Reaction apparatus Material selection

Please specify the exact operating conditions and what the composition of the medium is However, under SCWO conditions at subcritical temperatures, if there is about 0.5% hydrochloric acid in the solution, the corrosion rate of Hastelloy C276 can reach 14 mm/year; the rate for Hastelloy B3 is even higher. Among nickel-based alloys, Hastelloy G30 exhibits the best corrosion resistance under these conditions, with a corrosion rate of around 5 mm/year. The corrosion rates for titanium and titanium-palladium alloys range from 0.25 mm/year to 5 mm/year. At this temperature, in 5% hydrochloric acid, tantalum has a corrosion rate of 0.003 mm/year, but in 5% sulfuric acid, its corrosion rate is as high as 0.42 mm/year. In such conditions, iridium is the best material – it does not corrode at all in media containing 5% hydrochloric acid, 1.2% hydrochloric acid, and a small amount of hydrogen peroxide. In contrast, platinum has a corrosion rate of up to 1.14 mm/year

I think Hastelloy HC-276 – although both are commonly used in seawater applications, this one has better high-temperature resistance~:lol

It is best to conduct a material tab test, right at the installation site

The high content of chromium and molybdenum in INCONEL625 alloy confers on it a high resistance to pitting and crevice corrosion; it is also resistant to corrosive agents caused by chlorides such as seawater, neutral salts, and brine. This alloy exhibits corrosion resistance against a wide range of corrosive media—from highly oxidizing environments to those with moderately reduced oxidation levels. The results of geothermal brine tests show that INCONEL alloy has extremely high resistance to geothermal water, with a corrosion resistance comparable to that of grade 2 titanium. Environmental tests simulating pipeline gas desulfurization show that INCONEL alloy possesses extremely high corrosion resistance compared to 316 alloy, with a corrosion resistance level comparable to that of Hastelloy C276 alloy. Hastelloy C276 (UNS N10276) alloy is a nickel-molybdenum-chromium-iron-tungsten alloy and is currently the alloy with the highest corrosion resistance. A high molybdenum content endows the alloy with resistance to local corrosion, such as pitting. The low carbon content minimizes the precipitation of carbides during welding, thereby maintaining the property of resisting intergranular corrosion in the heat-affected areas of the weld joint. Although the Hastelloy C276 alloy eventually becomes brittle and develops precipitates under high temperatures, it still possesses good high-temperature strength as well as moderate oxidation resistance. The Hastelloy C276 alloy has been in use for many years in construction projects related to boilers and pressure valves as specified by the American Society of Mechanical Engineers standards.

Hasn’t such a special operating condition been used before? Try to find relevant operating conditions as a reference. What kind of acid is it? How many halogen elements are contained?