What Is The Difference Between 904L Stainless Steel And 316L Stainless Steel?
Leave a message
What is the difference between 904L stainless steel and 316L stainless steel?
The difference between 904L stainless steel and 316L stainless steel:
1. Different copper contents: 904L stainless steel contains a certain amount of copper, but 316L stainless steel does not contain copper.
2. Different corrosion resistance and wear resistance: 904L stainless steel has stronger corrosion resistance and wear resistance than 316L stainless steel.
3. Different weights: 904L stainless steel contains higher amounts of molybdenum, nickel, and copper than 316L stainless steel, and the specific gravity of these three metals is greater than that of iron. Therefore, in terms of weight, 904L stainless steel of the same volume will be much heavier than 316L stainless steel.
4. They have different uses:
Uses of 904l stainless steel: widely used in petroleum and petrochemical equipment, such as reactors in petrochemical equipment; sulfuric acid storage and transportation equipment, such as heat exchangers; power plant flue gas desulfurization equipment, the main parts used are: absorption tower Tower body, flue, door panel, internal parts, sprinkler system, etc.
Uses of 316l stainless steel: 316l stainless steel is used in seawater treatment equipment, seawater heat exchangers, paper industry equipment, sulfuric acid and nitric acid equipment, sulfuric acid, pharmaceutical industry and other chemical equipment, pressure vessels, and food equipment.
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, it will cause serious problems.
Anyone who has studied mechanics has learned about threads. They still remember that in order to prevent threads from seizing at high temperatures, a dark solid lubricant needs to be applied: molybdenum disulfide (MoS2).
Two conclusions can be drawn from this:
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.
