316 and 316L stainless steel are two commonly used stainless steel materials. They have some differences in chemical composition, corrosion resistance, strength, welding treatment, high temperature resistance and price.The following is a specific analysis:

1.Different chemical composition

The carbon content of 316L stainless steel is lower than that of 316 stainless steel. In fact, the "L" in the model means ultra-low carbon. 316 stainless steel contains about 17-20% chromium, 11-14% nickel and 2-3% molybdenum, and the carbon content is about 0.08%. 316L stainless steel also contains 16-18% chromium, 10-14% nickel and 2-3% molybdenum, but its distinctive feature is that the carbon content is lower, usually controlled below 0.03%.

2.Different corrosion resistance

Due to the ultra-low carbon content of 316L, it has better resistance to grain boundary corrosion. This means that 316L will perform better in harsh environments than 316, especially in the presence of chlorides.

3.Different strengths

316 stainless steel has stronger mechanical properties and higher tensile strength than 316L stainless steel. Generally speaking, the tensile strength of 316 stainless steel is required to be greater than 520MPa, while the tensile strength of 316L stainless steel is only required to be greater than 480MPa. This is because carbon is a strong austenite-forming element that can significantly increase the strength of steel. The strength of 316L material is slightly lower than that of 316, which makes 316L easier to process and form. In some applications, this difference in strength may affect material selection.

4.Different welding processing capabilities

316 stainless steel usually requires post-weld annealing treatment after welding to restore its corrosion resistance. Due to its ultra-low carbon content.316L stainless steel has a low risk of grain boundary corrosion after welding, so annealing is usually not required.

5.Different high temperature resistance

In high temperature environments, 316L stainless steel has better carbide precipitation resistance than 316 stainless steel, so it can be used continuously in the range of 800 to 1575 degrees. When 316 stainless steel is used continuously outside this range, the material still has good heat resistance.

6.Different prices

Due to the low carbon content and easy welding of 316L stainless steel, its price is usually slightly higher than that of 316 stainless steel, but the price difference between the two is not significant.

In summary, 316L stainless steel has better corrosion resistance due to its ultra-low carbon content, especially in terms of resistance to grain boundary corrosion. In applications requiring higher strength, 316 stainless steel may be a better choice. In practical applications, the choice of 316 or 316L should be decided according to the specific use environment and requirements.