347 Stainless Steel (UNS S34700) – Composition, Properties, and Uses

347 stainless steel, also known as UNS S34700, finds a diverse range of applications across multiple industries with its unique composition and remarkable properties. In this article, we will explore the composition, mechanical properties, corrosion resistance, heat resistance, welding characteristics, and primary uses of 347 stainless steel.

347 Stainless Steel (UNS S34700) – Composition, Properties, and Uses

I. Composition:

The composition of 347 stainless steel is tailored to provide exceptional corrosion resistance and heat resistance. It primarily consists of iron, chromium, and nickel, with specified additions of carbon, manganese, silicon, and other elements. The chromium content, typically ranging from 17 to 19%, is responsible for the steel’s corrosion resistance, while the nickel content, ranging from 9 to 13%, enhances its ductility and toughness. Additionally, 347 stainless steel contains small amounts of titanium or columbium (Cb) to stabilize the austenitic structure during welding and prevent grain boundary carbide precipitation.

II. Mechanical Properties:

347 stainless steel exhibits exceptional mechanical properties, making it suitable for a wide range of applications. It offers high strength, good ductility, and toughness, even at elevated temperatures. The ultimate tensile strength of 347 ss typically ranges from 515 to 725 MPa, with a yield strength of approximately 205 MPa. It also demonstrates good impact resistance, making it suitable for use in low-temperature environments.

III. Corrosion Resistance:

347 stainless steel’s high chromium and nickel content confer excellent corrosion resistance in a wide range of environments. It is particularly resistant to corrosion in oxidizing environments and can withstand exposure to nitric acids, organic acids, and certain inorganic acids. However, it is important to note that the corrosion resistance of 347 ss may be compromised in strongly reducing environments, such as hydrochloric acid.

IV. Heat Resistance:

One of the standout features of 347 ss is its heat resistance. It can maintain its mechanical properties and corrosion resistance even at elevated temperatures, making it suitable for use in high-temperature applications. The addition of titanium or columbium in 347 ss stabilizes the austenitic structure, preventing grain boundary carbide precipitation and maintaining its ductility and toughness at high temperatures.

V. Welding Characteristics:

347 ss is known for its excellent welding characteristics. It can be welded using a variety of welding processes, including fusion welding and resistance welding. The addition of titanium or columbium in 347 ss minimizes the risk of welding-induced sensitization and grain boundary carbide precipitation, ensuring good weldability and weld metal properties. Post-weld heat treatment is generally not required, but it can be performed to improve the corrosion resistance and mechanical properties of the weld joint.

VI. Applications:

Thanks to its combination of corrosion resistance, heat resistance, and mechanical properties, 347 stainless steel finds applications in numerous industries. Here are some of its primary applications:

1. Oil and Gas Industry: In the oil and gas industry, 347 ss is used in the construction of pipelines, valves, pumps, heat exchangers, and other equipment exposed to high temperatures and corrosive environments.
2. Chemical Processing Industry: The chemical processing industry requires materials that can withstand exposure to harsh chemicals and elevated temperatures. 347 ss is a popular choice for fabricating reactors, storage tanks, distillation columns, and other equipment.
3. Power Generation Industry: In power plants, 347 ss is used in the construction of superheaters, reheaters, turbines, and other components exposed to high temperatures and corrosive environments.
4. Automotive Industry: The automotive industry benefits from the lightweight and corrosion-resistant properties of 347 ss. It is used in the manufacture of exhaust systems, fuel systems, and other components exposed to high temperatures and corrosive exhaust gases.
5. Pharmaceutical and Food Processing Industries: The pharmaceutical and food processing industries require materials that are hygienic and resistant to corrosion. 347 stainless steel is widely used in the manufacture of processing equipment, storage tanks, and piping systems.

Conclusion

In conclusion, 347 stainless steel (UNS S34700) offers a unique combination of corrosion resistance, heat resistance, and mechanical properties, making it a highly sought-after material across various industries. Its diverse applications range from oil and gas to automotive and pharmaceutical industries, testament to its versatility and reliability.

If you are looking for 347 stainless steel (UNS S34700) suppliers online now, please don’t hesitate to contact Sino Stainless Steel. As a leading supplier of stainless steel products from Shanghai, China, Sino Stainless Steel provides customers with high-quality 347 stainless steel, cold-rolled stainless steel sheets, colored stainless steel sheets, stainless steel pipes, stainless steel strips, stainless steel plates, stainless steel bars, and stainless steel tubes at an extremely competitive price.