required), Corrosion resistance SO2 test (for required), Porosity Test (for required), Pickling lag value (for required).2. What are different features between TFS and ETP?A. Appearance - Even when the same surface finish as ETP is applied to the substrate steel sheet, it provides the unique surface luster characteristic of metllic chromium.B. Corrosion resistance - As it has excellent corrosion resistance after painting, it is generally used with both surfaces painted. It can also be used with