Interesting facts about Cobalt in steel

Co does not form any carbides. It inhibits grain growth at elevated temperatures and pronouncedly improves retention of temper and high temperature strength. Therefore, used frequently as alloying element in high speed steels, hot forming tool steels, creep-resistant and high temperature materials. Promotes graphite formation. In large quantities, increases remanence, coercive field intensity and thermal conductivity. Therefore, alloying base for super high quality permanent magnet steels and alloys. Under the influence of neutral irradiation, the pronouncedly radioactive isotope⁶⁰, Co is formed, for which reason Co is undesirable in steels for atomic reactors.