The 347 stainless steel tube is an austenitic stainless steel tube containing a stabilizing element of niobium. Its typical chemical composition includes 17.0% - 19.0% chromium, 9.0% - 13.0% nickel, and a niobium content not less than 10 times that of carbon. The addition of niobium distinguishes it from ordinary 304 or 316 stainless steel. The core advantage lies in its excellent intergranular corrosion resistance and good high-temperature strength, which is suitable for the sensitization temperature range of 450℃ to 850℃ and higher temperature conditions.
In terms of performance features, the 347 stainless steel tube has three major advantages. Firstly, it has excellent intergranular corrosion resistance. Nitrogen combines with carbon preferentially to form carbide-nitrogen, preventing chromium carbides from precipitating at the grain boundaries, ensuring good corrosion resistance even after welding or high-temperature service. Secondly, it has excellent high-temperature mechanical properties. It can maintain high yield strength and creep resistance within the range of 600℃ to 800℃, making it suitable for high-temperature equipment such as boilers, superheaters, and heat exchangers. Thirdly, its processing performance is stable. The material has good cold and hot processability and weldability, and can be safely used without the need for subsequent solution treatment after welding.
Regarding the material selection guide, it is recommended to give priority to 347 stainless steel tubes in the following scenarios: equipment that needs to be used for a long time within the sensitization temperature range; large components that cannot undergo heat treatment after welding; and chemical pipelines and pressure vessels with operating temperatures exceeding 400℃. If only used in normal temperature or low-temperature corrosive environments, 304 or 316 stainless steel may offer greater cost advantages.
Jiangsu Cunrui Metal Products Co., Ltd. Specialized in supplying 347 stainless steel pipes, with a wide range of specifications and sufficient stock in stock. Technical selection support is also available.
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