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ASTM A213 TP347H is a high-carbon austenitic stainless steel tube grade manufactured under the ASTM A213 / ASME SA213 specification for high-temperature and high-pressure service. This grade is a stabilized stainless steel containing niobium (columbium), which prevents carbide precipitation and enhances resistance to intergranular corrosion during welding and prolonged heating.
The “H” designation in TP347H indicates a higher carbon content compared to standard 347 stainless steel, which improves creep resistance, stress-rupture strength, and structural stability when exposed to elevated temperatures for extended periods. Because of these properties, ASTM A213 TP347H tubes are commonly used in boilers, superheaters, reheaters, heat exchangers, and petrochemical heater systems where reliable performance at temperatures above 600°C is required.