Investigation of Substrate Effects on Type Two Hot Corrosion of Marine Gas Turbine Materials

摘要

CoCrAlY coated Modifications of Rene 80 (a Ni base superalloy) were tested for resistance to Type Two (Low Temperature) Hot Corrosion. The effects of Ti and Hf in the substrate (normally 5.0% and 0.0% respectively) and the presence of a Pt underlayer were investigated. Certain trends were distinguishable from the data obtained. Titanium alone was found to be beneficial, Titanium in conjunction with a platinum underlayer was found to be detrimental while platinum underlayers in conjunction with low titanium concentrations in the substrate were found to be beneficial. Hafnium had a noticeable, but irregular effect only on specimens with intermediate titanium concentrations. All the above effects were found to be diffusion related. This study also made certain refinements to the NPS Hot Corrosion Test Program and direct correlation of data obtained from different runs if now justified.