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347/H
1.4550 / 1.4912

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

347 and 347H 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, 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 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.

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

As you can see, the main difference between the two alloys is that 347H has a higher carbon content (0.04-0.10%) than 347 (0.08% maximum). This higher carbon content is what gives 347H its improved high temperature strength.

It is important to note that the chemical composition of these alloys may vary depending on the manufacturer or supplier and it is always recommended to check the certificate of analysis before using it in any application.

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) .

The high temperature mechanical properties of 347H are also better than 347, as it has higher creep resistance and stress rupture properties. 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. Therefore, it is always recommended to consult with the manufacturer or supplier to obtain the specific properties of the alloy that you are using.

Physical & Mechanical Properties of 347/347H

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 stabilized 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: This variant of 347 alloy is a high-carbon version of the alloy, which is designed to have improved high-temperature strength. 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 just a few examples of the variants of 347 alloy, and there may be others available depending on the manufacturer or supplier. It is important to consult with the manufacturer or supplier to determine the specific properties and performance characteristics of the variant that you are interested in using.

AVAILABLE FORMS

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

Stacked Pipes
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Intamet-03269.jpg
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