Carbon compound of niobium with high hardness (approx. 2400HV) and high melting point (approx. 3420°C) formed due to the extraordinary affinity to carbon.
This hard material can be formed in both steel and iron casting alloys and is occasionally found as a structural component in piston rings (see J-Alloy) where the high wear resistance is utilized. Very small contents of this alloying element are sufficient to produce carbides (niobium only offers low solubility in the matrix) and this neither influences the solidification nor the the transformation processes in solid state.