Description
Most of the existing 316L on the market are produced according to American standards. In consideration of cost, steel mills generally limit the Ni content of products to the lower limit as far as possible. The American standard stipulates that the Ni content of 316L is 10 ~ 14%, and the Japanese standard stipulates that the Ni content of 316L is 12 ~ 15%. According to the minimum standard, there is a difference of 2% in Ni content between American Standard and Japanese standard, which is reflected in the price. Therefore, customers still need to see whether the product refers to ASTM or JIS standard when purchasing 316L products.
The Mo content of 316L makes the steel have excellent pitting corrosion resistance and can be safely applied to the environment containing halogen ions such as Cl -. Since 316L is mainly used for its chemical properties, steel mills have slightly lower requirements for surface inspection of 316L (compared with 304), and customers with higher surface requirements should strengthen surface inspection. The two most commonly used stainless steels 304316 (or 1.4308,1.4408 corresponding to German / European standards), the main difference between 316 and 304 in chemical composition is that 316 contains Mo, and it is generally recognized that 316 has better corrosion resistance and is more corrosion resistant than 304 in high temperature environment. Therefore, in high temperature environment, engineers generally choose 316 parts. But the so-called thing is not absolute. In the concentrated sulfuric acid environment, do not use 316 at any high temperature. Otherwise, it will be big. People who study mechanics have all studied threads. I still remember a black solid lubricant that needs to be applied to prevent threads from biting at high temperature: molybdenum disulfide (MoS2), from which two conclusions can be drawn: first, Mo is indeed a high-temperature resistant material (do you know what crucible gold is melted in? Molybdenum crucible!). 2: Molybdenum easily reacts with high valence sulfur ions to form sulfide. Therefore, no stainless steel is super invincible and corrosion resistant. In the final analysis, stainless steel is a steel with more impurities (but these impurities are more corrosion-resistant than steel). If it is steel, it can react with other substances.