Applications
Grade 304L Stainless Steel is used in a wide variety of commercial and industrial applications, including:
· Food processing equipment, particularly in beer brewing, milk processing, and wine making
· Architectural trim and molding
· Automotive and aerospace structural use
· Construction material in large buildings
· Chemical containers, including for transport
· Heat exchangers
· Nuts, bolts, screws, and other fasteners in the marine environment
· Woven or welded screens for mining, quarrying & water filtration
Standards
· ASTM/ASME: S30403
· EURONORM: 1.4303
· AFNOR: Z2 CN 18.10
· DIN: X2 CrNi 19 11
Corrosion Resistance
· Resistance to corrosion in oxidizing environments is a result of the 18 to 19% chromium that the 304 alloys contain.
· Resistance to moderately aggressive organic acids is a result of the 9 to 11% nickel that the 304 alloys contain.
· At times, grade 304L may show a lower corrosion rate than the higher carbon Alloy 304; otherwise, the 304, 304L, and 304H may be considered to perform uniformly in most corrosive environments.
· Grade 304L is preferred for use in environments sufficiently corrosive to cause intergranular corrosion of welds and heat-affected zones on susceptible alloys.
Heat Resistance
· Good oxidation resistance in intermittent service to 1600°F and in continuous service to 1690°F.
· Continuous use of 304 in the 800-1580°F range is not recommended if subsequent aqueous corrosion resistance is important.
· Grade 304L is more resistant to carbide precipitation and can be heated into the above temperature range.
Welding Characteristics
Excellent welding properties; post-weld annealing is not required when welding thin sections. Two important considerations in producing weld joints in the austenitic stainless steels are:
1. preservation of corrosion resistance
2. avoidance of cracking
Processing - Hot Forming
· To forge, heat uniformity to 2100 / 2300 °F
· Do not forge below 1700 °F
· Forging can be air cooled without danger of cracking
Processing - Cold Forming
· Its austenitic structure allows it to be deep-drawn without intermediate annealing.
· These grades work harden rapidly. To relieve stresses produced in severe forming, parts should be full annealed or stress relief annealed as soon as possible after forming.
Machinability:
· The use of chip breakers is advised since the chips can be stringy. Stainless steel work harden rapidly, heavy positive feeds, sharp tooling, and a rigid set-up should be used.
Chemical Properties
C Mn Si P S Cr Ni N 304L 0.07max 2.0max 0.75max 0.045max 0.03max min: 18.0 max: 20.0 min: 8.0 max: 10.5 - Mechanical Properties
Grade Tensile Strength ksi (min) Yield Strength 0.2% ksi (min) Elongation % Hardness (Brinell) MAX Hardness (Rockwell B) MAX 304L 75 30 40 201 92 Physical Properties
Density lbm/in3 Thermal Conductivity (BTU/h ft. °F) Electrical Resistivity (in x 10-6) Modulus of Elasticity (psi x 10-6) Coefficient of Thermal Expansion (in/in)/ °F x 10-6 Specific Heat (BTU/lb/°F) Melting Range (°F)) at 68°F: 0.285 9.4 at 212°F 28.3 at 68°F 28 9.4 at 32 – 212° 0.1200 at 68°F to 212°F 2500 to 2590 12.4 at 932 °F 39.4 at 752°F 10.2 at 32 – 1000°F 49.6 at 1652 °F 10.4 at 32 – 1500°F