Stainless steel 304 and 316L are two common grades of austenitic stainless steel, and they differ in their chemical composition. While they are both corrosion-resistant, 316L is more corrosion-resistant. The differences between the two are detailed below.
First, the chemical composition is different.
There is a significant difference in the chemical composition of stainless steel 304 and 316L. The C content of 304 stainless steel is 008% with a CR content of 1800-20.00%, Ni content is 800-11.00%；Whereas, 316L stainless steel has a C content of 003%, CR content is 1600-18.00%, Ni content is 1000-14.00%。In addition, 316L stainless steel also contains the MO element, which is usually 2.00-3.00%。
Second, the mechanical properties are different.
Due to differences in chemical composition, 304 and 316L also differ in terms of mechanical properties. 304 stainless steel has better tensile strength, yield strength, and elongation, while 316L has higher tensile strength, yield strength, and elongation. In addition, 316L has a slightly lower hardness than 304.
Third, the corrosion resistance is different.
The corrosion resistance of stainless steel depends mainly on the chromium and nickel elements it contains. 304 stainless steel contains enough chromium and nickel elements to have good corrosion resistance. Whereas, 316L stainless steel contains more molybdenum elements, which makes it more resistant to corrosion. In marine environments, 316L has better corrosion resistance because it is more resistant to rust.
Fourth, the use is different.
Due to their different corrosion resistance and mechanical properties, 304 and 316L have different areas of application. 304 stainless steel is widely used in household goods, food industry, medical equipment, and other fields because of its good mechanical properties and corrosion resistance. 316L, on the other hand, is mainly used in the marine engineering, chemical industry, food industry and medical fields, especially in high chloride environments, because of its stronger corrosion resistance.
In conclusion, both 304 and 316L stainless steel have good corrosion resistance, but 316L has stronger corrosion resistance. When choosing which stainless steel to use, the decision needs to be made based on the specific application environment and requirements.