347H/ 1.4550/1.4912 Stainless Steel | Intamet Ltd

347 and 347H Stainless Steel are variants of stainless steel 347, with 347H having higher carbon content and improved strength at high temperatures.

347 and 347H Stainless Steel are both types of stainless steel alloys. They are both variations of the austenitic stainless steel alloy, which is a type of steel that contains chromium and nickel and is known for its corrosion resistance and high strength.

347 is a variation of the alloy that contains columbium/ STinl, which is also known as niobium, and tantalum. These elements are added to the alloy to improve its resistance to intergranular corrosion, which is a type of corrosion that can occur when the steel is heated to high temperatures. 347 is also known for its good formability and weldability.

347H is a higher carbon version of 347 alloy, which is designed to have improved high temperature strength. This alloy is commonly used in applications that require high temperature resistance, such as in the aerospace and power generation industries. Additionally, it is also useful in applications that require high resistance to stress corrosion cracking.

Both alloys are non-magnetic and have good corrosion resistance in a variety of environments, including those with elevated temperatures. They are often used in applications that require both strength and corrosion resistance, such as in the construction of boilers and heat exchangers.

347 and 347H Stainless Steel are also used in the production of high-temperature fasteners, such as nuts, bolts, and screws. They are also used in the chemical and petrochemical industries, as well as in the food and beverage industry.

In summary, 347 and 347H are both austenitic stainless steel alloys that have good corrosion resistance and high strength. 347 is known for its resistance to intergranular corrosion, while 347H is designed to have improved high temperature strength. Both alloys are commonly used in a wide range of industries and applications that require strength and corrosion resistance.

Physical & Mechanical Properties of 347/347H

The physical and mechanical properties of 347 and 347H stainless steel alloys are similar, but there are some slight differences due to the different carbon content of the two alloys.

Physical Properties:

  • Density: 8 g/cm3
  • Melting Point: 1454-1495 °C (2650-2750 °F)
  • Modulus of Elasticity: 193 GPa (28 x 106 psi)

Mechanical Properties (at room temperature):

  • Tensile Strength: 515-655 MPa (75-95 ksi)
  • Yield Strength: 205-345 MPa (30-50 ksi)
  • Elongation: 40-50%
  • Hardness (Brinell): 217-269 HB

347H has higher strength properties than 347. The Tensile strength of 347H is typically around 515-655 MPa (75-95 ksi) and Yield strength is 205-345 MPa (30-50 ksi) .

​347H has better high-temperature mechanical properties than 347, with higher resistance to creep and stress rupture. This makes it suitable for applications that involve high temperatures, such as in the aerospace and power generation industries.

​It is important to note that these properties may vary depending on the heat treatment, fabrication, and other factors. Always consult the manufacturer or supplier for the specific properties of the alloy you are using.

Chemical Composition of 347/347H

The chemical composition of 347 and 347H stainless steel alloys are quite similar, with the main difference being the carbon content. The chemical composition of 347 alloy typically includes:

  • Carbon (C): 0.08% maximum
  • Manganese (Mn): 2.00% maximum
  • Phosphorus (P): 0.045% maximum
  • Sulfur (S): 0.030% maximum
  • Chromium (Cr): 17.00-20.00%
  • Nickel (Ni): 9.00-13.00%
  • Nitrogen (N): 0.10% maximum
  • Columbium (Cb) + Tantalum (Ta): 10x(C+N) min
  • Iron (Fe): Balance

The chemical composition of 347H alloy typically includes:

  • Carbon (C): 0.04-0.10%
  • Manganese (Mn): 2.00% maximum
  • Phosphorus (P): 0.045% maximum
  • Sulfur (S): 0.030% maximum
  • Chromium (Cr): 17.00-20.00%
  • Nickel (Ni): 9.00-13.00%
  • Nitrogen (N): 0.10% maximum
  • Columbium (Cb) + Tantalum (Ta): 10x(C+N) min
  • Iron (Fe): Balance

The main difference between the two alloys is that 347H has more carbon (0.04-0.10%) than 347 (0.08% max). This higher carbon content is what gives 347H its improved high temperature strength.

The alloys' chemical composition can differ based on the manufacturer or supplier. It's advised to check the analysis certificate before using them in any application.

Variants of 347

There are several variants of the 347 stainless steel alloy, which are designed to provide specific properties or performance characteristics. Some common variants of 347 include:

  1. 347F: This variant of 347 alloy is designed to have improved formability and better low-temperature toughness than standard 347. It is often used in applications that require cold working, such as in the construction of cryogenic vessels.
  2. 347L: This variant of 347 alloy is a low-carbon version of the alloy, which is designed to have improved weldability. It is often used in applications that require welding, such as in the construction of boilers and heat exchangers.
  3. 347S: This variant of 347 alloy is a stabilised version of the alloy, which is designed to have improved resistance to intergranular corrosion. It is often used in applications that involve high temperatures, such as in the aerospace and power generation industries.
  4. 347H is a high-carbon version of 347 alloy, made to have better strength at high temperatures. It is often used in applications that require high-temperature resistance, such as in the aerospace and power generation industries.
  5. 347N: This variant of 347 alloy is a nitrogen-strengthened version of the alloy, which is designed to have improved strength and corrosion resistance. It is often used in applications that involve high temperatures, such as in the aerospace and power generation industries.

These are some examples of 347 alloy types, and there might be more options depending on the maker or seller. Consult the manufacturer or supplier to find out the specific properties and performance of the variant you want to use.

AVAILABLE FORMS

Intamet offers 347 in a wide range of forms, including the below:

 
Stacked Pipes

Tubes & Pipes

BOX

Hollow Sections

fittings

Fitting & Flanges

Intamet-03269

Round Bars

Stainless_Steel_Plate

Sheet & Plate