Alloy 825/UNS N08825 is a nickel-iron-chromium alloy with added elements such as molybdenum, copper and titanium, which has excellent corrosion resistance and high temperature performance. Its chemical composition combination makes it perform well in both oxidizing and reducing environments, especially resistant to sulfuric acid, phosphoric acid and seawater corrosion. The carbon content of the alloy is controlled below 0.05%, and the stabilization treatment of titanium effectively inhibits intergranular corrosion caused by the precipitation of chromium carbides.

Alloy 825/UNS N08825 is widely used in the chemical, petroleum, marine and energy fields. Typical applications include heat exchangers, reactors, piping systems and components in acidic gas environments. It maintains good strength in high temperature environments (up to 540°C) and resists stress corrosion cracking (SCC) and pitting. In terms of manufacturing process, it can be formed by hot and cold processing, welding (TIG or MIG welding is recommended) and heat treatment (such as annealing to 930-980°C and rapid cooling). Compared with similar alloys such as Hastelloy, it has lower cost but slightly inferior halide resistance; compared with 316 stainless steel, it has significantly longer life in harsh environments. This alloy complies with standards such as ASTM B424/ASME SB424 and is the preferred material for balancing cost and performance.