316 Stainless Steel Pipe

316L is a stainless steel material grade, AISI 316L is the corresponding American designation, and sus 316L is the corresponding Japanese designation. my country's unified digital code is S31603, the standard grade is 022Cr17Ni12Mo2 (new standard), and the old grade is 00Cr17Ni14Mo2, which means that it mainly contains Cr, Ni, and Mo, and the number represents the approximate percentage. The national standard is GB/T 20878-2007 (current version).

316L has a wide range of applications in the chemical industry due to its excellent corrosion resistance. 316L is also a derivative of 18-8 type austenitic stainless steel, with 2 to 3% of Mo added. On the basis of 316L, many steel grades are also derived. For example, 316Ti is derived after adding a small amount of Ti, 316N is derived after adding a small amount of N, and 317L is derived by increasing the content of Ni and Mo.

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.