Inconel Springs

The most common reason we see Inconel used is for elevated temperature applications and the best grade for this is Inconel 718 to AMS5962. Inconel 718 requires an ageing treatment to release its full mechanical properties which can be costly, but this then enables it to be used between -200°C to +550°C where it will outperform the mechanical properties of any Inconel X750 or Nimonic 90.

One other option is to use Inconel X750 which can be bought in 2 different conditions No1 Temper (AMS5698) and Spring Temper (AMS5699) which each has its own merits. One thing to watch out for with this material is the heat treatment, as this will not only determine the Tensile strength (which can be as low as 900 Mpa (130 KSI) or as high as 1750Mpa (254 KSI)), but it will also determine the maximum operating temperature which can be limited to +370°C or increased to +550°C depending on the thermal treatment.

Another benefit of using Inconel X750 (or indeed Inconel 718) is its corrosion resistance in a sulphide environment. Material intended for this use can be certified to NACE MR0175 requirements as long as the heat treatment is varied to ensure compliance.