Tantalum is an amazing element due to its unrivaled corrosion resistance. As most corrosion resistant alloys have corrosion rates in strong acids, tantalum metal typically has none. Because of this characteristic, tantalum is ideal as a coated diffusion surface and is often used to protect critical stainless steel process equipment from strong acids. However in lethal services, this is not enough, as products need to be fail-safe should there be an unforeseen breach in the tantalum surface and the base steel substrate is exposed.
Because of this reality, coatings have been typically avoided, even if they substantially outperform solid alloys, with preference for predictably. However, what if a familiar predictable base substrate could be used in combination with a tantalum diffusion surface? This not only could provide a significant boost in performance due to tantalum’s corrosion resistance but also provide the predictability of a solid alloy….Perhaps, the best of both worlds.
Fortunately, tantalum diffusion surfaces could be produced in combination with many different substrates to create a fail-safe solution. For example, a tantalum diffusion surface could be made in combination with nickel alloys like Hastelloy C276 or Inconel 625. Also tantalum diffusion surfaces could be made on non-metalics like ceramics and graphite. In these cases where corrosion resistant alloys and non-metalics would not perform well on their own, combining them with a tantalum diffusion surface may not only give a significant boost in terms of corrosion resistance but will also provide a fail-safe highly predictable mode of failure should there be a breach.
Determining the best substrate to use in combination with a tantalum diffusion surface will be a balance of a few factors such as:
- Mechanical Needs
- Chemical Resistance
- Temperature Range
- Historical Material Usage
Contact our materials / corrosion engineers to learn more about the options available for your application or see our Ultra-Safe product for more info.