ThePipingMart Blog Grades 347H Stainless Steel (UNS S34709) – Composition, Properties, and Uses

347H Stainless Steel (UNS S34709) – Composition, Properties, and Uses

347H Stainless Steel

In recent years, the popularity of stainless steel (ss) has grown exponentially. It’s now one of the most widely used materials in many industries, thanks to its ability to withstand corrosion and high temperatures. One type of stainless steel that has become increasingly popular is 347H stainless steel. This grade of steel offers greater resistance to corrosion and oxidation than other grades and can be used in a variety of applications. Let’s take a closer look at what makes this material so special.

347H Stainless Steel Composition

The composition of 347H ss consists primarily of iron, chromium, and nickel. It also contains trace amounts of carbon, manganese, phosphorus, sulfur, silicon, and aluminium. This combination gives it excellent corrosion resistance and mechanical properties at elevated temperatures up to about 850°F (454°C). It’s also non-magnetic in nature.

C Cr Mn Ni P S Si Cb/Ta
347 0.08 max min: 17.0
max: 20.0
2.0 max min: 9.0
max: 13.0
0.04 max 0.30
max
0.75
max
min:10x C
max: 1.0
347H min: 0.04
max: 0.10
min: 17.0
max: 20.0
2.0 max min: 9.0
max: 13.0
0.03 max 0.30
max
0.75
max
min:10x C
max: 1.0

347H Stainless Steel Physical Properties

The physical properties of stainless steel 347H include high tensile strength (up to 870MPa) as well as excellent ductility and malleability, even at low temperatures. Its uniform structure provides superior formability without sacrificing strength or toughness. The material is highly resistant to stress cracking and crevice corrosion due to its good weldability characteristics, with no preheating necessary before welding operations can begin.

Density
lbm/in^3
Coefficient of
Thermal Expansion (min/in)-°F
Thermal Conductivity BTU/hr-ft-°F Specific Heat BTU/lbm -°F Modules of Elasticity (annealed)^2-psi
at 68 °F at 68 – 212°F at 68 – 1832°F 68-932°F at 32 – 212°F in tension (E)
0.288 9.2 11.4 14.7 0.12 28 x 10^6

347H Stainless Steel Mechanical Properties

The mechanical properties of aisi 347h stainless steel are impressive when compared to other grades of steel. Its yield strength stands at around 205MPa, while its ultimate tensile strength measures up to 870MPa after cold working processes have been performed on the material. The material has great impact strength as well as excellent fatigue behaviour due to its ability to retain its shape even after being exposed repeatedly over time or through extreme temperature changes. Additionally, this grade offers good machinability even though it’s difficult to work with in some ways due to its hardness—it can be drilled using standard tools but requires more time for cutting operations due to its higher levels of wear resistance compared with other steels such as 304L or 316L grade steels.

Grade Tensile Strength ksi (MPa) min Yield Strength 0.2% ksi offset ksi (MPa) min Elongation (% in 50mm) min Hardness (Brinell) MAX Hardness (Rockwell B) MAX
347/347H 75
(515)
30
(205)
40 201 95

347H Stainless Steel Equivalent

  • UNS S34709
  • ASTM A240
  • ASTM A480
  • ASME 240

347H Stainless Steel Uses

347H ss is an especially useful and popular metal for industrial applications because it is both strong and easily welded into shapes. Its high chromium, nickel, and carbon content make it uniquely well-suited to use in environments with exposure to higher temperatures, making it the ideal choice for heat exchangers, manifolds, turbochargers, auto exhaust systems, and pipelines. Additionally, its tensile strength makes it invaluable in many of the more complex structures we rely on in commercial settings–support beams, lattices, frames and so on. Of further note is its versatility–347H stainless steel can be formed into a vast array of shapes thanks to its high ductility. With this combined list of features in mind, you can begin to understand why aisi 347h stainless steel has become such an essential part of modern industry.

Conclusion

In conclusion, 347H stainless steel is an ideal choice for many applications because it offers superior corrosion resistance and mechanical properties at elevated temperatures up to about 850°F (454°C). Its composition consists mainly of iron, chromium, and nickel, along with trace amounts of other elements like carbon, manganese, phosphorus, sulfur, silicon, and aluminium, which give it high tensile strength (up to 870MPa) along with good formability without sacrificing toughness or strength. Additionally, this grade has great impact strength as well as excellent fatigue behaviour, making it suitable for many industrial applications such as petrochemical plants, nuclear power plants, oil refineries, automotive exhaust systems, food processing machinery, pressure vessels etc. We hope this comprehensive guide helps you understand why this unique grade is so popularly used today!

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