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ASTM A312 TP347 Stainless Steel Pipe & PMI Inspection

As everyone knows,347 stainless steel pipes are widely used in industries such as oil and gas, chemical processing, power generation, and aerospace.So why choose 347 stainless steel?

About 347 stainless steel

Stainless 347 material is often chosen for applications in high-temperature environments because of its excellent resistance to intergranular corrosion and good mechanical properties at elevated temperatures. It is a stabilized austenitic stainless steel alloy that contains columbium, which allows it to maintain its strength and corrosion resistance even after exposure to high temperatures. This makes it a popular choice for use in the chemical, petrochemical, and aerospace industries, as well as for manufacturing equipment used in high-temperature processes such as heat exchangers, boilers, and furnace components.

A312 is a specification for seamless, welded, and heavily cold worked austenitic stainless steel pipes. TP347 is a grade of stainless steel that falls under this specification.

The chemical composition of A312 TP347 is as follows:

Carbon (C): 0.08% maximum
Chromium (Cr): 17.0-20.0%
Nickel (Ni): 9.0-13.0%
Manganese (Mn): 2.0% maximum
Silicon (Si): 0.75% maximum
Phosphorus (P): 0.045% maximum
Sulfur (S): 0.030% maximum
Columbium (Nb) + Tantalum (Ta): 10x(Carbon content) – 1.00% maximum
Nitrogen (N): 0.10% maximum
These chemical ingredients contribute to the excellent high-temperature strength and corrosion resistance of TP347 stainless steel. It is commonly used in applications involving elevated temperatures, such as in the manufacturing of heat exchangers, boiler tubes, and other high-temperature equipment in the chemical, petrochemical, and power generation industries.


A312 TP347 Composition Analysis


About TP347 PMI Inspection

PMI inspection, which stands for Positive Material Identification, is a non-destructive testing method used to verify the composition of materials, including stainless steel. Stainless 347 is a stabilized austenitic stainless steel alloy. PMI inspection for stainless 347 material involves using handheld X-ray fluorescence (XRF) analyzers or other testing methods to determine the elemental composition of the material. This helps ensure that the material meets the required specifications and is suitable for its intended application.

Cost difference between 347 and 347h stainless steel?

The 347 stainless steel is austenitic chromium nickel stainless steel that is stabilized with columbium and tantalum. The major difference between the 347 and the 347H is the carbon content. So there is not much difference in the cost of the material. If there is cost difference, it is due to the lower use cases of the 347h that the manufacturers don’t have to produce much of the material in the same volume as the 347 material.

Both are corrosion resistant, heat resistant and have high tensile strength and yield strength. Both materials can be used in chemical processing plants, boilers, super heater elements and in other high temperature services. In these applications, there are some instances where the hardness and toughness of the material needs to be higher.

The 347h is used exactly for that. The manufacturing cost per unit decreases with the volume of production. The transportation, storage and other service costs also go down with the volume of production. The 347 is produced in high quantities than the 347h because the 347 is the most used. It is due to these reasons, the 347h cost might be slightly more than that of 347.


Go to view related types of products Stainless Steel 347 Pipe Fittings



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