General Properties

Alloy 304 series stainless steel austenitic, which has a minimum of 18% chromium and 8% nickel. Type 304 has a maximum carbon of 0.08% . It is the standard “18/8 stainless” that is commonly found in pans and cooking tools. Alloy 304 is the most versatile and widely used alloy in the stainless steel family. Ideal for a wide variety of home and commercial applications, Alloy 304 exhibits excellent corrosion resistance and has a high ease of fabrication, outstanding formability. The austenitic stainless steels are also considered to be the most weldable of the high-alloy steels and can be welded by all fusion and resistance welding processes.

Specifications: UNS S30400

Alloy 304 Stainless Steel is used in a wide variety of home and commercial applications, including:

• Kitchen benches, sinks, troughs, equipment, and appliances
• 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
• Dyeing industry

Standards:

• ASTM/ASME: UNS S30408 / S30403
• EURONORM: 1.4301 / 1.4303
• AFNOR: Z5 CN 18.09 / Z2 CN 18.10
• DIN: X5 CrNi 18 10 / X2 CrNi 19 11

Corrosion Resistance:

• 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.

Heat Resistance:

• 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.

Properties of 304 Alloy

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. avoidance of cracking
2. 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.

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.of cut below the work-hardened layer resulting from the previous passes.