DESCRIPTION
ХН78Т – a special heat-resistant alloy based on nickel and chromium is designed for continuous operation at temperatures up to 1100 °C. It has such properties as excellent resistance to oxidizing environments at temperatures up to 1100 °C, good mechanical properties at temperatures up to 1000 °C, resistance to the formation of oxide on the surface at temperatures up to 1000 °C, good metallurgical stability. It is melted in open electric furnaces and by using different types of melting.
Main application ХН78Т – unloaded or low-loaded details operating in corrosive gas environments with temperatures of 550-1100 °C (II group); loaded details with 100-1000 hours of work at temperatures up to 1000 °C (III group). For example: flame tube, combustion chamber, flues, covers for thermocouples, etc.
CHEMICAL COMPOSITION
| Nom. composition | С | Si | Mn | S | P | Сr | Ni | Fe | Ti | Al |
| Min | – | – | – | – | – | 19.00 | Rest | – | 0.15 | – |
| Max | 0.12 | 0.80 | 0.70 | 0.010 | 0.015 | 22.00 | 1.00 | 0.35 | 0.15 |
PHYSICAL PROPERTIES
| Temperature | 20°С | 100°С | 200°С | 300°С | 400°С | 500°С | 600°С | 700°С | 800°С | 900°С |
| Coefficient of elasticity, 10-5 MPа | 2.24 | 2.19 | 2.13 | 2.06 | 2.00 | 1.93 | 1.84 | – | – | – |
| Coefficient of linear expansion, ? x 10-6/К | – | 12.20 | 13.00 | 13.40 | 13.80 | 14.10 | 14.70 | 15.40 | 15.50 | – |
| Thermal conductivity, W/mK | – | 14.60 | 16.70 | 18.50 | 20.60 | 22.70 | 24.80 | 26.80 | 28.90 | – |
| Resistance, ? mm2/m | 1.09 | 1.099 | 1.108 | 1.117 | 1.127 | 1.153 | 1.135 | 1.126 | 1.123 | – |
MECHANICAL PROPERTIES
| Tensile strength, sв | Yield strength, sT | Elongation, d5 | Contraction ratio, y | Hardness |
| N/mm2 (kgf/mm2) | N/mm2 (kgf/mm2) | % | % | НВ |
| > 700 (71) | >300 (40) | >30 | >50 | <230.00 |
PRODUCT RANGE
| Finish | Diameter, mm | Standard (chemical composition) | Standard (product range) |
| Hot rolled | 8.00 – 75.00 | ГОСТ 5632-72 | ГОСТ 2590-2006; ГОСТ 2590-88; ГОСТ 5949-75; ГОСТ 2591-88; ТУ 14-1-1671-76 |
| Forgings | 75.00 – 350.00 | ГОСТ 5632-72 | ГОСТ 25054-81; ТУ 14-1-1530-75; ТУ 14-1-1531-75; ТУ1 4-1-2902-80 |
ANALOGUES
| W.N | EN | International name | UNS |
| 2.4951 | NiCr20Ti | Alloy 75 | N06075 |