The composition of Alloy K500 and Alloy 400 is almost identical, so their corrosion resistance is comparable. The key difference is strength: Alloy 400 is much lower, which is why Alloy K500 was developed.
Alloy 400 (Monel® 400, UNS N04400, 2.4360) is a nickel-copper alloy that resists seawater and steam at high temperatures, and is frequently used in the chemical, oil and marine industries. It is a solution-strengthened material with good toughness, strength and corrosion resistance at temperatures up to 400°C. It also resists hydrofluoric and dilute non-oxidising acids, alkalis and salts, and is not susceptible to stress corrosion cracking.
How Alloy K500 gains its strength
Alloy K500 (Monel K500, UNS N05500, 2.4375) contains small additions of aluminium and titanium, 3-4% in total. These combine to form microscopic precipitates that are controlled through heat treatment. After forging or rolling, the round bars are aged - held at an elevated temperature for several hours, then cooled slowly in air - so that as much aluminium and titanium as possible precipitates out of solution into a finely dispersed network.
These precipitates give a significant uplift in mechanical properties: the yield strength can be up to 4x greater and the tensile strength up to 2x greater than Alloy 400.
We supply a wide range of Alloy K500 from 5/8" up to 10" diameter solid round bar.