AISI 304 is used in a variety of household and industrial applications. 304L is an even lower carbon version of 304 stainless steel and can be used in more corrosive environments such as salt water and chemical containers. Both 304 and 304L can be used in the welded condition as opposed to the annealed condition and still maintain resistance to corrosion and lend themselves to many types of fabrication. These grades resist corrosion and are often used in the food industry.
304L: % C≤0.03 Si ≤1.0 Mn ≤2.0 Cr 18.0～20.0 , Ni 8.0～11.0, S ≤0.03 P ≤0.035 304: % C≤0.08 Si≤1.00 Mn ≤2.00 P≤0.05 S≤0.03 Cr 18.00-20.00 Ni 8.00~10.50
The big difference between 304 and 304L is the Carbon percentage, 304L carbon percentage below 0.03%, while 304 carbon percentage below 0.08%.
Grade 201 stainless steel, it is a material should have features, such as certain resistance from acid and alkali, high density, polishing without bubbles, no pinholes and other characteristics, it can be used in a variety of applications, for decorative pannels, pipes, industrial pipes, some shallow stretching products.
Because there is no national standard, 201 stainless steel were catogrized into 5 types, J4, J1, J3, J2 and J5, due to their different composition and application fields.
Here following are the chemical compositions:
*The actual chemical composition percentage may vary a little bit
Well, this is a nice question, stainless steel is famous not for its abilities of anti-scratch, but for its ability to resist rust, anti-scratches ablity depends on it's hardness, and its hardness varies depends on the grade of stainless steel, and also surface finish matters when you come up with such question, most cold rolled stainless steel sheet are for decorative use or function use, it has fine surface after processing, just like a stainless steel watch, you may find something interesting is that a very expensive watch may get scratches on its belt and body too, but if you use a embossed stainless steel sheet, you may find the scratches are not so visible as mirror one, and stainless steel sheet for spring will not have scratches as its hardness is very high. Therefore, here is our advise, do gentle with decorative stainless steel sheets, do not use any abrasive material in cleaning, use soft things, its shinny surface can remain long.