Research On The Preparation And Properties Of Different Mo Content NiCrMo Alloy

Under the dual crisis of the rapid growth in global energy consumption and environmental pollution, the world began to focus its attention on the use of biomass energy power generation. In the near future, the current biomass power generating capacity is expected to account for 20% of the total capacity. To achieve this goal, one of the obstacles is caused by the high temperature corrosion of superheater area, the main reason of which is the high Cl content in biomass fuels and the deposition of alkali chloride.According to the corrosion mechanism and advanced corrosion resistant alloy system, a new NiCrMoX corrosion resistant alloy is designed and prepared, whose phase composition is:the first precipitation of Ni-Cr-Co-Mo solid solution (white area), and the second precipitation of Mo-rich phase (gray bar area). The salt solution immersion test and high temperature molten salt corrosion test were carried out, the corrosion surface morphology and corrosion products were analyzed by SEM and EDS, and the phase composition was analyzed by XRD.The results show that as the HC1 concentration increased from 10% to 20%, the average corrosion weight loss rate of alloy samples is doubled. High temperature molten salt corrosion test results show that,9Mo alloy has the highest average corrosion rate, the average corrosion rate of 13Mo is about 1g/(h·m2), whose corrosion resistance property is the best, which is better than the 18Mo alloy. The corrosion products are mainly NiCr2O4 and Cr2O3, but the porous oxide layer can not be closely integrated with the substrate, Ni and Cr oxidation products react with the molten salt, resulting in reduced protection oxide layer, and the alloy substrates are corroded because that Cl goes through the oxide layer to the interface. The NiCrMo13 alloy has the best chlorine corrosion resistant property.