Stainless Steel 347

Type 347 has excellent intergranular corrosion resistance and oxidation resistance. at high temperatures. This material is stabilized against chromium carbide formation by the addition of columbium and tantalum. Since these elements have a stronger affinity for carbon than chromium, columbium-tantalum carbides precipitate within the grains instead of forming at the grain boundaries. 

347 should be considered for applications requiring intermittent heating between 800ºF (427ºC) and 1650ºF (899ºC) or for welding under conditions which prevent a post-weld anneal. 347 is non-magnetic.

1) It features excellent corrosion resistance comparable to 304 stainless steel.

2) It restrains chromium carbide formation, resists sensitization, and has good intergranular corrosion resistance between 427°C and 816°C.

3) It exhibits certain strength of creep resistance even in strong oxidizing environment at high temperature of 816°C.

4) It is easy to form and weld.

5) It has good low temperature toughness.

Overall, 347 has similar performance like 321 (304 plus Ti) but is superior to 321.

Stainless steel 347 Chemical Composition, %

Stainless steel 347 Mechanical Properties

Stainless steel 347 Physical Properties

Density: 7.9 g/cm3

Stainless steel 347 Equivalent Grades

Stainless steel 347 ASTM  Specification

Stainless steel 347 Application：

• Petrochemical, food, paper, etc

• Exhaust manifold and branch pipe of aero engine

• Turbine compressor hot gas pipeline

• Aircraft collector rings

• Aircraft exhaust stacks

• Boiler casings