Nickel-Chromium-Molybdenum alloys (Ni-Cr-Mo) are highly resistant to general corrosion, localized corrosion and environmentally assisted cracking (EAC). Cr acts as a beneficial element under oxidizing acidic conditions and Mo under reducing conditions. All three elements (Ni, Cr and Mo) act synergisti- cally to provide resistance to EAC in environments such as hot concentrated chloride solutions. Ni-Cr- Mo alloys may suffer EAC in environments such as hot caustic solutions, hot wet hydrofluoric acid (HF) solutions and in super critical water oxidation (SCWO) applications. Not all the Ni-Cr-Mo alloys have the same susceptibility to cracking in the mentioned environments. Most of the available data regarding EAC is for the oldest Ni-Cr-Mo alloys such as N 10276 and N06625.
Keywords: Environmentally Assisted Cracking, Nickel-Chromium-Molybdenum Alloys, Alkalis, Wet Hydrofluoric Acid, Supercritical Water Oxidation.