Alloy 304 Stainless Steel is used in a wide variety of home and commercial applications, including:
- Chemical containers, including for transport
- Food processing equipment, particularly in beer brewing, milk processing, and wine making
- Heat exchangers
- Architectural trim and molding
- Woven or welded screens for mining, quarrying & water filtration
- Automotive and aerospace structural use
- Nuts, bolts, screws, and other fasteners in the marine environment
- Construction material in large buildings
- ASTM/ASME: UNS S30400 / S30403
- EURONORM: 1.4301 / 1.4303
- AFNOR: Z5 CN 18.09 / Z2 CN 18.10
- DIN: X5 CrNi 18 10 / X2 CrNi 19 11
- Resistance to moderately aggressive organic acids is a result of the 9 to 11% nickel that the 304 alloys contain.
- Resistance to corrosion in oxidizing environments is a result of the 18 to 19% chromium that the 304 alloys contain.
- The 304, 304L, and 304H may be considered to perform uniformly in most corrosive environments.
- Continuous use of 304 in the 800-1580°F range is not recommended if subsequent aqueous corrosion resistance is important.
- Good oxidation resistance in intermittent service to 1600°F and in continuous service to 1690°F.
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:
- avoidance of cracking
- preservation of corrosion resistance
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, Making this the stainless steel grade of choice in the manufacturing of sinks, hollow-ware and saucepans.
- These grades work harden rapidly. To relieve stresses produced in severe forming or spinning, parts should be full annealed or stress relief annealed as soon as possible after forming.
- 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.
C Mn Si P S Cr Ni N 304 0.07max 2.0max 0.75max 0.045max 0.03max min: 18.0 max: 20.0 min: 8.0 max: 10.5 -
Grade Tensile Strength ksi (min) Yield Strength 0.2% ksi (min) Elongation % Hardness (Brinell) MAX Hardness (Rockwell B) MAX 304 7 25 40 201 92
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