Stainless steels get their names from the American Iron & Steel Institute (AISI) and the Society of Automotive Engineers (SAE), who have separately created their own naming systems for steel alloys based on alloying elements, uses, and other factors. Steel names can get confusing, as the same alloy can have different identifiers depending on which system is used; however, understand that the chemical composition of most alloy blends remains the same across classification systems. In the case of stainless steels, they are often composed of 10 to 30% chromium and are made to withstand varying degrees of corrosion exposure. To learn more about the differences among stainless steels, feel free to read our article on the type of stainless steel.
Type 304 steel is part of the 3xx stainless steels or those alloys which are blended with chromium and nickel. Below is a chemical breakdown of 304 steel:
<=0.08% carbon
18-20% chromium
66.345-74% iron
<= 2% manganese
8-10.5% nickel
<=0.045% phosphorus
<=0.03% sulfur
<=1% silicon
The density of 304 steel is around 8 g/cm3, or 0.289 lb/in3. Type 304 steel also comes into three main varieties: 304, 304L, and 304H alloys, which chemically differ based on carbon content. 304L has the lowest carbon percentage (0.03%), 304H has the highest (0.04-0.1%), and balanced 304 splits the difference (0.08%). In general, 304L is reserved for large welding components that do not require post-welding annealing, as the low carbon percentages increase ductility. Conversely, 304H is most used in elevated temperatures where the increased carbon content helps preserve its strength while hot.
Type 304 steel is austenitic, which is simply a type of molecular structure made from the iron-chromium-nickel alloy blend. It makes 304 steel essentially non-magnetic, and gives it a lower weakness to corrosion between grains thanks to austenitic steels being generally low carbon. 304 steel welds well using most welding methods, both with and without fillers, and it easily draws, forms, and spins into shape.
Post time: Jan-10-2022