Stainless Steel Grade AISI 348 | UNS S34800

AISI 348 | UNS S34800 - is an austenitic stainless steel stabilized with niobium (columbium) / tantalum. The alloy has excellent resistance to intergranular corrosion. This steel should be considered for applications subject to intermittent heating at temperatures between 425 ºC - 900 ºC. The steel contains 18 - 20% chromium and 9 - 13% nickel.

Steel also contains certain amounts of carbon, manganese, phosphorus, sulfur, and silicon. These elements combine to create an alloy that is resistant to corrosion and rust and has excellent heat-resistant properties. This makes it an ideal material for use in extreme environmental conditions, such as high-temperature industrial environments or areas with high humidity or high moisture levels.

Steel density = 7.8 g/cm³. Non-magnetic. AISI 348 is very similar in its properties to stainless steel AISI 321.

Mechanical properties

Welding

The alloy can be welded using shielded fusion and resistance methods, but oxyacetylene welding should not be used due to the risk of carbon absorption in the weld. AISI 347 filler metal should be used if necessary. For optimum corrosion resistance after welding or for use at elevated temperatures, stabilisation by post weld treatment is recommended.

Forging

Before forging, the material should be heated uniformly to a forging temperature of 1150 ºC - 1230 ºC. Do not work below 925 ºC. Forgings can be air cooled, but for maximum corrosion resistance, forgings should be water quenched and then annealed.

Cold processing

AISI 348 grade stainless steel is ductile and strong, and can be easily stamped, drawn and formed.

Annealing

Stainless steel grade AISI 348 is annealed at a temperature of 1010 °C - 1093 °C, followed by quenching in water.

Hardening

Stainless steel of this grade does not react to heat treatment. However, improved properties can be obtained by cold reduction.