Influence of Al on the High Temperature corrosion behaviour of Inconel 617 in VHTR primary coolant atmosphere

Due to the specific in service VHTR conditions, the corrosion behaviour of Inconel 617, candidate alloy for the IHX design, has been investigated at elevated temperatures in representative helium containing impurities (CO, H2O, H2 and CH4) in the range of 'bar. The role of Al in the corrosion behaviour of IN617 is investigated using Ni-22Cr-9Mo base model alloys containing different Al levels (from 0 to 2wt.%).