What is the difference between 304 and 304L stainless steel?

What is the difference between 304 and 304L stainless steel? In the minds of many of us, "replacing high-quality materials with low-density materials and replacing thinner materials with thickness" is natural to us. No need for multiple pipes. In fact, this view is wrong.
Take 304 stainless steel and 304L stainless steel as an example. Generally speaking, 304L has a lower carbon content than 304 and has better corrosion resistance, so it can be used instead of 304. Let's take a look at the main differences?

 

304 stainless steel vs 304L stainless steel

304 stainless steel is widely used, with good corrosion resistance, heat resistance, low temperature strength and mechanical properties, excellent hot processing properties such as stamping and bending, and no heat treatment hardening phenomenon (non-magnetic, use temperature - 196℃～800℃).
Used for household items (class I and II tableware, cabinets, indoor pipes, water heaters, boilers, bathtubs).
Automotive accessories (wipers, mufflers, molded products)
Medical equipment, building materials, chemicals, food industry, agriculture, ship parts and other fields

304L stainless steel is a low-carbon type 304 steel. Its corrosion resistance is similar to that of 304 steel under normal conditions. After welding or stress relief treatment, it has outstanding intergranular corrosion resistance and can maintain good corrosion resistance without heat treatment. The use temperature is - 196℃～800℃.
It is suitable for outdoor units, building materials heat-resistant parts, and parts that are difficult to heat treat in industries such as chemical, coal, and petroleum that require high resistance to intergranular corrosion.

 

304 and 304L stainless steel chemical composition

Grade	C	Mn	P	S	Si	Cr	Ni	N
304	0.08	2	0.045	0.03	0.75	18.00–20.00	8.00–10.50	0.1
304L	0.03	2	0.045	0.03	0.75	18.00–20.00	8.00–12.00	0.1
304H	0.04–0.10	2	0.045	0.03	0.75	18.00–20.00	8.00–10.50	-

 

304 and 304L stainless steel mechanical properties

Grade	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)	Hardness (Brinell)	Rockwell Hardness	Cold Bending
304	≥515	≥205	≥40	≥201	≥92	Not Required
304L	≥485	≥170	≥40	≥201	≥92	Not Required
304H	≥515	≥205	≥40	≥201