The two most commonly used stainless steels are 304 and 316 (or 1.4308 and 1.4408 corresponding to the German/European standards). The main difference in chemical composition between 316 and 304 is that 316 contains Mo, and it is generally recognized that 316 has better corrosion resistance. , more corrosion resistant than 304 in high temperature environments. Therefore, in high temperature environments, engineers generally choose parts made of 316 material. But as the saying goes, there are no absolutes. In a concentrated sulfuric acid environment, no matter how high the temperature is, never use 316! Otherwise, this matter would be a big deal.

Anyone who studies mechanics has learned about threads. Remember that in order to prevent threads from seizing at high temperatures, you need to apply a dark solid lubricant: molybdenum disulfide (MoS2). From it, two points can be drawn. The conclusion is not:

[1] Mo is indeed a substance that can withstand high temperatures (do you know what crucible is used to melt gold? Molybdenum crucible!).

[2]: Molybdenum can easily react with high-valent sulfide ions to form sulfide. Therefore, no stainless steel is super corrosion-resistant. After all, stainless steel is just a piece of steel with more impurities (but these impurities are more corrosion-resistant than steel^^). Steel can react with other substances.