Is 321 stainless steel plate better or 316L stainless steel plate better?

321 stainless steel plate is based on 304 stainless steel by adding titanium element to prevent grain boundary corrosion. It belongs to austenitic stainless steel, and its national label is 06Cr18Ni11Ti. Its characteristic is that the chemical composition contains titanium element, which makes it have better resistance to intergranular corrosion and high temperature strength, and is suitable for use in the high temperature state of 430℃-900℃. Its uses are aircraft exhaust pipes, boilers, heat exchangers. 321 stainless steel has a series of characteristics such as excellent corrosion resistance, formability and toughness in a wide temperature range, so it has been widely used in heavy industry, light industry, daily necessities industry and architectural decoration and other industries, but it is used in different environments. It is very important to choose different stainless steel varieties.

316L stainless steel plate is the second most widely used austenitic stainless steel after 304 stainless steel, and its national grade is 022Cr17Ni12Mo2. It is characterized by adding 2-3% molybdenum element, with excellent resistance to pitting corrosion, acid and alkali and high temperature. Most of the existing 316L on the market are produced according to American Standard. For cost reasons, steel mills generally try to lower the Ni content of their products to the lower limit. The American standard stipulates that the Ni content of 316L is 10-14%, while the Japanese standard stipulates that the Ni content of 316L is 12-15%. According to the minimum standard, there is a 2% difference in Ni content between the American standard and the Japanese standard, which is quite huge in terms of price. Therefore, customers still need to see clearly when purchasing 316L products, whether the products refer to ASTM or JIS standards.

The Mo content of 316L makes this steel with excellent resistance to pitting corrosion and can be safely used in environments containing Cl- and other halogen ions. Since 316L is mainly used for its chemical properties, steel mills have slightly lower requirements for surface inspection of 316L (compared to 304), and customers with higher surface requirements should strengthen surface inspection.

Closer to home, is the 321 better or the 316L better? The editor thinks that 316L stainless steel plate has better performance, and 321 stainless steel only has titanium. Of course, the price is also different, mainly depends on the demand and application scenarios.