AISI 309Cb+Ta Stainless Steel Chemical Composition & Properties, Grades, Charts and Online Pdf

AISI 309Cb+Ta is well-known for its exceptional ability to resist some forms of corrosion and oxidation in high-temperature environments due to its being an austenitic type of stainless steel. The chemical composition of superalloy commonly contains as chromium, nickel - about 23% and 12%, respectively, with earlier small additions of columbium and tantalum, with their high-temperature stability and working level improving. This rating is better than the others regarding resistance to oxidation, carburization and thermal cycling, which allows its use in the most demanding environment such exhaust systems, petrochemical plants and heating treatment furnaces. As a result of the addition of tantalum and columbium to the steel, more grain boundary stability is promoted, that minimizes sensitization and corrosion susceptibility originating from the grain boundaries. The AISI 309Cb+Ta is highly regarded as a suitable material because it is offered in various shapes, such as sheets, plates, bars and seamless tubes which broaden the technology field in engineering applications. Charts and PDFs that are easy to access offer better specification information that can be easily incorporated into the design and manufacturing processes.

AISI 309Cb+Ta Austenitic Stainless Steel Chemical Composition And Grade Table

AISI 309Cb +Ta is hybrid stainless steel which is austenitic (its general element) with tantalum and niobium (Ta and Cb) added to enhance its properties. Most of the time, its chemical composition includes 22% chromium and 12% nickel, with the niobium and tantalum compared to 7% of the total amount. This helps to increase the strength and resistance against corrosion at high temperatures. This alloy has the ability to resist well oxidation and carburation at high temperature, therefore we can very well say this alloy is able to be applicable for furnace components and heat treatment equipment manufacturing in high temperature condition. It stands out due to its strong austenitic structure, which is known for high durability even in the toughest circumstances.

AISI 309Cb+Ta Austenitic Stainless Steel
Elements Fe Cr Ni Mn Cb Si C P S
Min (%) 56 22 12 - - - - - -
Max (%) 66 24 16 2.0 1.1 0.75 0.080 0.045 0.030

The Advantages and Disadvantages of AISI 309Cb+Ta Austenitic Stainless Steel


  • Corrosion Resistance: AISI 309Cb+Ta stainless steel displays as much as possible corrosion resistance in different environments such as acidic and high-temperature ones.

  • High Strength: It has a good tensile strength and durability, making it a great choice to apply in structural spaces where strength is essential.

  • Formability: AISI 309Cb+Ta is a material that is easier to form and manufacture into different shapes enabling for diverse construction.

  • Weldability: Its low carbon content not only improves weldability, but also facilitates assembly and welding processes. Consequently, working with it would be less complicated.

  • Temperature Resistance: AISI 309Cb+Ta offers amazing performance at high temperatures because it is stable and reliable under extreme conditions.


  • Magnetic Properties: AISI 316 stainless steel is commonly magnetically by the mild magnetic effect what can lead to the rejection by some applications where magnetism is not required.

  • Work Hardening: It works prone to over hardening under forming operations and thus resulting in the loss of ductility that could be regained by annealing or heat treatment.

  • Cost: For instance, other for grades than AISI 309Cb+Ta stainless steel can cost relatively a lot, so the affordability is affected in some applications.

  • Surface Finish: Getting any given smooth surface finish can be difficult especially when the work-hardening property of this material is relocated at machining stage.

  • Sensitivity to Chloride: AISI 309Cb+Ta is at risk of getting localized corrosion in chloride rich, surroundings, so it is essential to take a cautious approach when choosing this alloy for marine or coastal structures.

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