Which is better, nickel or stainless steel? Nickel Alloys
When reviewing the most appropriate alloy for a particular application, it is necessary to consider a broader range of criteria. As well as performance in the specific environment (corrosion resistance, mechanical properties), thought should be given to the ease of fabrication, availability of the alloy in the most convenient sizes and of course the cost of ownership.
With such a wide range of different stainless steel and nickel alloys available, it is quite possible that several may all be suitable for a given application. Therefore, other considerations could include the ease of inspection and/or replacement in the application (providing a reason to ‘over specify’ if this option is problematic) and the existence of a successful operating track record.
Super duplex alloys score well on a ‘balanced scorecard’ given their excellent combination of high strength, corrosion resistance and competitive pricing compared with nickel alloys. However, they may be restricted in use at very low or very high temperatures, whilst selected nickel alloys can outperform their corrosion resistance in particular environments.