Alloy 825, often referred to as Incoloy 825 (where Incoloy is a trademark of Special Metals Corp), is a nickel-iron-chromium alloy with additions of molybdenum, copper and titanium (NiCr21Mo), supplied in the hot worked and annealed condition. The alloy achieves good mechanical properties from cryogenic to medium-high temperatures (5400C) and can be significantly strengthened if required through cold working.
The high nickel content ensures resistance to stress corrosion cracking, combined with molybdenum and copper to strongly resist reducing environments such as sulphuric and phosphoric acids. Chromium aids in the resistance to oxidising environments such as nitric acid and titanium inhibits intergranular corrosion, and overall resistance to pitting and crevice corrosion.
|0.2% Proof Stress||241 N/mm2||35 ksi|
|Tensile Strength||518 N/mm2||75 ksi|
|Elongation, 5.65√S0 and 4D||30%|
|Reduction of Area|
|Hardness (Brinell)||331 max.|
|Magnetic Permeability (20°C)||1.005|
|Curie Temperature (°C)||-196|
|Young’s Modulus (N/mm2)||196|
|Specific Heat, 20°C (J/(g.K))||440|
|Specific Electrical Resistance, 20°C (Ω-m)||0.00113|
|Thermal conductivity, 20°C (W/(m.K))||10.8|
|Mean coefficient of thermal expansion, 20-100°C (/K)||14.1 x 10-6|