chemical processing, aerospace and marine engineering, pollution- Control equipment and nuclear reactors.
| Weight % | Ni | Cr | Fe | Mo | Nb+Ta | C | Mn | Si | P | S | Al | Ti | Co |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Minimum | 58.0 | 20.0 | — | 8.0 | 3.15 | — | — | — | — | — | — | — | — |
| Maximum | — | 23.0 | 5.0 | 10.0 | 4.15 | 0.10 | 0.50 | 0.50 | 0.015 | 0.015 | 0.40 | 0.40 | 1.0 |
| Characteristics | English | Metric | |
|---|---|---|---|
| Nominal density | 20°C / 68°F | 0.305 lbs/in3 | 8.44 g/cm3 |
| Melting range | 2350-2460 °F | 1290-1350 °C | |
| Specific heat | 21°C / 70°F | 0.098 BTU/lb – °F | 410 J/KG- °K |
| Average coefficient of
thermal expansion |
204°C / 400°F | 7.3 micro in/in- °F | 13.1 micro m/m- °K |
| 427°C / 800°F | 7.6 micro in/in- °F | 13.7 micro m/m- °K | |
| 649°C /1200°F | 8.2 micro in/in- °F | 14.8 micro m/m- °K | |
| 760°C /1400°F | 8.5 micro in/in- °F | 15.3 micro m/m- °K | |
| 871°C /1600°F | 8.8 micro in/in- °F | 15.8 micro m/m- °K | |
| Thermal conductivity | 204°C / 400°F | 7.23 BTU/ft- hr – °F | 12.5 W/m – °K |
| 427°C / 800°F | 9.08 BTU/ft- hr – °F | 15.7 W/m – °K | |
| 649°C /1200°F | 11.00 BTU/ft- hr – °F | 19.0 W/m – °K | |
| 760°C /1400°F | 12.00 BTU/ft- hr – °F | 20.8 W/m – °K | |
| 871°C /1600°F | 13.20 BTU/ft- hr – °F | 22.8 W/m – °K | |
| Electrical resistivity | 204°C / 400°F | 1340 nΩ ∙ m | |
| 427°C / 800°F | 1360 nΩ ∙ m | ||
| 649°C /1200°F | 1380 nΩ ∙ m | ||
| 760°C /1400°F | 1370 nΩ ∙ m | ||
| 871°C /1600°F | 1360 nΩ ∙ m | ||
| Form | Tensile | Hardness | ||||
|---|---|---|---|---|---|---|
| Ultimate | Yield | Elongation in
50 mm (2 in.) |
Brinell | |||
| KSI | MPa | KSI | MPa | % | ||
| Annealed | 120-150 | 827-1034 | 60-90 | 414-621 | 55-30 | 145-240 |