Thread Content
Considering the location and morphological characteristics of S-H2S-RSH corrosion (high-temperature sulfur corrosion) as described earlier, the main factors that influence it are as follows: Temperature. An increase in temperature accelerates the chemical reactions between sulfur, hydrogen sulfide, thiol compounds and metals, while also promoting the thermal decomposition of inert sulfides in crude oil. Corrosion is mild below 240°C; the corrosion rate increases significantly in the range of 350–400°C, reaching a peak around 425°C. After 480°C, the sulfides are essentially completely decomposed, and corrosion slows down instead. The composition of medium sulfides: The corrosivity of oils is not directly proportional to the total sulfur content; rather, it depends on the amount of active sulfides (elemental sulfur, H₂S, thiol RSH), which can react directly with metals ； Inactive sulfides (thiethers, thiophenes, etc.) do not corrode metals directly, but they can indirectly accelerate corrosion by decomposing into active sulfides at high temperatures. Medium flow rate and flow regime: High flow rates, turbulent or vortex-like conditions can erode the FeS protective layer formed on the metal surface, keeping the fresh metal surface exposed and thereby significantly increasing the corrosion rate. Corrosion in areas such as pipe elbows and transfer lines is notably higher than in regions with lower flow rates.