304/304L
General Information:
Also known as Stainless steel types 1.3201 and 1.4307, alloy 304 is an austenitic grade of stainless steel. It has the property of being able to be severely deep drawn. It is commonly used in sinks and saucepans.
Alloy 304 is the low carbon version of 304 stainless steel. The lower carbon gives the steel improved weldability.
Some pipes and plates may be "dual certified" material. This means that they fit the criteria for both 304 and 304L.
Chemical Composition:
Typical Chemical Composition Element % in 304 % in 304L C 0.08 max .03 max Mn 2.0 2.0 Si 0.75 0.75 P 0.045 0.045 Si 0.03 0.03 Cr 18-20 18-20 Ni 10.5 12 N 0.1 0.1
Mechanical Properties:
Typical Mechanical Properties 304 304L Tensile Strength (MPa) 520 500 Compression Strength (MPa) 210 210 Proof Stress 0.2% (MPa) 210 200 Elongation A5 (%) 45 45 Hardness Rockwell B 92 92
Physical Properties:
Typical Physical Properties
Property
Density
Value
8.00g/cm3
Melting Point 1400-1450°C Modulus of Elasticity 193 GPa Electrical Resistivity 0.072 x 10-6 Ω.m Thermal conductivity 16.2 W/m.K at 100°C Thermal Expansion 17.2x10-6 /K at 100°C
Alloy Designations
Euronorm UNS BS En Grade 304S15 1.4301 S30400 304S16 58E 304 304S31 1.4306 S30403 304S11 -- 304L 1.4307 -- 304S11 -- 304L 1.4311 -- 304S11 -- 304L 1.4948 S30409 304S51 -- 304H
Corrosion and Heat Resistance:
Alloy 304 has very high corrosion resistance in many environments even when in contact with different corrosive material. Some pitting and crevice corrosion can be happen, however, when it is put into contact with chlorides. Stress corrosion cracking may also occur if temperatures exceed 60°C.
If used in intermittent service, alloy 304 has good oxidation resistance up to 870°C. In continuous service, it has good oxidation resistance up to 925°C. It is not recommended, however, for continuous use at 425-860°C if corrosion resistance in water is necessary. In those circumstances alloy 304L is more suitable due to its resistance to carbide precipitation.