Nickel superalloy vs Stainless steel
Nickel superalloy and Stainless steel are genuine alternatives to one another — a choice somebody actually makes — and differ on 2 measured properties, density most clearly.
Nickel superalloy vs Stainless steel
Nickel superalloy
A nickel alloy that keeps its strength at four fifths of its own melting point — the reason a jet engine works, and the only large use of rhenium there is.
Stainless steel
Steel with enough chromium to repair its own oxide film — the material that made corrosion a design choice rather than a certainty.
| Property | Nickel superalloy | Stainless steel |
|---|---|---|
| Density | 8.2–8.9 g/cm³ higher | 7.7–8 g/cm³ |
| Electrical conductivity Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 1.45 MS/m |
| Melting point | 1300–1400 °C | 1370–1450 °C higher |
| Tensile strength Only one of the two has a figure we can stand behind, so there is nothing to compare. | Not known | 480–2000 MPa |
Choosing between them
Nickel superalloy is recorded as a substitute for Stainless steel — better at temperature, stronger.
What it gives up: Roughly ten times the cost, and it is only worth it above about 600 °C where stainless has lost its strength.
In this application, on the evidence cited above.