Type 18Cr-9Ni-A with low C type composition, which is a very low carbon steel with a reduced carbon content between SUS304. It has excellent intergranular corrosion resistance and is also used for parts that cannot be heated after welding. The carbon content of SUS304 is generally around 0.06%, but SUS304L is narrowed down to 0.03%. Chromium is what makes steel stainless, but when stainless steel is heated to about 600 ° C to 800 ° C, the carbon contained in the material reacts with the chromium to produce chromium carbide. This is a grade of stainless steel created with the idea of ​​reducing the carbon that holds chromium in place because the chromium in it is eaten up and the chromium concentration is reduced and its corrosion resistance decreases. Stainless steel grades with L at the ends are also called L values, and are less likely to cause a phenomenon called “sensitization” in which corrosion resistance decreases due to decreased chromium concentration during heating compared to types without L. Sensitization occurs at about 650 ° C, so welding must be done with care. In simple terms compared to SUS304, SUS304L is more resistant to intergranular corrosion that is seen during welding, so it can be said to be more resistant to rust due to corrosion.

304 stainless steel

304l stainless steel